November 2020 - Linux-audit - Linux-Audit List Archives

[PATCH ghak124 v3] audit: log nftables configuration change events

by Richard Guy Briggs

iptables, ip6tables, arptables and ebtables table registration, replacement and unregistration configuration events are logged for the native (legacy) iptables setsockopt api, but not for the nftables netlink api which is used by the nft-variant of iptables in addition to nftables itself. Add calls to log the configuration actions in the nftables netlink api. This uses the same NETFILTER_CFG record format but overloads the table field. type=NETFILTER_CFG msg=audit(2020-05-28 17:46:41.878:162) : table=?:0;?:0 family=unspecified entries=2 op=nft_register_gen pid=396 subj=system_u:system_r:firewalld_t:s0 comm=firewalld ... type=NETFILTER_CFG msg=audit(2020-05-28 17:46:41.878:162) : table=firewalld:1;?:0 family=inet entries=0 op=nft_register_table pid=396 subj=system_u:system_r:firewalld_t:s0 comm=firewalld ... type=NETFILTER_CFG msg=audit(2020-05-28 17:46:41.911:163) : table=firewalld:1;filter_FORWARD:85 family=inet entries=8 op=nft_register_chain pid=396 subj=system_u:system_r:firewalld_t:s0 comm=firewalld ... type=NETFILTER_CFG msg=audit(2020-05-28 17:46:41.911:163) : table=firewalld:1;filter_FORWARD:85 family=inet entries=101 op=nft_register_rule pid=396 subj=system_u:system_r:firewalld_t:s0 comm=firewalld ... type=NETFILTER_CFG msg=audit(2020-05-28 17:46:41.911:163) : table=firewalld:1;__set0:87 family=inet entries=87 op=nft_register_setelem pid=396 subj=system_u:system_r:firewalld_t:s0 comm=firewalld ... type=NETFILTER_CFG msg=audit(2020-05-28 17:46:41.911:163) : table=firewalld:1;__set0:87 family=inet entries=0 op=nft_register_set pid=396 subj=system_u:system_r:firewalld_t:s0 comm=firewalld For further information please see issue https://github.com/linux-audit/audit-kernel/issues/124 Signed-off-by: Richard Guy Briggs <rgb(a)redhat.com> --- Changelog: v3: - inline message type rather than table v2: - differentiate between xtables and nftables - add set, setelem, obj, flowtable, gen - use nentries field as appropriate per type - overload the "tables" field with table handle and chain/set/flowtable include/linux/audit.h | 18 ++++++++ kernel/auditsc.c | 24 ++++++++-- net/netfilter/nf_tables_api.c | 103 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 142 insertions(+), 3 deletions(-) diff --git a/include/linux/audit.h b/include/linux/audit.h index 3fcd9ee49734..604ede630580 100644 --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -12,6 +12,7 @@ #include <linux/sched.h> #include <linux/ptrace.h> #include <uapi/linux/audit.h> +#include <uapi/linux/netfilter/nf_tables.h> #define AUDIT_INO_UNSET ((unsigned long)-1) #define AUDIT_DEV_UNSET ((dev_t)-1) @@ -98,6 +99,23 @@ enum audit_nfcfgop { AUDIT_XT_OP_REGISTER, AUDIT_XT_OP_REPLACE, AUDIT_XT_OP_UNREGISTER, + AUDIT_NFT_OP_TABLE_REGISTER, + AUDIT_NFT_OP_TABLE_UNREGISTER, + AUDIT_NFT_OP_CHAIN_REGISTER, + AUDIT_NFT_OP_CHAIN_UNREGISTER, + AUDIT_NFT_OP_RULE_REGISTER, + AUDIT_NFT_OP_RULE_UNREGISTER, + AUDIT_NFT_OP_SET_REGISTER, + AUDIT_NFT_OP_SET_UNREGISTER, + AUDIT_NFT_OP_SETELEM_REGISTER, + AUDIT_NFT_OP_SETELEM_UNREGISTER, + AUDIT_NFT_OP_GEN_REGISTER, + AUDIT_NFT_OP_OBJ_REGISTER, + AUDIT_NFT_OP_OBJ_UNREGISTER, + AUDIT_NFT_OP_OBJ_RESET, + AUDIT_NFT_OP_FLOWTABLE_REGISTER, + AUDIT_NFT_OP_FLOWTABLE_UNREGISTER, + AUDIT_NFT_OP_INVALID, }; extern int is_audit_feature_set(int which); diff --git a/kernel/auditsc.c b/kernel/auditsc.c index 468a23390457..3a9100e95fda 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -75,6 +75,7 @@ #include <linux/uaccess.h> #include <linux/fsnotify_backend.h> #include <uapi/linux/limits.h> +#include <uapi/linux/netfilter/nf_tables.h> #include "audit.h" @@ -136,9 +137,26 @@ struct audit_nfcfgop_tab { }; static const struct audit_nfcfgop_tab audit_nfcfgs[] = { - { AUDIT_XT_OP_REGISTER, "register" }, - { AUDIT_XT_OP_REPLACE, "replace" }, - { AUDIT_XT_OP_UNREGISTER, "unregister" }, + { AUDIT_XT_OP_REGISTER, "xt_register" }, + { AUDIT_XT_OP_REPLACE, "xt_replace" }, + { AUDIT_XT_OP_UNREGISTER, "xt_unregister" }, + { AUDIT_NFT_OP_TABLE_REGISTER, "nft_register_table" }, + { AUDIT_NFT_OP_TABLE_UNREGISTER, "nft_unregister_table" }, + { AUDIT_NFT_OP_CHAIN_REGISTER, "nft_register_chain" }, + { AUDIT_NFT_OP_CHAIN_UNREGISTER, "nft_unregister_chain" }, + { AUDIT_NFT_OP_RULE_REGISTER, "nft_register_rule" }, + { AUDIT_NFT_OP_RULE_UNREGISTER, "nft_unregister_rule" }, + { AUDIT_NFT_OP_SET_REGISTER, "nft_register_set" }, + { AUDIT_NFT_OP_SET_UNREGISTER, "nft_unregister_set" }, + { AUDIT_NFT_OP_SETELEM_REGISTER, "nft_register_setelem" }, + { AUDIT_NFT_OP_SETELEM_UNREGISTER, "nft_unregister_setelem" }, + { AUDIT_NFT_OP_GEN_REGISTER, "nft_register_gen" }, + { AUDIT_NFT_OP_OBJ_REGISTER, "nft_register_obj" }, + { AUDIT_NFT_OP_OBJ_UNREGISTER, "nft_unregister_obj" }, + { AUDIT_NFT_OP_OBJ_RESET, "nft_reset_obj" }, + { AUDIT_NFT_OP_FLOWTABLE_REGISTER, "nft_register_flowtable" }, + { AUDIT_NFT_OP_FLOWTABLE_UNREGISTER, "nft_unregister_flowtable" }, + { AUDIT_NFT_OP_INVALID, "nft_invalid" }, }; static int audit_match_perm(struct audit_context *ctx, int mask) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 3558e76e2733..b9e7440cc87d 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -12,6 +12,7 @@ #include <linux/netlink.h> #include <linux/vmalloc.h> #include <linux/rhashtable.h> +#include <linux/audit.h> #include <linux/netfilter.h> #include <linux/netfilter/nfnetlink.h> #include <linux/netfilter/nf_tables.h> @@ -693,6 +694,16 @@ static void nf_tables_table_notify(const struct nft_ctx *ctx, int event) { struct sk_buff *skb; int err; + char *buf = kasprintf(GFP_KERNEL, "%s:%llu;?:0", + ctx->table->name, ctx->table->handle); + + audit_log_nfcfg(buf, + ctx->family, + ctx->table->use, + event == NFT_MSG_NEWTABLE ? + AUDIT_NFT_OP_TABLE_REGISTER : + AUDIT_NFT_OP_TABLE_UNREGISTER); + kfree(buf); if (!ctx->report && !nfnetlink_has_listeners(ctx->net, NFNLGRP_NFTABLES)) @@ -1428,6 +1439,17 @@ static void nf_tables_chain_notify(const struct nft_ctx *ctx, int event) { struct sk_buff *skb; int err; + char *buf = kasprintf(GFP_KERNEL, "%s:%llu;%s:%llu", + ctx->table->name, ctx->table->handle, + ctx->chain->name, ctx->chain->handle); + + audit_log_nfcfg(buf, + ctx->family, + ctx->chain->use, + event == NFT_MSG_NEWCHAIN ? + AUDIT_NFT_OP_CHAIN_REGISTER : + AUDIT_NFT_OP_CHAIN_UNREGISTER); + kfree(buf); if (!ctx->report && !nfnetlink_has_listeners(ctx->net, NFNLGRP_NFTABLES)) @@ -2691,6 +2713,17 @@ static void nf_tables_rule_notify(const struct nft_ctx *ctx, { struct sk_buff *skb; int err; + char *buf = kasprintf(GFP_KERNEL, "%s:%llu;%s:%llu", + ctx->table->name, ctx->table->handle, + ctx->chain->name, ctx->chain->handle); + + audit_log_nfcfg(buf, + ctx->family, + rule->handle, + event == NFT_MSG_NEWRULE ? + AUDIT_NFT_OP_RULE_REGISTER : + AUDIT_NFT_OP_RULE_UNREGISTER); + kfree(buf); if (!ctx->report && !nfnetlink_has_listeners(ctx->net, NFNLGRP_NFTABLES)) @@ -3693,6 +3726,17 @@ static void nf_tables_set_notify(const struct nft_ctx *ctx, struct sk_buff *skb; u32 portid = ctx->portid; int err; + char *buf = kasprintf(gfp_flags, "%s:%llu;%s:%llu", + ctx->table->name, ctx->table->handle, + set->name, set->handle); + + audit_log_nfcfg(buf, + ctx->family, + set->field_count, + event == NFT_MSG_NEWSET ? + AUDIT_NFT_OP_SET_REGISTER : + AUDIT_NFT_OP_SET_UNREGISTER); + kfree(buf); if (!ctx->report && !nfnetlink_has_listeners(ctx->net, NFNLGRP_NFTABLES)) @@ -4809,6 +4853,17 @@ static void nf_tables_setelem_notify(const struct nft_ctx *ctx, u32 portid = ctx->portid; struct sk_buff *skb; int err; + char *buf = kasprintf(GFP_KERNEL, "%s:%llu;%s:%llu", + ctx->table->name, ctx->table->handle, + set->name, set->handle); + + audit_log_nfcfg(buf, + ctx->family, + set->handle, + event == NFT_MSG_NEWSETELEM ? + AUDIT_NFT_OP_SETELEM_REGISTER : + AUDIT_NFT_OP_SETELEM_UNREGISTER); + kfree(buf); if (!ctx->report && !nfnetlink_has_listeners(net, NFNLGRP_NFTABLES)) return; @@ -5890,6 +5945,19 @@ static int nf_tables_dump_obj(struct sk_buff *skb, struct netlink_callback *cb) obj->ops->type->type != filter->type) goto cont; + if (reset) { + char *buf = kasprintf(GFP_KERNEL, + "%s:%llu;?:0", + table->name, + table->handle); + + audit_log_nfcfg(buf, + family, + obj->handle, + AUDIT_NFT_OP_OBJ_RESET); + kfree(buf); + } + if (nf_tables_fill_obj_info(skb, net, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, NFT_MSG_NEWOBJ, @@ -6000,6 +6068,17 @@ static int nf_tables_getobj(struct net *net, struct sock *nlsk, if (NFNL_MSG_TYPE(nlh->nlmsg_type) == NFT_MSG_GETOBJ_RESET) reset = true; + if (reset) { + char *buf = kasprintf(GFP_KERNEL, "%s:%llu;?:0", + table->name, table->handle); + + audit_log_nfcfg(buf, + family, + obj->handle, + AUDIT_NFT_OP_OBJ_RESET); + kfree(buf); + } + err = nf_tables_fill_obj_info(skb2, net, NETLINK_CB(skb).portid, nlh->nlmsg_seq, NFT_MSG_NEWOBJ, 0, family, table, obj, reset); @@ -6075,6 +6154,16 @@ void nft_obj_notify(struct net *net, const struct nft_table *table, { struct sk_buff *skb; int err; + char *buf = kasprintf(GFP_KERNEL, "%s:%llu;?:0", + table->name, table->handle); + + audit_log_nfcfg(buf, + family, + obj->handle, + event == NFT_MSG_NEWOBJ ? + AUDIT_NFT_OP_OBJ_REGISTER : + AUDIT_NFT_OP_OBJ_UNREGISTER); + kfree(buf); if (!report && !nfnetlink_has_listeners(net, NFNLGRP_NFTABLES)) @@ -6701,6 +6790,17 @@ static void nf_tables_flowtable_notify(struct nft_ctx *ctx, { struct sk_buff *skb; int err; + char *buf = kasprintf(GFP_KERNEL, "%s:%llu;%s:%llu", + flowtable->table->name, flowtable->table->handle, + flowtable->name, flowtable->handle); + + audit_log_nfcfg(buf, + ctx->family, + flowtable->hooknum, + event == NFT_MSG_NEWFLOWTABLE ? + AUDIT_NFT_OP_FLOWTABLE_REGISTER : + AUDIT_NFT_OP_FLOWTABLE_UNREGISTER); + kfree(buf); if (ctx->report && !nfnetlink_has_listeners(ctx->net, NFNLGRP_NFTABLES)) @@ -6822,6 +6922,9 @@ static void nf_tables_gen_notify(struct net *net, struct sk_buff *skb, struct sk_buff *skb2; int err; + audit_log_nfcfg("?:0;?:0", 0, net->nft.base_seq, + AUDIT_NFT_OP_GEN_REGISTER); + if (nlmsg_report(nlh) && !nfnetlink_has_listeners(net, NFNLGRP_NFTABLES)) return; -- 1.8.3.1

