Re: [PATCH 2/2] security/smack implement logging V2
by Casey Schaufler
Etienne Basset wrote:
>> It looks like the only difference between these are their non-logging
>> versions is the logging. I say go ahead and add the auditdata parameter
>> to smk_access and smk_curacc and allow for the case where it is NULL.
>>
>>
> i would prefer keeping a logging and a non-logging variant
> maybe rename smk_access & smk_curacc to smk_access_nolog & smk_curacc_nolog
> Or you really prefer that we pass a NULL when we want the non-logging?
> I guess its a matter of taste, so i let you decide :)
>
I dislike functions that do nothing but set up another function.
>> It would be nice if audit data was only manipulated if audit is
>> installed, but I don't like the idea of ifdeffing everything
>> very much either. How about a static inline in smack.h that is
>> ifdeffed for audit? smack_audit_init? There would need to be one
>> for each field, too.
>>
>>
> why not, but instead of a "initialiser" for each field i'll prefer a macro
> To save some stack we could also conditionnaly define the "common_audit_data"
>
> something like :
>
> #ifdef CONFIG_AUDIT
> #define DEFINE_SMACK_AUDIT_DATA(ad) struct common_audit_data ad
> void smack_audit_init(..) {
> COMMON_AUDIT_DATA_INIT(...)
> }
> #define SMACK_AUDIT_DATA_SET_FIELD(_ad, _field, _value) (_ad._field = _value)
> ...
> #else
> #define DEFINE_SMACK_AUDIT_DATA(ad)
> void smack_audit_init(..)
> {
> }
> #define SMACK_AUDIT_DATA_SET_FIELD(_ad, _field, _value)
> #endif
>
I'm not convinced. #defines are good for assigning names to constants,
but I saw the original Bourne shell code, where defines were used to
make the code look like ALGOL68, so you have to overcome the fear that
was instilled in me when I was young.
>> Now this is tricky. You'll get an audit record for single-label
>> hosts, but not for those that use CIPSO. The former is good, the
>> latter is bad.
>>
>>
> gargll you're right
>
I love those french idioms.
Actually, I don't think there's much point in worrying about it.
The audit you do here is correct, and until you can get more subject
information over the wire there isn't much point doing it on the
receiving end.
15 years, 8 months
- 1
- 0
Re: [PATCH 2/2] security/smack implement logging V2
by Casey Schaufler
Etienne Basset wrote:
> the following patch, add logging of Smack security decisions.
> This is of course very useful to understand what your current smack policy does.
> As suggested by Casey, it also now forbids labels with ' or "
>
It occurred to me later that \ should be disallowed as well.
> It introduces a '/smack/logging' switch :
> 0: no logging
> 1: log denied (default)
> 2: log accepted
> 3: log denied&accepted
>
>
>
> Signed-off-by: Etienne Basset <etienne.basset(a)numericable.fr>
> ---
> diff --git a/security/smack/Kconfig b/security/smack/Kconfig
> index 603b087..d83e708 100644
> --- a/security/smack/Kconfig
> +++ b/security/smack/Kconfig
> @@ -1,6 +1,6 @@
> config SECURITY_SMACK
> bool "Simplified Mandatory Access Control Kernel Support"
> - depends on NETLABEL && SECURITY_NETWORK
> + depends on NETLABEL && SECURITY_NETWORK && AUDIT
>
AUDIT can't be required. While MAC does make sense in certain
embedded environments, audit does not.
> default n
> help
> This selects the Simplified Mandatory Access Control Kernel.
> diff --git a/security/smack/smack.h b/security/smack/smack.h
> index 42ef313..4639d56 100644
> --- a/security/smack/smack.h
> +++ b/security/smack/smack.h
> @@ -20,6 +20,7 @@
> #include <net/netlabel.h>
> #include <linux/list.h>
> #include <linux/rculist.h>
> +#include <linux/lsm_audit.h>
>
> /*
> * Why 23? CIPSO is constrained to 30, so a 32 byte buffer is
> @@ -179,6 +180,11 @@ struct smack_known {
> #define MAY_NOT 0
>
> /*
> + * Number of access types used by Smack (rwxa)
> + */
> +#define SMK_NUM_ACCESS_TYPE 4
> +
> +/*
> * These functions are in smack_lsm.c
> */
> struct inode_smack *new_inode_smack(char *);
> @@ -237,4 +243,22 @@ static inline char *smk_of_inode(const struct inode *isp)
> return sip->smk_inode;
> }
>
> +/*
> + * logging functions
> + */
> +struct smack_log_policy {
> + int log_accepted;
> + int log_denied;
> +};
>
Use bits in a integer rather than a pair of integers unless you
are anticipating using multiple values for them.
> +
> +extern struct smack_log_policy log_policy;
> +
> +void smack_log(char *subject_label, char *object_label,
> + int request,
> + int result, struct common_audit_data *auditdata);
> +
> +int smk_access_log(char *subjectlabel, char *olabel, int access,
> + struct common_audit_data *a);
> +int smk_curacc_log(char *olabel, int access, struct common_audit_data *a);
>
It looks like the only difference between these are their non-logging
versions is the logging. I say go ahead and add the auditdata parameter
to smk_access and smk_curacc and allow for the case where it is NULL.