3 years, 10 months

6
26
0 / 0

[PATCH v22 00/23] LSM: Module stacking for AppArmor

by Casey Schaufler

This patchset provides the changes required for the AppArmor security module to stack safely with any other. v23: Rebase to 5.10-rc4 Incorporate feedback from v22 - Change /proc/*/attr/display to /proc/*/attr/interface_lsm to make the purpose clearer. (patch 0012) - Include ABI documentation. (patch 0012, 0022) - Introduce LSM documentation updates with the patches where the interfaces are added rather than at the end. (patch 0012, 0022) Include more maintainers and mail lists in To: and Cc: directives. v22: Rebase to 5.10-rc1 v21: Rebase to 5.9-rc4 Incorporate feedback from v20 - Further revert UDS SO_PEERSEC to use scaffolding around the interfaces that use lsmblobs and store only a single secid. The possibility of multiple security modules requiring data here is still a future problem. - Incorporate Richard Guy Briggs' non-syscall auxiliary records patch (patch 0019-0021) in place of my "supplimental" records implementation. [I'm not sure I've given proper attestation. I will correct as appropriate] v20: Rebase to 5.9-rc1 Change the BPF security module to use the lsmblob data. (patch 0002) Repair length logic in subject label processing (patch 0015) Handle -EINVAL from the empty BPF setprocattr hook (patch 0020) Correct length processing in append_ctx() (patch 0022) v19: Rebase to 5.8-rc6 Incorporate feedback from v18 - Revert UDS SO_PEERSEC implementation to use lsmblobs directly, rather than allocating as needed. The correct treatment of out-of-memory conditions in the later case is difficult to define. (patch 0005) - Use a size_t in append_ctx() (patch 0021) - Fix a memory leak when creating compound contexts. (patch 0021) Fix build error when CONFIG_SECURITY isn't set (patch 0013) Fix build error when CONFIG_SECURITY isn't set (patch 0020) Fix build error when CONFIG_SECURITY isn't set (patch 0021) v18: Rebase to 5.8-rc3 Incorporate feedback from v17 - Null pointer checking in UDS (patch 0005) Match changes in IMA code (patch 0012) Fix the behavior of LSM context supplimental audit records so that there's always exactly one when it's appropriate for there to be one. This is a substantial change that requires extention of the audit_context beyond syscall events. (patch 0020) v17: Rebase to 5.7-rc4 v16: Rebase to 5.6 Incorporate feedback from v15 - Thanks Stephen, Mimi and Paul - Generally improve commit messages WRT scaffolding - Comment ima_lsm_isset() (patch 0002) - Some question may remain on IMA warning (patch 0002) - Mark lsm_slot as __lsm_ro_after_init not __init_data (patch 0002) - Change name of lsmblob variable in ima_match_rules() (patch 0003) - Instead of putting a struct lsmblob into the unix_skb_parms structure put a pointer to an allocated instance. There is currently only space for 5 u32's in unix_skb_parms and it is likely to get even tighter. Fortunately, the lifecycle management of the allocated lsmblob is simple. (patch 0005) - Dropped Acks due to the above change (patch 0005) - Improved commentary on secmark labeling scaffolding. (patch 0006) - Reduced secmark related labeling scaffolding. (patch 0006) - Replace use of the zeroth entry of an lsmblob in scaffolding with a function lsmblob_value() to hopefully make it less obscure. (patch 0006) - Convert security_secmark_relabel_packet to use lsmblob as this reduces much of the most contentious scaffolding. (patch 0006) - Dropped Acks due to the above change (patch 0006) - Added BUILD_BUG_ON() for CIPSO tag 6. (patch 0018) - Reworked audit subject information. Instead of adding fields in the middle of existing records add a new record to the event. When a separate record is required use subj="?". (patch 0020) - Dropped Acks due to the above change (patch 0020) - Reworked audit object information. Instead of adding fields in the middle of existing records add a new record to the event. When a separate record is required use obj="?". (patch 0021) - Dropped Acks due to the above change (patch 0021) - Enhanced documentation (patch 0022) - Removed unnecessary error code check in security_getprocattr() (patch 0021) v15: Rebase to 5.6-rc1 - Revise IMA data use (patch 0002) Incorporate feedback from v14 - Fix lockdown module registration naming (patch 0002) - Revise how /proc/self/attr/context is gathered. (patch 0022) - Revise access modes on /proc/self/attr/context. (patch 0022) - Revise documentation on LSM external interfaces. (patch 0022) v14: Rebase to 5.5-rc5 Incorporate feedback from v13 - Use an array of audit rules (patch 0002) - Significant change, removed Acks (patch 0002) - Remove unneeded include (patch 0013) - Use context.len correctly (patch 0015) - Reorder code to be more sensible (patch 0016) - Drop SO_PEERCONTEXT as it's not needed yet (patch 0023) v13: Rebase to 5.5-rc2 Incorporate feedback from v12 - Print lsmblob size with %z (Patch 0002) - Convert lockdown LSM initialization. (Patch 0002) - Restore error check in nft_secmark_compute_secid (Patch 0006) - Correct blob scaffolding in ima_must_appraise() (Patch 0009) - Make security_setprocattr() clearer (Patch 0013) - Use lsm_task_display more widely (Patch 0013) - Use passed size in lsmcontext_init() (Patch 0014) - Don't add a smack_release_secctx() hook (Patch 0014) - Don't print warning in security_release_secctx() (Patch 0014) - Don't duplicate the label in nfs4_label_init_security() (Patch 0016) - Remove reviewed-by as code has significant change (Patch 0016) - Send the entire lsmblob for Tag 6 (Patch 0019) - Fix description of socket_getpeersec_stream parameters (Patch 0023) - Retain LSMBLOB_FIRST. What was I thinking? (Patch 0023) - Add compound context to LSM documentation (Patch 0023) v12: Rebase to 5.5-rc1 Fixed a couple of incorrect contractions in the text. v11: Rebase to 5.4-rc6 Incorporate feedback from v10 - Disambiguate reading /proc/.../attr/display by restricting all use of the interface to the current process. - Fix a merge error in AppArmor's display attribute check v10: Ask the security modules if the display can be changed. v9: There is no version 9 v8: Incorporate feedback from v7 - Minor clean-up in display value management - refactor "compound" context creation to use a common append_ctx() function. v7: Incorporate feedback from v6 - Make setting the display a privileged operation. The availability of compound contexts reduces the need for setting the display. v6: Incorporate feedback from v5 - Add subj_<lsm>= and obj_<lsm>= fields to audit records - Add /proc/.../attr/context to get the full context in lsmname\0value\0... format as suggested by Simon McVittie - Add SO_PEERCONTEXT for getsockopt() to get the full context in the same format, also suggested by Simon McVittie. - Add /sys/kernel/security/lsm_display_default to provide the display default value. v5: Incorporate feedback from v4 - Initialize the lsmcontext in security_secid_to_secctx() - Clear the lsmcontext in all security_release_secctx() cases - Don't use the "display" on strictly internal context interfaces. - The SELinux binder hooks check for cases where the context "display" isn't compatible with SELinux. v4: Incorporate feedback from v3 - Mark new lsm_<blob>_alloc functions static - Replace the lsm and slot fields of the security_hook_list with a pointer to a LSM allocated lsm_id structure. The LSM identifies if it needs a slot explicitly. Use the lsm_id rather than make security_add_hooks return the slot value. - Validate slot values used in security.c - Reworked the "display" process attribute handling so that it works right and doesn't use goofy list processing. - fix display value check in dentry_init_security - Replace audit_log of secids with '?' instead of deleting the audit log v3: Incorporate feedback from v2 - Make lsmblob parameter and variable names more meaningful, changing "le" and "l" to "blob". - Improve consistency of constant naming. - Do more sanity checking during LSM initialization. - Be a bit clearer about what is temporary scaffolding. - Rather than clutter security_getpeersec_dgram with otherwise unnecessary checks remove the apparmor stub, which does nothing useful. Patch 0001 moves management of the sock security blob from the individual modules to the infrastructure. Patches 0002-0011 replace system use of a "secid" with a structure "lsmblob" containing information from the security modules to be held and reused later. At this point lsmblob contains an array of u32 secids, one "slot" for each of the security modules compiled into the kernel that used secids. A "slot" is allocated when a security module requests one. The infrastructure is changed to use the slot number to pass the correct secid to or from the security module hooks. It is important that the lsmblob be a fixed size entity that does not have to be allocated. Several of the places where it is used would have performance and/or locking issues with dynamic allocation. Patch 0012 provides a mechanism for a process to identify which security module's hooks should be used when displaying or converting a security context string. A new interface /proc/self/attr/interface_lsm contains the name of the security module to show. Reading from this file will present the name of the module, while writing to it will set the value. Only names of active security modules are accepted. Internally, the name is translated to the appropriate "slot" number for the module which is then stored in the task security blob. Setting the display requires that all modules using the /proc interfaces allow the transition. The interface LSM of other processess can be neither read nor written. All suggested cases for reading the interface LSM of a different process have race conditions. Patch 0013 Starts the process of changing how a security context is represented. Since it is possible for a security context to have been generated by more than one security module it is now necessary to note which module created a security context so that the correct "release" hook can be called. There are several places where the module that created a security context cannot be inferred. This is achieved by introducing a "lsmcontext" structure which contains the context string, its length and the "slot" number of the security module that created it. The security_release_secctx() interface is changed, replacing the (string,len) pointer pair with a lsmcontext pointer. Patches 0014-0016 convert the security interfaces from (string,len) pointer pairs to a lsmcontext pointer. The slot number identifying the creating module is added by the infrastructure. Where the security context is stored for extended periods the data type is changed. The Netlabel code is converted to save lsmblob structures instead of secids in Patch 0017. This is not strictly necessary as there can only be one security module that uses Netlabel at this point. Using a lsmblob is much cleaner, as the interfaces that use the data have all been converted. Patch 0018 adds checks to the binder hooks which verify that both ends of a transaction use the same interface LSM. Patches 0019-0021 add addition audit records for subject and object LSM data when there are multiple security modules with such data. The AUDIT_MAC_TASK_CONTEXTS record is used in conjuction with a "subj=?" field to identify the subject data. The AUDIT_MAC_OBJ_CONTEXTS record is used in conjuction with a "obj=?" field to identify the object data. The AUDIT_MAC_TASK_CONTEXTS record identifies the security module with the data: "subj_selinux=xyz_t subj_apparmor=abc". The AUDIT_MAC_OBJ_CONTEXTS record identifies the security module with the data: "obj_selinux=xyz_t obj_apparmor=abc". While AUDIT_MAC_TASK_CONTEXTS records will always contain an entry for each possible security modules, AUDIT_MAC_OBJ_CONTEXTS records will only contain entries for security modules for which the object in question has data. An example of the MAC_TASK_CONTEXTS (1420) record is: type=UNKNOWN[1420] msg=audit(1600880931.832:113) subj_apparmor==unconfined subj_smack=_ An example of the MAC_OBJ_CONTEXTS (1421) record is: type=UNKNOWN[1421] msg=audit(1601152467.009:1050): obj_selinux=unconfined_u:object_r:user_home_t:s0 Patch 0022 adds a new interface for getting the compound security contexts, /proc/self/attr/context. An example of the content of this file is: selinux\0one_u:one_r:one_t:s0-s0:c0.c1023\0apparmor\0unconfined\0 Finally, with all interference on the AppArmor hooks removed, Patch 0023 removes the exclusive bit from AppArmor. An unnecessary stub hook was also removed. The Ubuntu project is using an earlier version of this patchset in their distribution to enable stacking for containers. Performance measurements to date have the change within the "noise". The sockperf and dbench results are on the order of 0.2% to 0.8% difference, with better performance being as common as worse. The benchmarks were run with AppArmor and Smack on Ubuntu. https://github.com/cschaufler/lsm-stacking.git#stack-5.10-rc4-v23 Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com> ---

3 years, 11 months

3
39
0 / 0

[PATCH v2] audit: report audit wait metric in audit status reply

by Max Englander

In environments where the preservation of audit events and predictable usage of system memory are prioritized, admins may use a combination of --backlog_wait_time and -b options at the risk of degraded performance resulting from backlog waiting. In some cases, this risk may be preferred to lost events or unbounded memory usage. Ideally, this risk can be mitigated by making adjustments when backlog waiting is detected. However, detection can be diffult using the currently available metrics. For example, an admin attempting to debug degraded performance may falsely believe a full backlog indicates backlog waiting. It may turn out the backlog frequently fills up but drains quickly. To make it easier to reliably track degraded performance to backlog waiting, this patch makes the following changes: Add a new field backlog_wait_sum to the audit status reply. Initialize this field to zero. Add to this field the total time spent by the current task on scheduled timeouts while the backlog limit is exceeded. Tested on Ubuntu 18.04 using complementary changes to the audit userspace: https://github.com/linux-audit/audit-userspace/pull/134. Signed-off-by: Max Englander <max.englander(a)gmail.com> --- Patch changelogs between v1 and v2: - Instead of printing a warning when backlog waiting occurs, add duration of backlog waiting to cumulative sum, and report this sum in audit status reply. include/uapi/linux/audit.h | 7 ++++++- kernel/audit.c | 9 +++++++++ 2 files changed, 15 insertions(+), 1 deletion(-) diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h index a534d71e689a..ea0cc364beca 100644 --- a/include/uapi/linux/audit.h +++ b/include/uapi/linux/audit.h @@ -340,6 +340,7 @@ enum { #define AUDIT_STATUS_BACKLOG_LIMIT 0x0010 #define AUDIT_STATUS_BACKLOG_WAIT_TIME 0x0020 #define AUDIT_STATUS_LOST 0x0040 +#define AUDIT_STATUS_BACKLOG_WAIT_SUM 0x0080 #define AUDIT_FEATURE_BITMAP_BACKLOG_LIMIT 0x00000001 #define AUDIT_FEATURE_BITMAP_BACKLOG_WAIT_TIME 0x00000002 @@ -348,6 +349,7 @@ enum { #define AUDIT_FEATURE_BITMAP_SESSIONID_FILTER 0x00000010 #define AUDIT_FEATURE_BITMAP_LOST_RESET 0x00000020 #define AUDIT_FEATURE_BITMAP_FILTER_FS 0x00000040 +#define AUDIT_FEATURE_BITMAP_BACKLOG_WAIT_SUM 0x00000080 #define AUDIT_FEATURE_BITMAP_ALL (AUDIT_FEATURE_BITMAP_BACKLOG_LIMIT | \ AUDIT_FEATURE_BITMAP_BACKLOG_WAIT_TIME | \ @@ -355,12 +357,14 @@ enum { AUDIT_FEATURE_BITMAP_EXCLUDE_EXTEND | \ AUDIT_FEATURE_BITMAP_SESSIONID_FILTER | \ AUDIT_FEATURE_BITMAP_LOST_RESET | \ - AUDIT_FEATURE_BITMAP_FILTER_FS) + AUDIT_FEATURE_BITMAP_FILTER_FS | \ + AUDIT_FEATURE_BITMAP_BACKLOG_WAIT_SUM) /* deprecated: AUDIT_VERSION_* */ #define AUDIT_VERSION_LATEST AUDIT_FEATURE_BITMAP_ALL #define AUDIT_VERSION_BACKLOG_LIMIT AUDIT_FEATURE_BITMAP_BACKLOG_LIMIT #define AUDIT_VERSION_BACKLOG_WAIT_TIME AUDIT_FEATURE_BITMAP_BACKLOG_WAIT_TIME +#define AUDIT_VERSION_BACKLOG_WAIT_SUM AUDIT_FEATURE_BITMAP_BACKLOG_WAIT_SUM /* Failure-to-log actions */ #define AUDIT_FAIL_SILENT 0 @@ -466,6 +470,7 @@ struct audit_status { __u32 feature_bitmap; /* bitmap of kernel audit features */ }; __u32 backlog_wait_time;/* message queue wait timeout */ + __u32 backlog_wait_sum;/* time spent waiting while message limit exceeded */ }; struct audit_features { diff --git a/kernel/audit.c b/kernel/audit.c index 87f31bf1f0a0..301ea4f3d750 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -136,6 +136,11 @@ u32 audit_sig_sid = 0; */ static atomic_t audit_lost = ATOMIC_INIT(0); +/* Monotonically increasing sum of time the kernel has spent + * waiting while the backlog limit is exceeded. + */ +static atomic_t audit_backlog_wait_sum = ATOMIC_INIT(0); + /* Hash for inode-based rules */ struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS]; @@ -1204,6 +1209,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) s.backlog = skb_queue_len(&audit_queue); s.feature_bitmap = AUDIT_FEATURE_BITMAP_ALL; s.backlog_wait_time = audit_backlog_wait_time; + s.backlog_wait_sum = atomic_read(&audit_backlog_wait_sum); audit_send_reply(skb, seq, AUDIT_GET, 0, 0, &s, sizeof(s)); break; } @@ -1794,6 +1800,9 @@ struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, return NULL; } } + + if (stime != audit_backlog_wait_time) + atomic_add(audit_backlog_wait_time - stime, &audit_backlog_wait_sum); } ab = audit_buffer_alloc(ctx, gfp_mask, type); -- 2.17.1

4 years

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New release?

by Laurent Bigonville

Hello, The freeze of the new debian release is approaching (early next year) and I'm looking a bit for guidance about what do with the audit package. Should I start cherry-picking patches, wait for a new (pre-)release? Keep the good 2.8? Kind regards, Laurent Bigonville

4 years

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auditd for removable media/harddisks

by foo＠mailbox.org

Hi, I want to track file writes on a removable harddisk: $ mount ... /dev/sda9 on /mnt/volatile_folder type ext4 (rw) ... $ cat /etc/audit/audit.rules ... -w /mnt/volatile_folder -p w -k folder ... External processes regularly unmount, format and mount /dev/sda9. Currently unmounting the device stops the auditd volatile_folder watcher and I have to restart auditd. Is there a better way? Thx + Best Fir

4 years

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[PATCH] audit: replace atomic_add_return()

by Yejune Deng

atomic_inc_return() is a little neater Signed-off-by: Yejune Deng <yejune.deng(a)gmail.com> --- kernel/audit.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/audit.c b/kernel/audit.c index e22f22b..1ffc2e0 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -1779,7 +1779,7 @@ unsigned int audit_serial(void) { static atomic_t serial = ATOMIC_INIT(0); - return atomic_add_return(1, &serial); + return atomic_inc_return(&serial); } static inline void audit_get_stamp(struct audit_context *ctx, -- 1.9.1

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[PATCH v2 00/39] fs: idmapped mounts