> +
> #endif /* _SECURITY_SMACK_H */
> diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c
> index ac0a270..2da8a40 100644
> --- a/security/smack/smack_access.c
> +++ b/security/smack/smack_access.c
> @@ -13,6 +13,7 @@
> #include <linux/types.h>
> #include <linux/fs.h>
> #include <linux/sched.h>
> +
>
Remove the empty line.
> #include "smack.h"
>
> struct smack_known smack_known_huh = {
> @@ -59,6 +60,14 @@ LIST_HEAD(smack_known_list);
> */
> static u32 smack_next_secid = 10;
>
> +/* what events do we log
> + * can be overwriten at run-time by /smack/logging
> + */
> +struct smack_log_policy log_policy = {
> + .log_accepted = 0,
> + .log_denied = 1
> +};
> +
>
As I mentioned before, log_policy should be an integer with
bits defined for accepted and denied logging.
> /**
> * smk_access - determine if a subject has a specific access to an object
> * @subject_label: a pointer to the subject's Smack label
> @@ -185,6 +194,129 @@ int smk_curacc(char *obj_label, u32 mode)
> return rc;
> }
>
> +/**
> + * smack_str_from_perm : helper to transalate an int to a
> + * readable string
> + * @string : the string to fill
> + * @access : the int
> + *
> + **/
> +static inline void smack_str_from_perm(char *string, int access)
> +{
> + int i = 0;
> + if (access & MAY_READ)
> + string[i++] = 'r';
> + if (access & MAY_WRITE)
> + string[i++] = 'w';
> + if (access & MAY_EXEC)
> + string[i++] = 'x';
> + if (access & MAY_APPEND)
> + string[i++] = 'a';
> + string[i] = '\0';
> +}
> +
> +/**
> + * smack_log_callback - SMACK specific information
> + * will be called by generic audit code
> + * @ab : the audit_buffer
> + * @a : audit_data
> + *
> + */
> +static void smack_log_callback(struct audit_buffer *ab, void *a)
> +{
> + struct common_audit_data *ad = a;
> +#define smack_info lsm_priv.smack_audit_data
>
Create a variable of the right type and assign it rather than this define.
> + audit_log_format(ab, "SMACK[%s]: action=%s", ad->function,
> + ad->smack_info.result ? "denied" : "granted");
> + audit_log_format(ab, " subject=");
> + audit_log_untrustedstring(ab, ad->smack_info.subject);
>
I'm not 100% sure, but I think that untrustedstring is unnecessary
with {'"\} disallowed and Smack labels always known to be NULL
terminated strings.
> + audit_log_format(ab, " object=");
> + audit_log_untrustedstring(ab, ad->smack_info.object);
> + audit_log_format(ab, " requested=%s", ad->smack_info.request);
> +#undef smack_info
> +}
> +
> +/**
> + * smack_log - Audit the granting or denial of permissions.
> + * @subject_label : smack label of the requester
> + * @object_label : smack label of the object being accessed
> + * @request: requested permissions
> + * @result: result from smk_access
> + * @a: auxiliary audit data
> + *
> + * Audit the granting or denial of permissions in accordance
> + * with the policy.
> + **/
> +void smack_log(char *subject_label, char *object_label, int request,
> + int result, struct common_audit_data *a)
> +{
> + char request_buffer[SMK_NUM_ACCESS_TYPE + 1];
> + u32 denied;
> + u32 audited = 0;
> +
> + /* check if we have to log the current event */
> + if (result != 0) {
> + denied = 1;
> + if (log_policy.log_denied)
> + audited = 1;
> + } else {
> + denied = 0;
> + if (log_policy.log_accepted)
> + audited = 1;
> + }
> + if (audited == 0)
> + return;
>
if (result == 0 && (log_policy & LOG_ACCEPTED) == 0)
return;
if (result == 1 && (log_policy & LOG_DENIED) == 0)
return;
Cleaner, no?
> +
> + if (a->function == NULL)
> + a->function = "unknown";
> +
> +#define smack_info lsm_priv.smack_audit_data
>
Use a variable instead of the define.
> + /* end preparing the audit data */
> + smack_str_from_perm(request_buffer, request);
> + a->smack_info.subject = subject_label;
> + a->smack_info.object = object_label;
> + a->smack_info.request = request_buffer;
> + a->smack_info.result = result;
> + a->lsm_pre_audit = smack_log_callback;
> +
> + common_lsm_audit(a);
> +#undef smack_info
> +}
> +
> +/**
> + * smk_curracc_log : check access of current on olabel
> + * @olabel : label being accessed
> + * @access : access requested
> + * @a : pointer to data
> + *
> + * return the same perm return by smk_curacc
> + */
> +int smk_curacc_log(char *olabel, int access, struct common_audit_data *a)
> +{
> + int rc;
> + rc = smk_curacc(olabel, access);
> + smack_log(current_security(), olabel, access, rc, a);
> + return rc;
> +}
>
I definitely think that adding the audit data to smk_curacc would work.