by Christian Brauner

Hey everyone, This is v2. It is reworked according to the reviews coming from Christoph and others to adapt all relevant helpers and inode_operations methods to account for idmapped mounts instead of introducing new helpers and methods specific to idmapped mounts like we did before. We've also moved the overlayfs conversion to handle idmapped mounts into a separate patchset that will be sent out separately after the core changes. The converted filesytems in this series include fat and ext4. The config option to disable idmapped mounts has been moved from a a vfs config ption to a per-filesystem option. They default to off. Having a config option allows us to gain some confidence in the patchset over multiple kernel releases. There are two noteable things about this version. First, that it comes with a really large test-suite to test current vfs behavior and idmapped mounts behavior. We intend this test-suite to grow over time and at some point cover most basic core vfs functionality that isn't covered in xfstests and have it be part of the selftests. Second, while while working on adapting this patchset to the requested changes, the runC and containerd crowd was nice enough to adapt containerd to this patchset to make use of idmapped mounts in one of the most widely used container runtimes: https://github.com/containerd/containerd/pull/4734 With this patchset we make it possible to attach idmappings to bind mounts. This handles several common use-cases. Here are just a few: - Shifting of a container rootfs or base image without having to mangle every file (runc, Docker, containerd, k8s, LXD, systemd ...) - Sharing of data between host or privileged containers with underprivileged containers (runc, Docker, containerd, k8s, LXD, ...) - Shifting of subset of ownership-less filesystems (vfat) for use by multiple users, effectively allowing for DAC on such devices (systemd, Android, ...) - Data sharing between multiple user namespaces with incompatible maps (LXD, k8s, ...) Making it possible to share directories and mounts between users with different uids and gids is itself quite an important use-case in distributed systems environments. It's of course especially useful in general for portable usb sticks, sharing data between multiple users in general, and sharing home directories between multiple users. The last example is now elegantly expressed in systemd's homed concept for portable home directories. As mentioned above, idmapped mounts also allow data from the host to be shared with unprivileged containers, between privileged and unprivileged containers simultaneously and in addition also between unprivileged containers with different idmappings whenever they are used to isolate one container completely from another container. As can be seen from answers to earlier threads of this patchset and from the list of potential users interest in this patchset is fairly widespread. We have implemented and proposed multiple solutions to this before. This included the introduction of fsid mappings, a tiny filesystem that is currently carried in Ubuntu that has shown it's limitations, and an approach to call override creds in the vfs. None of these solutions have covered all of the above use-cases. Some of them have been fairly hacky too by e.g. violating how things should be passed down to the individual filesystems. The solution proposed here has it's origins in multiple discussions during Linux Plumbers 2017 during and after the end of the containers microconference. To the best of my knowledge this involved Aleksa, Stéphane, Eric, David, James, and myself. The original idea or a variant thereof has been discussed, again to the best of my knowledge, after a Linux conference in St. Petersburg in Russia in 2017 between Christoph, Tycho, and myself. We've taken the time to implement a working version of this solution over the last weeks to the best of my abilities. Tycho has signed up for this sligthly crazy endeavour as well and he has helped with the conversion of the xattr codepaths and will be involved with others in converting additional filesystems. This series makes idmappings a property of struct vfsmount instead of tying it to a process being inside of a user namespace which has been the case for all other proposed approaches. It also allows to pass down the user namespace into the filesystms which is a clean way instead of violating calling conventions by strapping the user namespace information that is a property of the mount to the caller's credentials or similar hacks. With this idmappings become a property of bind-mounts, i.e. each bind-mount can have a separate idmapping. Such idmapped mounts can even be created inside of the initial user namespace. The vfsmount struct gains a new struct user_namespace member. The idmapping of the user namespace becomes the idmapping of the mount. A caller that is privileged with respect to the user namespace of the superblock of the underlying filesystem can create an idmapped bind-mount. In the future, we can enable unprivileged use-cases by checking whether the caller is privileged wrt to the user namespace an already idmapped mount has been marked with, allowing them to change the idmapping. For now, keep things simple until we feel sure enough. Note, that with syscall interception it is already possible to intercept idmapped mount requests from unprivileged containers and handle them in a sufficiently privileged container manager. Support for this is already available in LXD and will be available in runC were syscall interception is currently becoming part of the runtime spec (see https://github.com/opencontainers/runtime-spec/pull/1074). The user namespace the mount will be marked with can be specified by passing a file descriptor refering to the user namespace as an argument to the new mount_setattr() syscall together with the new MOUNT_ATTR_IDMAP flag. By default vfsmounts are marked with the initial user namespace and no behavioral or performance changes should be observed. All mapping operations are nops for the initial user namespace. When a file/inode is accessed through an idmapped mount the i_uid and i_gid of the inode will be remapped according to the user namespace the mount has been marked with. In order to support idmapped mounts, filesystems need to be changed and mark themselves with the FS_ALLOW_IDMAP flag in fs_flags. The initial version contains fat and ext4 including a list of examples. But patches for other filesystems are actively worked on but will be sent out separately. We are here to see this through and there are multiple people involved in converting filesystems. So filesystem developers are not left alone with this. I have written a simple tool available at https://github.com/brauner/mount-idmapped that allows to create idmapped mounts so people can play with this patch series. Here are a few illustrations: 1. Create a simple idmapped mount of another user's home directory u1001@f2-vm:/$ sudo ./mount-idmapped --map-mount b:1000:1001:1 /home/ubuntu/ /mnt u1001@f2-vm:/$ ls -al /home/ubuntu/ total 28 drwxr-xr-x 2 ubuntu ubuntu 4096 Oct 28 22:07 . drwxr-xr-x 4 root root 4096 Oct 28 04:00 .. -rw------- 1 ubuntu ubuntu 3154 Oct 28 22:12 .bash_history -rw-r--r-- 1 ubuntu ubuntu 220 Feb 25 2020 .bash_logout -rw-r--r-- 1 ubuntu ubuntu 3771 Feb 25 2020 .bashrc -rw-r--r-- 1 ubuntu ubuntu 807 Feb 25 2020 .profile -rw-r--r-- 1 ubuntu ubuntu 0 Oct 16 16:11 .sudo_as_admin_successful -rw------- 1 ubuntu ubuntu 1144 Oct 28 00:43 .viminfo u1001@f2-vm:/$ ls -al /mnt/ total 28 drwxr-xr-x 2 u1001 u1001 4096 Oct 28 22:07 . drwxr-xr-x 29 root root 4096 Oct 28 22:01 .. -rw------- 1 u1001 u1001 3154 Oct 28 22:12 .bash_history -rw-r--r-- 1 u1001 u1001 220 Feb 25 2020 .bash_logout -rw-r--r-- 1 u1001 u1001 3771 Feb 25 2020 .bashrc -rw-r--r-- 1 u1001 u1001 807 Feb 25 2020 .profile -rw-r--r-- 1 u1001 u1001 0 Oct 16 16:11 .sudo_as_admin_successful -rw------- 1 u1001 u1001 1144 Oct 28 00:43 .viminfo u1001@f2-vm:/$ touch /mnt/my-file u1001@f2-vm:/$ setfacl -m u:1001:rwx /mnt/my-file u1001@f2-vm:/$ sudo setcap -n 1001 cap_net_raw+ep /mnt/my-file u1001@f2-vm:/$ ls -al /mnt/my-file -rw-rwxr--+ 1 u1001 u1001 0 Oct 28 22:14 /mnt/my-file u1001@f2-vm:/$ ls -al /home/ubuntu/my-file -rw-rwxr--+ 1 ubuntu ubuntu 0 Oct 28 22:14 /home/ubuntu/my-file u1001@f2-vm:/$ getfacl /mnt/my-file getfacl: Removing leading '/' from absolute path names # file: mnt/my-file # owner: u1001 # group: u1001 user::rw- user:u1001:rwx group::rw- mask::rwx other::r-- u1001@f2-vm:/$ getfacl /home/ubuntu/my-file getfacl: Removing leading '/' from absolute path names # file: home/ubuntu/my-file # owner: ubuntu # group: ubuntu user::rw- user:ubuntu:rwx group::rw- mask::rwx other::r-- 2. Create mapping of the whole ext4 rootfs without a mapping for uid and gid 0 ubuntu@f2-vm:~$ sudo /mount-idmapped --map-mount b:1:1:65536 / /mnt/ ubuntu@f2-vm:~$ findmnt | grep mnt └─/mnt /dev/sda2 ext4 rw,relatime └─/mnt/mnt /dev/sda2 ext4 rw,relatime ubuntu@f2-vm:~$ sudo mkdir /AS-ROOT-CAN-CREATE ubuntu@f2-vm:~$ sudo mkdir /mnt/AS-ROOT-CANT-CREATE mkdir: cannot create directory ‘/mnt/AS-ROOT-CANT-CREATE’: Value too large for defined data type ubuntu@f2-vm:~$ mkdir /mnt/home/ubuntu/AS-USER-1000-CAN-CREATE 3. Create a vfat usb mount and expose to user 1001 and 5000 ubuntu@f2-vm:/$ sudo mount /dev/sdb /mnt ubuntu@f2-vm:/$ findmnt | grep mnt └─/mnt /dev/sdb vfat rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro ubuntu@f2-vm:/$ ls -al /mnt total 12 drwxr-xr-x 2 root root 4096 Jan 1 1970 . drwxr-xr-x 34 root root 4096 Oct 28 22:24 .. -rwxr-xr-x 1 root root 4 Oct 28 03:44 aaa -rwxr-xr-x 1 root root 0 Oct 28 01:09 bbb ubuntu@f2-vm:/$ sudo /mount-idmapped --map-mount b:0:1001:1 /mnt /mnt-1001/ ubuntu@f2-vm:/$ ls -al /mnt-1001/ total 12 drwxr-xr-x 2 u1001 u1001 4096 Jan 1 1970 . drwxr-xr-x 34 root root 4096 Oct 28 22:24 .. -rwxr-xr-x 1 u1001 u1001 4 Oct 28 03:44 aaa -rwxr-xr-x 1 u1001 u1001 0 Oct 28 01:09 bbb ubuntu@f2-vm:/$ sudo /mount-idmapped --map-mount b:0:5000:1 /mnt /mnt-5000/ ubuntu@f2-vm:/$ ls -al /mnt-5000/ total 12 drwxr-xr-x 2 5000 5000 4096 Jan 1 1970 . drwxr-xr-x 34 root root 4096 Oct 28 22:24 .. -rwxr-xr-x 1 5000 5000 4 Oct 28 03:44 aaa -rwxr-xr-x 1 5000 5000 0 Oct 28 01:09 bbb 4. Create an idmapped rootfs mount for a container root@f2-vm:~# ls -al /var/lib/lxc/f2/rootfs/ total 68 drwxr-xr-x 17 20000 20000 4096 Sep 24 07:48 . drwxrwx--- 3 20000 20000 4096 Oct 16 19:26 .. lrwxrwxrwx 1 20000 20000 7 Sep 24 07:43 bin -> usr/bin drwxr-xr-x 2 20000 20000 4096 Apr 15 2020 boot drwxr-xr-x 3 20000 20000 4096 Oct 16 19:26 dev drwxr-xr-x 61 20000 20000 4096 Oct 16 19:26 etc drwxr-xr-x 3 20000 20000 4096 Sep 24 07:45 home lrwxrwxrwx 1 20000 20000 7 Sep 24 07:43 lib -> usr/lib lrwxrwxrwx 1 20000 20000 9 Sep 24 07:43 lib32 -> usr/lib32 lrwxrwxrwx 1 20000 20000 9 Sep 24 07:43 lib64 -> usr/lib64 lrwxrwxrwx 1 20000 20000 10 Sep 24 07:43 libx32 -> usr/libx32 drwxr-xr-x 2 20000 20000 4096 Sep 24 07:43 media drwxr-xr-x 2 20000 20000 4096 Sep 24 07:43 mnt drwxr-xr-x 2 20000 20000 4096 Sep 24 07:43 opt drwxr-xr-x 2 20000 20000 4096 Apr 15 2020 proc drwx------ 2 20000 20000 4096 Sep 24 07:43 root drwxr-xr-x 2 20000 20000 4096 Sep 24 07:45 run lrwxrwxrwx 1 20000 20000 8 Sep 24 07:43 sbin -> usr/sbin drwxr-xr-x 2 20000 20000 4096 Sep 24 07:43 srv drwxr-xr-x 2 20000 20000 4096 Apr 15 2020 sys drwxrwxrwt 2 20000 20000 4096 Sep 24 07:44 tmp drwxr-xr-x 13 20000 20000 4096 Sep 24 07:43 usr drwxr-xr-x 12 20000 20000 4096 Sep 24 07:44 var root@f2-vm:~# /mount-idmapped --map-mount b:20000:10000:100000 /var/lib/lxc/f2/rootfs/ /mnt root@f2-vm:~# ls -al /mnt total 68 drwxr-xr-x 17 10000 10000 4096 Sep 24 07:48 . drwxr-xr-x 34 root root 4096 Oct 28 22:24 .. lrwxrwxrwx 1 10000 10000 7 Sep 24 07:43 bin -> usr/bin drwxr-xr-x 2 10000 10000 4096 Apr 15 2020 boot drwxr-xr-x 3 10000 10000 4096 Oct 16 19:26 dev drwxr-xr-x 61 10000 10000 4096 Oct 16 19:26 etc drwxr-xr-x 3 10000 10000 4096 Sep 24 07:45 home lrwxrwxrwx 1 10000 10000 7 Sep 24 07:43 lib -> usr/lib lrwxrwxrwx 1 10000 10000 9 Sep 24 07:43 lib32 -> usr/lib32 lrwxrwxrwx 1 10000 10000 9 Sep 24 07:43 lib64 -> usr/lib64 lrwxrwxrwx 1 10000 10000 10 Sep 24 07:43 libx32 -> usr/libx32 drwxr-xr-x 2 10000 10000 4096 Sep 24 07:43 media drwxr-xr-x 2 10000 10000 4096 Sep 24 07:43 mnt drwxr-xr-x 2 10000 10000 4096 Sep 24 07:43 opt drwxr-xr-x 2 10000 10000 4096 Apr 15 2020 proc drwx------ 2 10000 10000 4096 Sep 24 07:43 root drwxr-xr-x 2 10000 10000 4096 Sep 24 07:45 run lrwxrwxrwx 1 10000 10000 8 Sep 24 07:43 sbin -> usr/sbin drwxr-xr-x 2 10000 10000 4096 Sep 24 07:43 srv drwxr-xr-x 2 10000 10000 4096 Apr 15 2020 sys drwxrwxrwt 2 10000 10000 4096 Sep 24 07:44 tmp drwxr-xr-x 13 10000 10000 4096 Sep 24 07:43 usr drwxr-xr-x 12 10000 10000 4096 Sep 24 07:44 var root@f2-vm:~# lxc-start f2 # uses /mnt as rootfs root@f2-vm:~# lxc-attach f2 -- cat /proc/1/uid_map 0 10000 10000 root@f2-vm:~# lxc-attach f2 -- cat /proc/1/gid_map 0 10000 10000 root@f2-vm:~# lxc-attach f2 -- ls -al / total 52 drwxr-xr-x 17 root root 4096 Sep 24 07:48 . drwxr-xr-x 17 root root 4096 Sep 24 07:48 .. lrwxrwxrwx 1 root root 7 Sep 24 07:43 bin -> usr/bin drwxr-xr-x 2 root root 4096 Apr 15 2020 boot drwxr-xr-x 5 root root 500 Oct 28 23:39 dev drwxr-xr-x 61 root root 4096 Oct 28 23:39 etc drwxr-xr-x 3 root root 4096 Sep 24 07:45 home lrwxrwxrwx 1 root root 7 Sep 24 07:43 lib -> usr/lib lrwxrwxrwx 1 root root 9 Sep 24 07:43 lib32 -> usr/lib32 lrwxrwxrwx 1 root root 9 Sep 24 07:43 lib64 -> usr/lib64 lrwxrwxrwx 1 root root 10 Sep 24 07:43 libx32 -> usr/libx32 drwxr-xr-x 2 root root 4096 Sep 24 07:43 media drwxr-xr-x 2 root root 