> +
> +/**
> + * smk_access_log : check access of slabel on olabel
> + * @slabel : subjet label
> + * @olabel : label being accessed
> + * @access : access requested
> + * @a : pointer to data
> + *
> + * return the same perm return by smk_access
> + */
> +int smk_access_log(char *slabel, char *olabel, int access,
> + struct common_audit_data *a)
> +{
> + int rc;
> + rc = smk_access(slabel, olabel, access);
> + smack_log(slabel, olabel, access, rc, a);
> + return rc;
> +}
> +
>
As above.
> static DEFINE_MUTEX(smack_known_lock);
>
> /**
> @@ -209,7 +341,8 @@ struct smack_known *smk_import_entry(const char *string, int len)
> if (found)
> smack[i] = '\0';
> else if (i >= len || string[i] > '~' || string[i] <= ' ' ||
> - string[i] == '/') {
> + string[i] == '/' || string[i] == '"' ||
> + string[i] == 0x27) {
>
I would prefer '\'' to 0x27, and add a check for '\\' please.
> smack[i] = '\0';
> found = 1;
> } else
> diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
> index 9215149..c1844ed 100644
> --- a/security/smack/smack_lsm.c
> +++ b/security/smack/smack_lsm.c
> @@ -103,14 +103,21 @@ struct inode_smack *new_inode_smack(char *smack)
> static int smack_ptrace_may_access(struct task_struct *ctp, unsigned int mode)
> {
> int rc;
> + struct common_audit_data ad;
>
> rc = cap_ptrace_may_access(ctp, mode);
> if (rc != 0)
> return rc;
>
> + COMMON_AUDIT_DATA_INIT(&ad, TASK);
> + ad.u.tsk = ctp;
>
It would be nice if audit data was only manipulated if audit is
installed, but I don't like the idea of ifdeffing everything
very much either. How about a static inline in smack.h that is
ifdeffed for audit? smack_audit_init? There would need to be one
for each field, too.
Assign the result of current_security() to a variable so
you don't have to call it multiple times. This comment applies
in all instances below.
> + /* we won't log here, because rc can be overriden */
> rc = smk_access(current_security(), task_security(ctp), MAY_READWRITE);
> if (rc != 0 && capable(CAP_MAC_OVERRIDE))
> - return 0;
> + rc = 0;
> +
> + smack_log(current_security(), task_security(ctp),
> + MAY_READWRITE, rc, &ad);
> return rc;
> }
>
> @@ -125,14 +132,21 @@ static int smack_ptrace_may_access(struct task_struct *ctp, unsigned int mode)
> static int smack_ptrace_traceme(struct task_struct *ptp)
> {
> int rc;
> -
> + struct common_audit_data ad;
> rc = cap_ptrace_traceme(ptp);
> if (rc != 0)
> return rc;
>
> + COMMON_AUDIT_DATA_INIT(&ad, TASK);
> + ad.u.tsk = ptp;
> +
> + /* we won't log here, because rc can be overriden */
> rc = smk_access(task_security(ptp), current_security(), MAY_READWRITE);
> if (rc != 0 && has_capability(ptp, CAP_MAC_OVERRIDE))
> - return 0;
> + rc = 0;
> +
> + smack_log(task_security(ptp), current_security(),
> + MAY_READWRITE, rc, &ad);
> return rc;
> }
>
> @@ -327,8 +341,14 @@ static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data)
> static int smack_sb_statfs(struct dentry *dentry)
> {
> struct superblock_smack *sbp = dentry->d_sb->s_security;
> + struct common_audit_data ad;
> + int rc;
>
> - return smk_curacc(sbp->smk_floor, MAY_READ);
> + COMMON_AUDIT_DATA_INIT(&ad, FS);
> + ad.u.fs.path.dentry = dentry;
> +
> + rc = smk_curacc_log(sbp->smk_floor, MAY_READ, &ad);
> + return rc;
> }
>
> /**
> @@ -346,8 +366,12 @@ static int smack_sb_mount(char *dev_name, struct path *path,
> char *type, unsigned long flags, void *data)
> {
> struct superblock_smack *sbp = path->mnt->mnt_sb->s_security;
> + struct common_audit_data ad;
>
> - return smk_curacc(sbp->smk_floor, MAY_WRITE);
> + COMMON_AUDIT_DATA_INIT(&ad, FS);
> + ad.u.fs.path.dentry = path->dentry;
> + ad.u.fs.path.mnt = path->mnt;
> + return smk_curacc_log(sbp->smk_floor, MAY_WRITE, &ad);