4096 Sep 24 07:43 mnt drwxr-xr-x 2 root root 4096 Sep 24 07:43 opt dr-xr-xr-x 232 nobody nogroup 0 Oct 28 23:39 proc drwx------ 2 root root 4096 Oct 28 23:41 root drwxr-xr-x 12 root root 360 Oct 28 23:39 run lrwxrwxrwx 1 root root 8 Sep 24 07:43 sbin -> usr/sbin drwxr-xr-x 2 root root 4096 Sep 24 07:43 srv dr-xr-xr-x 13 nobody nogroup 0 Oct 28 23:39 sys drwxrwxrwt 11 root root 4096 Oct 28 23:40 tmp drwxr-xr-x 13 root root 4096 Sep 24 07:43 usr drwxr-xr-x 12 root root 4096 Sep 24 07:44 var root@f2-vm:~# lxc-attach f2 -- ls -al /my-file -rw-r--r-- 1 root root 0 Oct 28 23:43 /my-file root@f2-vm:~# ls -al /var/lib/lxc/f2/rootfs/my-file -rw-r--r-- 1 20000 20000 0 Oct 28 23:43 /var/lib/lxc/f2/rootfs/my-file I'd like to say thanks to: Al for pointing me into the direction to avoid inode alias issues during lookup. David for various discussions around this. Christoph for proving a first proper review and for being involved in the original idea. Tycho for helping with this series and on future patches to convert filesystems. Alban Crequy and the Kinvolk located just a few streets away from me in Berlin for providing use-case discussions and writing patches for containerd! Stéphane for his invaluable input on many things and level head and enabling me to work on this. Amir for explaining and discussing aspects of overlayfs with me. I'd like to especially thank Seth Forshee because he provided a lot of good analysis, suggestions, and participated in short-notice discussions in both chat and video for some nitty-gritty technical details. This series can be found and pulled from the three usual locations: https://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux.git/log/?h=... https://github.com/brauner/linux/tree/idmapped_mounts https://gitlab.com/brauner/linux/-/commits/idmapped_mounts Thanks! Christian Christian Brauner (37): namespace: take lock_mount_hash() directly when changing flags mount: make {lock,unlock}_mount_hash() static namespace: only take read lock in do_reconfigure_mnt() fs: add mount_setattr() tests: add mount_setattr() selftests fs: add id translation helpers mount: attach mappings to mounts capability: handle idmapped mounts namei: add idmapped mount aware permission helpers inode: add idmapped mount aware init and permission helpers attr: handle idmapped mounts acl: handle idmapped mounts commoncap: handle idmapped mounts stat: handle idmapped mounts namei: handle idmapped mounts in may_*() helpers namei: introduce struct renamedata namei: prepare for idmapped mounts open: handle idmapped mounts in do_truncate() open: handle idmapped mounts af_unix: handle idmapped mounts utimes: handle idmapped mounts fcntl: handle idmapped mounts notify: handle idmapped mounts init: handle idmapped mounts ioctl: handle idmapped mounts would_dump: handle idmapped mounts exec: handle idmapped mounts fs: add helpers for idmap mounts apparmor: handle idmapped mounts audit: handle idmapped mounts ima: handle idmapped mounts fat: handle idmapped mounts ext4: support idmapped mounts ecryptfs: do not mount on top of idmapped mounts overlayfs: do not mount on top of idmapped mounts fs: introduce MOUNT_ATTR_IDMAP tests: add vfs/idmapped mounts test suite Tycho Andersen (2): xattr: handle idmapped mounts selftests: add idmapped mounts xattr selftest Documentation/filesystems/locking.rst | 6 +- Documentation/filesystems/porting.rst | 2 + Documentation/filesystems/vfs.rst | 17 +- arch/alpha/kernel/syscalls/syscall.tbl | 1 + arch/arm/tools/syscall.tbl | 1 + arch/arm64/include/asm/unistd32.h | 2 + arch/ia64/kernel/syscalls/syscall.tbl | 1 + arch/m68k/kernel/syscalls/syscall.tbl | 1 + arch/microblaze/kernel/syscalls/syscall.tbl | 1 + arch/mips/kernel/syscalls/syscall_n32.tbl | 1 + arch/mips/kernel/syscalls/syscall_n64.tbl | 1 + arch/mips/kernel/syscalls/syscall_o32.tbl | 1 + arch/parisc/kernel/syscalls/syscall.tbl | 1 + arch/powerpc/kernel/syscalls/syscall.tbl | 1 + arch/powerpc/platforms/cell/spufs/inode.c | 5 +- arch/s390/kernel/syscalls/syscall.tbl | 1 + arch/sh/kernel/syscalls/syscall.tbl | 1 + arch/sparc/kernel/syscalls/syscall.tbl | 1 + arch/x86/entry/syscalls/syscall_32.tbl | 1 + arch/x86/entry/syscalls/syscall_64.tbl | 1 + arch/xtensa/kernel/syscalls/syscall.tbl | 1 + drivers/android/binderfs.c | 3 +- drivers/base/devtmpfs.c | 12 +- fs/9p/acl.c | 7 +- fs/9p/v9fs.h | 3 +- fs/9p/v9fs_vfs.h | 2 +- fs/9p/vfs_inode.c | 32 +- fs/9p/vfs_inode_dotl.c | 34 +- fs/9p/xattr.c | 1 + fs/adfs/adfs.h | 3 +- fs/adfs/inode.c | 5 +- fs/affs/affs.h | 10 +- fs/affs/inode.c | 7 +- fs/affs/namei.c | 15 +- fs/afs/dir.c | 34 +- fs/afs/inode.c | 5 +- fs/afs/internal.h | 4 +- fs/afs/security.c | 2 +- fs/afs/xattr.c | 2 + fs/attr.c | 78 +- fs/autofs/root.c | 13 +- fs/bad_inode.c | 31 +- fs/bfs/dir.c | 12 +- fs/btrfs/acl.c | 5 +- fs/btrfs/ctree.h | 3 +- fs/btrfs/inode.c | 41 +- fs/btrfs/ioctl.c | 25 +- fs/btrfs/tests/btrfs-tests.c | 2 +- fs/btrfs/xattr.c | 2 + fs/cachefiles/interface.c | 4 +- fs/cachefiles/namei.c | 19 +- fs/cachefiles/xattr.c | 16 +- fs/ceph/acl.c | 5 +- fs/ceph/dir.c | 23 +- fs/ceph/inode.c | 13 +- fs/ceph/super.h | 8 +- fs/ceph/xattr.c | 1 + fs/cifs/cifsfs.c | 4 +- fs/cifs/cifsfs.h | 18 +- fs/cifs/dir.c | 8 +- fs/cifs/inode.c | 22 +- fs/cifs/link.c | 3 +- fs/cifs/xattr.c | 1 + fs/coda/coda_linux.h | 4 +- fs/coda/dir.c | 18 +- fs/coda/inode.c | 5 +- fs/coda/pioctl.c | 6 +- fs/configfs/configfs_internal.h | 7 +- fs/configfs/dir.c | 3 +- fs/configfs/inode.c | 5 +- fs/configfs/symlink.c | 5 +- fs/coredump.c | 12 +- fs/crypto/policy.c | 2 +- fs/debugfs/inode.c | 9 +- fs/ecryptfs/crypto.c | 4 +- fs/ecryptfs/inode.c | 74 +- fs/ecryptfs/main.c | 6 + fs/ecryptfs/mmap.c | 4 +- fs/efivarfs/file.c | 2 +- fs/efivarfs/inode.c | 4 +- fs/erofs/inode.c | 2 +- fs/exec.c | 12 +- fs/exfat/exfat_fs.h | 3 +- fs/exfat/file.c | 9 +- fs/exfat/namei.c | 13 +- fs/ext2/acl.c | 5 +- fs/ext2/acl.h | 3 +- fs/ext2/ext2.h | 2 +- fs/ext2/ialloc.c | 2 +- fs/ext2/inode.c | 11 +- fs/ext2/ioctl.c | 6 +- fs/ext2/namei.c | 22 +- fs/ext2/xattr_security.c | 1 + fs/ext2/xattr_trusted.c | 1 + fs/ext2/xattr_user.c | 1 + fs/ext4/Kconfig | 9 + fs/ext4/acl.c | 5 +- fs/ext4/acl.h | 3 +- fs/ext4/ext4.h | 15 +- fs/ext4/ialloc.c | 7 +- fs/ext4/inode.c | 14 +- fs/ext4/ioctl.c | 18 +- fs/ext4/namei.c | 52 +- fs/ext4/super.c | 6 +- fs/ext4/xattr_hurd.c | 1 + fs/ext4/xattr_security.c | 1 + fs/ext4/xattr_trusted.c | 1 + fs/ext4/xattr_user.c | 1 + fs/f2fs/acl.c | 5 +- fs/f2fs/acl.h | 3 +- fs/f2fs/f2fs.h | 3 +- fs/f2fs/file.c | 23 +- fs/f2fs/namei.c | 26 +- fs/f2fs/xattr.c | 4 +- fs/fat/fat.h | 3 +- fs/fat/file.c | 20 +- fs/fat/namei_msdos.c | 15 +- fs/fat/namei_vfat.c | 15 +- fs/fcntl.c | 3 +- fs/fuse/acl.c | 3 +- fs/fuse/dir.c | 41 +- fs/fuse/fuse_i.h | 4 +- fs/fuse/xattr.c | 2 + fs/gfs2/acl.c | 5 +- fs/gfs2/acl.h | 3 +- fs/gfs2/file.c | 4 +- fs/gfs2/inode.c | 54 +- fs/gfs2/inode.h | 2 +- fs/gfs2/xattr.c | 1 + fs/hfs/attr.c | 1 + fs/hfs/dir.c | 13 +- fs/hfs/hfs_fs.h | 2 +- fs/hfs/inode.c | 7 +- fs/hfsplus/dir.c | 25 +- fs/hfsplus/inode.c | 11 +- fs/hfsplus/ioctl.c | 2 +- fs/hfsplus/xattr.c | 1 + fs/hfsplus/xattr_security.c | 1 + fs/hfsplus/xattr_trusted.c | 1 + fs/hfsplus/xattr_user.c | 1 + fs/hostfs/hostfs_kern.c | 31 +- fs/hpfs/hpfs_fn.h | 2 +- fs/hpfs/inode.c | 7 +- fs/hpfs/namei.c | 20 +- fs/hugetlbfs/inode.c | 31 +- fs/init.c | 21 +- fs/inode.c | 38 +- fs/internal.h | 9 + fs/jffs2/acl.c | 5 +- fs/jffs2/acl.h | 3 +- fs/jffs2/dir.c | 32 +- fs/jffs2/fs.c | 7 +- fs/jffs2/os-linux.h | 2 +- fs/jffs2/security.c | 1 + fs/jffs2/xattr_trusted.c | 1 + fs/jffs2/xattr_user.c | 1 + fs/jfs/acl.c | 5 +- fs/jfs/file.c | 9 +- fs/jfs/ioctl.c | 2 +- fs/jfs/jfs_acl.h | 3 +- fs/jfs/jfs_inode.c | 2 +- fs/jfs/jfs_inode.h | 2 +- fs/jfs/namei.c | 21 +- fs/jfs/xattr.c | 2 + fs/kernfs/dir.c | 7 +- fs/kernfs/inode.c | 15 +- fs/kernfs/kernfs-internal.h | 5 +- fs/libfs.c | 20 +- fs/minix/bitmap.c | 2 +- fs/minix/file.c | 7 +- fs/minix/inode.c | 2 +- fs/minix/namei.c | 25 +- fs/mount.h | 10 - fs/namei.c | 317 +- fs/namespace.c | 473 ++- fs/nfs/dir.c | 23 +- fs/nfs/inode.c | 5 +- fs/nfs/internal.h | 10 +- fs/nfs/namespace.c | 7 +- fs/nfs/nfs3_fs.h | 3 +- fs/nfs/nfs3acl.c | 3 +- fs/nfs/nfs4proc.c | 3 + fs/nfsd/nfs2acl.c | 4 +- fs/nfsd/nfs3acl.c | 4 +- fs/nfsd/nfs4acl.c | 4 +- fs/nfsd/nfs4recover.c | 6 +- fs/nfsd/nfsfh.c | 2 +- fs/nfsd/nfsproc.c | 2 +- fs/nfsd/vfs.c | 47 +- fs/nilfs2/inode.c | 13 +- fs/nilfs2/ioctl.c | 2 +- fs/nilfs2/namei.c | 20 +- fs/nilfs2/nilfs.h | 4 +- fs/notify/fanotify/fanotify_user.c | 2 +- fs/notify/inotify/inotify_user.c | 3 +- fs/ntfs/inode.c | 2 +- fs/ocfs2/acl.c | 5 +- fs/ocfs2/acl.h | 3 +- fs/ocfs2/dlmfs/dlmfs.c | 17 +- fs/ocfs2/file.c | 13 +- fs/ocfs2/file.h | 5 +- fs/ocfs2/ioctl.c | 2 +- fs/ocfs2/namei.c | 21 +- fs/ocfs2/refcounttree.c | 4 +- fs/ocfs2/xattr.c | 3 + fs/omfs/dir.c | 13 +- fs/omfs/file.c | 7 +- fs/omfs/inode.c | 2 +- fs/open.c | 52 +- fs/orangefs/acl.c | 5 +- fs/orangefs/inode.c | 15 +- fs/orangefs/namei.c | 12 +- fs/orangefs/orangefs-kernel.h | 7 +- fs/orangefs/xattr.c | 1 + fs/overlayfs/copy_up.c | 20 +- fs/overlayfs/dir.c | 31 +- fs/overlayfs/file.c | 6 +- fs/overlayfs/inode.c | 21 +- fs/overlayfs/overlayfs.h | 40 +- fs/overlayfs/super.c | 27 +- fs/overlayfs/util.c | 4 +- fs/posix_acl.c | 78 +- fs/proc/base.c | 24 +- fs/proc/fd.c | 4 +- fs/proc/fd.h | 3 +- fs/proc/generic.c | 9 +- fs/proc/internal.h | 2 +- fs/proc/proc_net.c | 2 +- fs/proc/proc_sysctl.c | 12 +- fs/proc/root.c | 2 +- fs/proc_namespace.c | 1 + fs/ramfs/file-nommu.c | 9 +- fs/ramfs/inode.c | 18 +- fs/reiserfs/acl.h | 3 +- fs/reiserfs/inode.c | 7 +- fs/reiserfs/ioctl.c | 4 +- fs/reiserfs/namei.c | 21 +- fs/reiserfs/reiserfs.h | 3 +- fs/reiserfs/xattr.c | 12 +- fs/reiserfs/xattr.h | 2 +- fs/reiserfs/xattr_acl.c | 7 +- fs/reiserfs/xattr_security.c | 3 +- fs/reiserfs/xattr_trusted.c | 3 +- fs/reiserfs/xattr_user.c | 3 +- fs/remap_range.c | 7 +- fs/stat.c | 10 +- fs/sysv/file.c | 7 +- fs/sysv/ialloc.c | 2 +- fs/sysv/itree.c | 2 +- fs/sysv/namei.c | 21 +- fs/tracefs/inode.c | 4 +- fs/ubifs/dir.c | 29 +- fs/ubifs/file.c | 5 +- fs/ubifs/ioctl.c | 2 +- fs/ubifs/ubifs.h | 3 +- fs/ubifs/xattr.c | 1 + fs/udf/file.c | 9 +- fs/udf/ialloc.c | 2 +- fs/udf/namei.c | 24 +- fs/udf/symlink.c | 2 +- fs/ufs/ialloc.c | 2 +- fs/ufs/inode.c | 7 +- fs/ufs/namei.c | 19 +- fs/ufs/ufs.h | 3 +- fs/utimes.c | 4 +- fs/vboxsf/dir.c | 12 +- fs/vboxsf/utils.c | 5 +- fs/vboxsf/vfsmod.h | 3 +- fs/verity/enable.c | 2 +- fs/xattr.c | 136 +- fs/xfs/xfs_acl.c | 5 +- fs/xfs/xfs_acl.h | 3 +- fs/xfs/xfs_ioctl.c | 4 +- fs/xfs/xfs_iops.c | 55 +- fs/xfs/xfs_xattr.c | 3 +- fs/zonefs/super.c | 9 +- include/linux/audit.h | 10 +- include/linux/capability.h | 14 +- include/linux/fs.h | 145 +- include/linux/ima.h | 15 +- include/linux/lsm_hook_defs.h | 15 +- include/linux/lsm_hooks.h | 1 + include/linux/mount.h | 14 +- include/linux/nfs_fs.h | 4 +- include/linux/posix_acl.h | 15 +- include/linux/posix_acl_xattr.h | 12 +- include/linux/security.h | 44 +- include/linux/syscalls.h | 3 + include/linux/xattr.h | 30 +- include/uapi/asm-generic/unistd.h | 4 +- include/uapi/linux/mount.h | 25 + ipc/mqueue.c | 16 +- kernel/auditsc.c | 29 +- kernel/bpf/inode.c | 13 +- kernel/capability.c | 14 +- kernel/cgroup/cgroup.c | 2 +- kernel/sys.c | 2 +- mm/madvise.c | 4 +- mm/memcontrol.c | 2 +- mm/mincore.c | 4 +- mm/shmem.c | 45 +- net/socket.c | 6 +- net/unix/af_unix.c | 4 +- security/apparmor/apparmorfs.c | 3 +- security/apparmor/domain.c | 13 +- security/apparmor/file.c | 5 +- security/apparmor/lsm.c | 12 +- security/commoncap.c | 46 +- security/integrity/evm/evm_crypto.c | 11 +- security/integrity/evm/evm_main.c | 4 +- security/integrity/evm/evm_secfs.c | 2 +- security/integrity/ima/ima.h | 19 +- security/integrity/ima/ima_api.c | 10 +- security/integrity/ima/ima_appraise.c | 22 +- security/integrity/ima/ima_asymmetric_keys.c | 2 +- security/integrity/ima/ima_main.c | 28 +- security/integrity/ima/ima_policy.c | 17 +- security/integrity/ima/ima_queue_keys.c | 2 +- security/security.c | 25 +- security/selinux/hooks.c | 22 +- security/smack/smack_lsm.c | 18 +- tools/include/uapi/asm-generic/unistd.h | 4 +- tools/testing/selftests/Makefile | 1 + .../testing/selftests/idmap_mounts/.gitignore | 2 + tools/testing/selftests/idmap_mounts/Makefile | 12 + tools/testing/selftests/idmap_mounts/config | 1 + tools/testing/selftests/idmap_mounts/core.c | 3476 +++++++++++++++++ .../testing/selftests/idmap_mounts/internal.h | 127 + tools/testing/selftests/idmap_mounts/utils.c | 136 + tools/testing/selftests/idmap_mounts/utils.h | 17 + tools/testing/selftests/idmap_mounts/xattr.c | 172 + .../selftests/mount_setattr/.gitignore | 1 + .../testing/selftests/mount_setattr/Makefile | 7 + tools/testing/selftests/mount_setattr/config | 1 + .../mount_setattr/mount_setattr_test.c | 889 +++++ 335 files changed, 7594 insertions(+), 1570 deletions(-) create mode 100644 tools/testing/selftests/idmap_mounts/.gitignore create mode 100644 tools/testing/selftests/idmap_mounts/Makefile create mode 100644 tools/testing/selftests/idmap_mounts/config create mode 100644 tools/testing/selftests/idmap_mounts/core.c create mode 100644 tools/testing/selftests/idmap_mounts/internal.h create mode 100644 tools/testing/selftests/idmap_mounts/utils.c create mode 100644 tools/testing/selftests/idmap_mounts/utils.h create mode 100644 tools/testing/selftests/idmap_mounts/xattr.c create mode 100644 tools/testing/selftests/mount_setattr/.gitignore create mode 100644 tools/testing/selftests/mount_setattr/Makefile create mode 100644 tools/testing/selftests/mount_setattr/config create mode 100644 tools/testing/selftests/mount_setattr/mount_setattr_test.c base-commit: 3cea11cd5e3b00d91caf0b4730194039b45c5891 -- 2.29.2