> }
>
> /**
> @@ -361,10 +385,14 @@ static int smack_sb_mount(char *dev_name, struct path *path,
> static int smack_sb_umount(struct vfsmount *mnt, int flags)
> {
> struct superblock_smack *sbp;
> + struct common_audit_data ad;
>
> sbp = mnt->mnt_sb->s_security;
> + COMMON_AUDIT_DATA_INIT(&ad, FS);
> + ad.u.fs.path.dentry = mnt->mnt_mountpoint;
> + ad.u.fs.path.mnt = mnt;
>
> - return smk_curacc(sbp->smk_floor, MAY_WRITE);
> + return smk_curacc_log(sbp->smk_floor, MAY_WRITE, &ad);
> }
>
> /*
> @@ -441,15 +469,20 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir,
> static int smack_inode_link(struct dentry *old_dentry, struct inode *dir,
> struct dentry *new_dentry)
> {
> - int rc;
> char *isp;
> + struct common_audit_data ad;
> + int rc;
> +
> + COMMON_AUDIT_DATA_INIT(&ad, FS);
> + ad.u.fs.path.dentry = old_dentry;
>
> isp = smk_of_inode(old_dentry->d_inode);
> - rc = smk_curacc(isp, MAY_WRITE);
> + rc = smk_curacc_log(isp, MAY_WRITE, &ad);
>
> if (rc == 0 && new_dentry->d_inode != NULL) {
> isp = smk_of_inode(new_dentry->d_inode);
> - rc = smk_curacc(isp, MAY_WRITE);
> + ad.u.fs.path.dentry = new_dentry;
> + rc = smk_curacc_log(isp, MAY_WRITE, &ad);
> }
>
> return rc;
> @@ -466,18 +499,24 @@ static int smack_inode_link(struct dentry *old_dentry, struct inode *dir,
> static int smack_inode_unlink(struct inode *dir, struct dentry *dentry)
> {
> struct inode *ip = dentry->d_inode;
> + struct common_audit_data ad;
> int rc;
>
> + COMMON_AUDIT_DATA_INIT(&ad, FS);
> + ad.u.fs.path.dentry = dentry;
> +
> /*
> * You need write access to the thing you're unlinking
> */
> - rc = smk_curacc(smk_of_inode(ip), MAY_WRITE);
> - if (rc == 0)
> + rc = smk_curacc_log(smk_of_inode(ip), MAY_WRITE, &ad);
> + if (rc == 0) {
> /*
> * You also need write access to the containing directory
> */
> - rc = smk_curacc(smk_of_inode(dir), MAY_WRITE);
> -
> + ad.u.fs.path.dentry = NULL;
> + ad.u.fs.inode = dir;
> + rc = smk_curacc_log(smk_of_inode(dir), MAY_WRITE, &ad);
> + }
> return rc;
> }
>
> @@ -491,17 +530,24 @@ static int smack_inode_unlink(struct inode *dir, struct dentry *dentry)
> */
> static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry)
> {
> + struct common_audit_data ad;
> int rc;
>
> + COMMON_AUDIT_DATA_INIT(&ad, FS);
> + ad.u.fs.path.dentry = dentry;
> +
> /*
> * You need write access to the thing you're removing
> */
> - rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE);
> - if (rc == 0)
> + rc = smk_curacc_log(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
> + if (rc == 0) {
> /*
> * You also need write access to the containing directory
> */
> - rc = smk_curacc(smk_of_inode(dir), MAY_WRITE);
> + ad.u.fs.path.dentry = NULL;
> + ad.u.fs.inode = dir;
> + rc = smk_curacc_log(smk_of_inode(dir), MAY_WRITE, &ad);
> + }
>
> return rc;
> }
> @@ -525,15 +571,19 @@ static int smack_inode_rename(struct inode *old_inode,
> {
> int rc;
> char *isp;
> + struct common_audit_data ad;
> +
> + COMMON_AUDIT_DATA_INIT(&ad, FS);
> + ad.u.fs.path.dentry = old_dentry;
>
> isp = smk_of_inode(old_dentry->d_inode);
> - rc = smk_curacc(isp, MAY_READWRITE);
> + rc = smk_curacc_log(isp, MAY_READWRITE, &ad);
>
> if (rc == 0 && new_dentry->d_inode != NULL) {
> isp = smk_of_inode(new_dentry->d_inode);
> - rc = smk_curacc(isp, MAY_READWRITE);
> + ad.u.fs.path.dentry = new_dentry;
> + rc = smk_curacc_log(isp, MAY_READWRITE, &ad);
> }
> -
> return rc;
> }
>
> @@ -548,14 +598,16 @@ static int smack_inode_rename(struct inode *old_inode,
> */
> static int smack_inode_permission(struct inode *inode, int mask)
> {
> + struct common_audit_data ad;
> /*
> * No permission to check. Existence test. Yup, it's there.
> */
> if (mask == 0)
> return 0;
> -
> - return smk_curacc(smk_of_inode(inode), mask);
> -}
> + COMMON_AUDIT_DATA_INIT(&ad, FS);
> + ad.u.fs.inode = inode;
> + return smk_curacc_log(smk_of_inode(inode), mask, &ad);
> + }
>
> /**
> * smack_inode_setattr - Smack check for setting attributes
> @@ -566,13 +618,15 @@ static int smack_inode_permission(struct inode *inode, int mask)
> */
> static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr)
> {
> + struct common_audit_data ad;
> /*
> * Need to allow for clearing the setuid bit.
> */
> if (iattr->ia_valid & ATTR_FORCE)
> return 0;
> -
> - return smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE);
> + COMMON_AUDIT_DATA_INIT(&ad, FS);
> + ad.u.fs.path.dentry = dentry;
> + return smk_curacc_log(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
> }
>
> /**
> @@ -584,7 +638,12 @@ static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr)
> */
> static int smack_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
> {
> - return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ);
> + struct common_audit_data ad;
> +
> + COMMON_AUDIT_DATA_INIT(&ad, FS);
> + ad.u.fs.path.dentry = dentry;
> + ad.u.fs.path.mnt = mnt;
> + return smk_curacc_log(smk_of_inode(dentry->d_inode), MAY_READ, &ad);
> }
>
> /**
> @@ -602,6 +661,7 @@ static int smack_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
> static int smack_inode_setxattr(struct dentry *dentry, const char *name,
> const void *value, size_t size, int flags)
> {
> + struct common_audit_data ad;
> int rc = 0;
>
> if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
> @@ -615,8 +675,11 @@ static int smack_inode_setxattr(struct dentry *dentry, const char *name,
> } else
> rc = cap_inode_setxattr(dentry, name, value, size, flags);
>
> + COMMON_AUDIT_DATA_INIT(&ad, FS);
> + ad.u.fs.path.dentry = dentry;
> if (rc == 0)
> - rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE);
> + rc = smk_curacc_log(smk_of_inode(dentry->d_inode),
> + MAY_WRITE, &ad);
>
> return rc;
> }
> @@ -671,7 +734,11 @@ static void smack_inode_post_setxattr(struct dentry *dentry, const char *name,
> */
> static int smack_inode_getxattr(struct dentry *dentry, const char *name)
> {
> - return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ);
> + struct common_audit_data ad;
> +
> + COMMON_AUDIT_DATA_INIT(&ad, FS);
> + ad.u.fs.path.dentry = dentry;
> + return smk_curacc_log(smk_of_inode(dentry->d_inode), MAY_READ, &ad);
> }
>
> /*
> @@ -685,6 +752,7 @@ static int smack_inode_getxattr(struct dentry *dentry, const char *name)
> */
> static int smack_inode_removexattr(struct dentry *dentry, const char *name)
> {
> + struct common_audit_data ad;
> int rc = 0;
>
> if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
> @@ -695,8 +763,11 @@ static int smack_inode_removexattr(struct dentry *dentry, const char *name)
> } else
> rc = cap_inode_removexattr(dentry, name);
>
> + COMMON_AUDIT_DATA_INIT(&ad, FS);
> + ad.u.fs.path.dentry = dentry;
> if (rc == 0)
> - rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE);
> + rc = smk_curacc_log(smk_of_inode(dentry->d_inode),
> + MAY_WRITE, &ad);
>
> return rc;
> }
> @@ -855,12 +926,16 @@ static int smack_file_ioctl(struct file *file, unsigned int cmd,
> unsigned long arg)
> {
> int rc = 0;
> + struct common_audit_data ad;
> +
> + COMMON_AUDIT_DATA_INIT(&ad, FS);
> + ad.u.fs.path = file->f_path;
>
> if (_IOC_DIR(cmd) & _IOC_WRITE)
> - rc = smk_curacc(file->f_security, MAY_WRITE);
> + rc = smk_curacc_log(file->f_security, MAY_WRITE, &ad);
>
> if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ))
> - rc = smk_curacc(file->f_security, MAY_READ);
> + rc = smk_curacc_log(file->f_security, MAY_READ, &ad);
>
> return rc;
> }
> @@ -874,7 +949,11 @@ static int smack_file_ioctl(struct file *file, unsigned int cmd,
> */
> static int smack_file_lock(struct file *file, unsigned int cmd)
> {
> - return smk_curacc(file->f_security, MAY_WRITE);
> + struct common_audit_data ad;
> +
> + COMMON_AUDIT_DATA_INIT(&ad, FS);
> + ad.u.fs.path.dentry = file->f_path.dentry;