4 years

9
60
0 / 0

[PATCH] audit: remove unused macros

by Alex Shi

Some unused macros could cause gcc warning: kernel/audit.c:68:0: warning: macro "AUDIT_UNINITIALIZED" is not used [-Wunused-macros] kernel/auditsc.c:104:0: warning: macro "AUDIT_AUX_IPCPERM" is not used [-Wunused-macros] kernel/auditsc.c:82:0: warning: macro "AUDITSC_INVALID" is not used [-Wunused-macros] remove them to tame gcc. Signed-off-by: Alex Shi <alex.shi(a)linux.alibaba.com> Cc: Paul Moore <paul(a)paul-moore.com> Cc: Eric Paris <eparis(a)redhat.com> Cc: linux-audit(a)redhat.com Cc: linux-kernel(a)vger.kernel.org --- kernel/audit.c | 1 - kernel/auditsc.c | 3 --- 2 files changed, 4 deletions(-) diff --git a/kernel/audit.c b/kernel/audit.c index ac0aeaa99937..dfac1e0ca887 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -65,7 +65,6 @@ /* No auditing will take place until audit_initialized == AUDIT_INITIALIZED. * (Initialization happens after skb_init is called.) */ #define AUDIT_DISABLED -1 -#define AUDIT_UNINITIALIZED 0 #define AUDIT_INITIALIZED 1 static int audit_initialized; diff --git a/kernel/auditsc.c b/kernel/auditsc.c index 183d79cc2e12..eeb4930d499f 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -80,7 +80,6 @@ #include "audit.h" /* flags stating the success for a syscall */ -#define AUDITSC_INVALID 0 #define AUDITSC_SUCCESS 1 #define AUDITSC_FAILURE 2 @@ -102,8 +101,6 @@ struct audit_aux_data { int type; }; -#define AUDIT_AUX_IPCPERM 0 - /* Number of target pids per aux struct. */ #define AUDIT_AUX_PIDS 16 -- 1.8.3.1

4 years

3
7
0 / 0

Identifying thread/process termination

by L. A. Walsh

Repost from right address. On 2020/10/08 08:33, Lenny Bruzenak wrote: > On 10/7/20 7:27 PM, Paul Moore wrote: > > >> Almost everywhere in the kernel we record the TGID for the "pid=" >> values and not the actual task/thread ID. That decision was made >> before my heavy involvement with audit, but my guess is that most >> audit users are focused more on security relevant events at the >> process level, not the thread level. After all, there isn't really >> much in the way of significant boundaries between threads. >> > > That's right, Paul. The process (exe/comm) is the discriminator from a > security perspective. > ---- So, when different threads perform / execute different functionality as loaded by a runtime loadable libraries, how is that discriminated from the initially started program? Often, programs with many threads will rename the threads so they show up differently, though some of those may be processes, on linux there really aren't any threads as being separate from processes -- i.e. threads, at the linux kernel level are built on processes AFAIK. Either way, there can be a separation of what is executed based on what threads are assigned what purposes. I'd be hesitant to label the exe/comm as the only discriminator in an "arbitrary target environment". Certainly it can be in some, but that doesn't mean it has to be sole discriminator when different threads can be mapped to different functions in 1 starting binary. In a similar way, coreutils, can be used as 1 library/binary where functionality is determined by the invoking name. While coreutils uses separate names for each function, there's nothing stopping creating 1 binary with all functions launched in separate threads launched out of some shell performing diverse functions based on a thread ID or name. Certainly it isn't the common case, but it would be a way for a hacker to make their actions more opaque given current limitations. At the same time, it might be the way to create some type of 'all-in-one' shell that could be configured by runtime presence of loadable objects. An audit system supporting appending of arbitrary data types could support appending new data items/types as needed for extension. Such was the Irix audit system that was ported to sgi's linux before the project was cancelled. It had similar benefits to the various layers and protocols that have been added on top of IPv4 networking, with wrappers around the low-level IP layer being added as new protocols demanded. Just saying, a case can be made for needed additions not originally planned -- something that is almost always needed in time.

4 years

2
1
0 / 0

Clarification on log rotation

by Andreas Hasenack

Hi, I'm checking auditd's native logrotation mechanism. The auditd.conf manpage states this for num_logs: "The excess log check is only done on startup and when a reconfigure results in a space check." I kept generating events, and truth be told, no rotation happened once the logfile size was above max_log_file. At least not after a few minutes. When does a space check happens, besides on a restart? Just external events likg SIGUSR1 and perhaps SIGHUP? Since these are external events, how do sysadmins deal with log rotation: completely ignore auditd's native mechanism and setup logrotate as usual?

4 years

2
1
0 / 0

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Linux-audit November 2020