> + return smk_curacc_log(file->f_security, MAY_WRITE, &ad);
> }
>
> /**
> @@ -888,8 +967,12 @@ static int smack_file_lock(struct file *file, unsigned int cmd)
> static int smack_file_fcntl(struct file *file, unsigned int cmd,
> unsigned long arg)
> {
> + struct common_audit_data ad;
> int rc;
>
> + COMMON_AUDIT_DATA_INIT(&ad, FS);
> + ad.u.fs.path = file->f_path;
> +
> switch (cmd) {
> case F_DUPFD:
> case F_GETFD:
> @@ -897,7 +980,7 @@ static int smack_file_fcntl(struct file *file, unsigned int cmd,
> case F_GETLK:
> case F_GETOWN:
> case F_GETSIG:
> - rc = smk_curacc(file->f_security, MAY_READ);
> + rc = smk_curacc_log(file->f_security, MAY_READ, &ad);
> break;
> case F_SETFD:
> case F_SETFL:
> @@ -905,10 +988,10 @@ static int smack_file_fcntl(struct file *file, unsigned int cmd,
> case F_SETLKW:
> case F_SETOWN:
> case F_SETSIG:
> - rc = smk_curacc(file->f_security, MAY_WRITE);
> + rc = smk_curacc_log(file->f_security, MAY_WRITE, &ad);
> break;
> default:
> - rc = smk_curacc(file->f_security, MAY_READWRITE);
> + rc = smk_curacc_log(file->f_security, MAY_READWRITE, &ad);
> }
>
> return rc;
> @@ -943,14 +1026,20 @@ static int smack_file_send_sigiotask(struct task_struct *tsk,
> {
> struct file *file;
> int rc;
> + struct common_audit_data ad;
>
> /*
> * struct fown_struct is never outside the context of a struct file
> */
> file = container_of(fown, struct file, f_owner);
> + /* we don't log here as rc can be overriden */
> rc = smk_access(file->f_security, tsk->cred->security, MAY_WRITE);
> if (rc != 0 && has_capability(tsk, CAP_MAC_OVERRIDE))
> return 0;
> +
> + COMMON_AUDIT_DATA_INIT(&ad, TASK);
> + ad.u.tsk = tsk;
> + smack_log(file->f_security, tsk->cred->security, MAY_WRITE, rc, &ad);
> return rc;
> }
>
> @@ -963,7 +1052,10 @@ static int smack_file_send_sigiotask(struct task_struct *tsk,
> static int smack_file_receive(struct file *file)
> {
> int may = 0;
> + struct common_audit_data ad;
>
> + COMMON_AUDIT_DATA_INIT(&ad, TASK);
> + ad.u.fs.path = file->f_path;
> /*
> * This code relies on bitmasks.
> */
> @@ -972,7 +1064,7 @@ static int smack_file_receive(struct file *file)
> if (file->f_mode & FMODE_WRITE)
> may |= MAY_WRITE;
>
> - return smk_curacc(file->f_security, may);
> + return smk_curacc_log(file->f_security, may, &ad);
> }
>
> /*
> @@ -1052,6 +1144,22 @@ static int smack_kernel_create_files_as(struct cred *new,
> }
>
> /**
> + * smk_curacc_on_task - helper to log task related access
> + * @p: the task object
> + * @access : the access requested
> + *
> + * Return 0 if access is permitted
> + */
> +static int smk_curacc_on_task(struct task_struct *p, int access)
> +{
> + struct common_audit_data ad;
> +
> + COMMON_AUDIT_DATA_INIT(&ad, TASK);
> + ad.u.tsk = p;
> + return smk_curacc_log(task_security(p), access, &ad);
> +}
>
I don't think that this is all that much help, and it adds a
level indirection. Better to do the audit initialization in a
consistent way, even if it is clumsy.
Hum. It does happen a lot. I suppose it's OK.
> +
> +/**
> * smack_task_setpgid - Smack check on setting pgid
> * @p: the task object
> * @pgid: unused
> @@ -1060,7 +1168,7 @@ static int smack_kernel_create_files_as(struct cred *new,
> */
> static int smack_task_setpgid(struct task_struct *p, pid_t pgid)
> {
> - return smk_curacc(task_security(p), MAY_WRITE);
> + return smk_curacc_on_task(p, MAY_WRITE);
> }
>
> /**
> @@ -1071,7 +1179,7 @@ static int smack_task_setpgid(struct task_struct *p, pid_t pgid)
> */
> static int smack_task_getpgid(struct task_struct *p)
> {
> - return smk_curacc(task_security(p), MAY_READ);
> + return smk_curacc_on_task(p, MAY_READ);
> }
>
> /**
> @@ -1082,7 +1190,7 @@ static int smack_task_getpgid(struct task_struct *p)
> */
> static int smack_task_getsid(struct task_struct *p)
> {
> - return smk_curacc(task_security(p), MAY_READ);
> + return smk_curacc_on_task(p, MAY_READ);
> }
>
> /**
> @@ -1110,7 +1218,7 @@ static int smack_task_setnice(struct task_struct *p, int nice)
>
> rc = cap_task_setnice(p, nice);
> if (rc == 0)
> - rc = smk_curacc(task_security(p), MAY_WRITE);
> + rc = smk_curacc_on_task(p, MAY_WRITE);
> return rc;
> }
>
> @@ -1127,7 +1235,7 @@ static int smack_task_setioprio(struct task_struct *p, int ioprio)
>
> rc = cap_task_setioprio(p, ioprio);
> if (rc == 0)
> - rc = smk_curacc(task_security(p), MAY_WRITE);
> + rc = smk_curacc_on_task(p, MAY_WRITE);
> return rc;
> }
>
> @@ -1139,7 +1247,7 @@ static int smack_task_setioprio(struct task_struct *p, int ioprio)
> */
> static int smack_task_getioprio(struct task_struct *p)
> {
> - return smk_curacc(task_security(p), MAY_READ);
> + return smk_curacc_on_task(p, MAY_READ);
> }
>
> /**
> @@ -1157,7 +1265,7 @@ static int smack_task_setscheduler(struct task_struct *p, int policy,
>
> rc = cap_task_setscheduler(p, policy, lp);
> if (rc == 0)
> - rc = smk_curacc(task_security(p), MAY_WRITE);
> + rc = smk_curacc_on_task(p, MAY_WRITE);
> return rc;
> }
>
> @@ -1169,7 +1277,7 @@ static int smack_task_setscheduler(struct task_struct *p, int policy,
> */
> static int smack_task_getscheduler(struct task_struct *p)
> {
> - return smk_curacc(task_security(p), MAY_READ);
> + return smk_curacc_on_task(p, MAY_READ);
> }
>
> /**
> @@ -1180,7 +1288,7 @@ static int smack_task_getscheduler(struct task_struct *p)
> */
> static int smack_task_movememory(struct task_struct *p)
> {
> - return smk_curacc(task_security(p), MAY_WRITE);
> + return smk_curacc_on_task(p, MAY_WRITE);
> }
>
> /**
> @@ -1198,18 +1306,23 @@ static int smack_task_movememory(struct task_struct *p)
> static int smack_task_kill(struct task_struct *p, struct siginfo *info,
> int sig, u32 secid)
> {
> + struct common_audit_data ad;
> +
> + COMMON_AUDIT_DATA_INIT(&ad, TASK);
> + ad.u.tsk = p;
> /*
> * Sending a signal requires that the sender
> * can write the receiver.
> */
> if (secid == 0)
> - return smk_curacc(task_security(p), MAY_WRITE);
> + return smk_curacc_log(task_security(p), MAY_WRITE, &ad);
> /*
> * If the secid isn't 0 we're dealing with some USB IO
> * specific behavior. This is not clean. For one thing
> * we can't take privilege into account.
> */
> - return smk_access(smack_from_secid(secid), task_security(p), MAY_WRITE);
> + return smk_access_log(smack_from_secid(secid), task_security(p),
> + MAY_WRITE, &ad);
> }
>
> /**
> @@ -1220,12 +1333,13 @@ static int smack_task_kill(struct task_struct *p, struct siginfo *info,
> */
> static int smack_task_wait(struct task_struct *p)
> {
> + struct common_audit_data ad;
> int rc;
>
> + /* we don't log here, we can be overriden */
> rc = smk_access(current_security(), task_security(p), MAY_WRITE);
> if (rc == 0)
> - return 0;
> -
> + goto out_log;
> /*
> * Allow the operation to succeed if either task
> * has privilege to perform operations that might
> @@ -1239,7 +1353,11 @@ static int smack_task_wait(struct task_struct *p)
> */
> if (capable(CAP_MAC_OVERRIDE) || has_capability(p, CAP_MAC_OVERRIDE))
> return 0;
>
Did you miss this return, or is this check special?
> -
> + /* we log only if we didn't get overriden */
> + out_log:
> + COMMON_AUDIT_DATA_INIT(&ad, TASK);
> + ad.u.tsk = p;
> + smack_log(current_security(), task_security(p), MAY_WRITE, rc, &ad);
> return rc;
> }
>
> @@ -1455,12 +1573,18 @@ static int smack_netlabel_send(struct sock *sk, struct sockaddr_in *sap)
> int sk_lbl;
> char *hostsp;
> struct socket_smack *ssp = sk->sk_security;
> + struct common_audit_data ad;
>
> rcu_read_lock();
> hostsp = smack_host_label(sap);
> if (hostsp != NULL) {
> sk_lbl = SMACK_UNLABELED_SOCKET;
> - rc = smk_access(ssp->smk_out, hostsp, MAY_WRITE);
> + COMMON_AUDIT_DATA_INIT(&ad, NET);
> + ad.u.net.family = sap->sin_family;
> + ad.u.net.dport = sap->sin_port;
> + ad.u.net.v4info.daddr = sap->sin_addr.s_addr;
> +
> + rc = smk_access_log(ssp->smk_out, hostsp, MAY_WRITE, &ad);
> } else {
> sk_lbl = SMACK_CIPSO_SOCKET;
> rc = 0;
> @@ -1656,6 +1780,23 @@ static void smack_shm_free_security(struct shmid_kernel *shp)
> }
>
Now this is tricky. You'll get an audit record for single-label
hosts, but not for those that use CIPSO. The former is good, the
latter is bad.
>
> /**
> + * smk_curacc_shm : check if current has access on shm
> + * @shp : the object
> + * @access : access requested
> + *
> + * Returns 0 if current has the requested access, error code otherwise
> + */
> +static int smk_curacc_shm(struct shmid_kernel *shp, int access)
> +{
> + char *ssp = smack_of_shm(shp);
> + struct common_audit_data ad;
> +
> + COMMON_AUDIT_DATA_INIT(&ad, IPC);
> + ad.u.ipc_id = shp->shm_perm.id;
> + return smk_curacc_log(ssp, access, &ad);
> +}
> +
> +/**
> * smack_shm_associate - Smack access check for shm
> * @shp: the object
> * @shmflg: access requested
> @@ -1664,11 +1805,10 @@ static void smack_shm_free_security(struct shmid_kernel *shp)
> */
> static int smack_shm_associate(struct shmid_kernel *shp, int shmflg)
> {
> - char *ssp = smack_of_shm(shp);
> int may;
>
> may = smack_flags_to_may(shmflg);
> - return smk_curacc(ssp, may);
> + return smk_curacc_shm(shp, may);
> }
>
> /**
> @@ -1680,7 +1820,6 @@ static int smack_shm_associate(struct shmid_kernel *shp, int shmflg)
> */
> static int smack_shm_shmctl(struct shmid_kernel *shp, int cmd)
> {
> - char *ssp;
> int may;
>
> switch (cmd) {
> @@ -1703,9 +1842,7 @@ static int smack_shm_shmctl(struct shmid_kernel *shp, int cmd)
> default:
> return -EINVAL;
> }
> -
> - ssp = smack_of_shm(shp);
> - return smk_curacc(ssp, may);
> + return smk_curacc_shm(shp, may);
> }
>
> /**
> @@ -1719,11 +1856,10 @@ static int smack_shm_shmctl(struct shmid_kernel *shp, int cmd)
> static int smack_shm_shmat(struct shmid_kernel *shp, char __user *shmaddr,
> int shmflg)
> {
> - char *ssp = smack_of_shm(shp);
> int may;
>
> may = smack_flags_to_may(shmflg);
> - return smk_curacc(ssp, may);
> + return smk_curacc_shm(shp, may);
> }
>
> /**
> @@ -1765,6 +1901,23 @@ static void smack_sem_free_security(struct sem_array *sma)
> }
>
> /**
> + * smk_curacc_sem : check if current has access on sem
> + * @sma : the object
> + * @access : access requested
> + *
> + * Returns 0 if current has the requested access, error code otherwise
> + */
> +static int smk_curacc_sem(struct sem_array *sma, int access)
> +{
> + char *ssp = smack_of_sem(sma);
> + struct common_audit_data ad;
> +
> + COMMON_AUDIT_DATA_INIT(&ad, IPC);
> + ad.u.ipc_id = sma->sem_perm.id;
> + return smk_curacc_log(ssp, access, &ad);
> +}
> +
> +/**
> * smack_sem_associate - Smack access check for sem
> * @sma: the object
> * @semflg: access requested
> @@ -1773,11 +1926,10 @@ static void smack_sem_free_security(struct sem_array *sma)
> */
> static int smack_sem_associate(struct sem_array *sma, int semflg)
> {
> - char *ssp = smack_of_sem(sma);
> int may;
>
> may = smack_flags_to_may(semflg);
> - return smk_curacc(ssp, may);
> + return smk_curacc_sem(sma, may);
> }
>
> /**
> @@ -1789,7 +1941,6 @@ static int smack_sem_associate(struct sem_array *sma, int semflg)
> */
> static int smack_sem_semctl(struct sem_array *sma, int cmd)
> {
> - char *ssp;
> int may;
>
> switch (cmd) {
> @@ -1818,8 +1969,7 @@ static int smack_sem_semctl(struct sem_array *sma, int cmd)
> return -EINVAL;
> }
>
> - ssp = smack_of_sem(sma);
> - return smk_curacc(ssp, may);
> + return smk_curacc_sem(sma, may);
> }
>
> /**
> @@ -1836,9 +1986,7 @@ static int smack_sem_semctl(struct sem_array *sma, int cmd)
> static int smack_sem_semop(struct sem_array *sma, struct sembuf *sops,
> unsigned nsops, int alter)
> {
> - char *ssp = smack_of_sem(sma);
> -
> - return smk_curacc(ssp, MAY_READWRITE);
> + return smk_curacc_sem(sma, MAY_READWRITE);
> }
>
> /**
> @@ -1880,6 +2028,23 @@ static char *smack_of_msq(struct msg_queue *msq)
> }
>
> /**
> + * smk_curacc_msq : helper to check if current has access on msq
> + * @msq : the msq
> + * @access : access requested
> + *
> + * return 0 if current has access, error otherwise
> + */
> +static int smk_curacc_msq(struct msg_queue *msq, int access)
> +{
> + char *msp = smack_of_msq(msq);
> + struct common_audit_data ad;
> +
> + COMMON_AUDIT_DATA_INIT(&ad, IPC);
> + ad.u.ipc_id = msq->q_perm.id;
> + return smk_curacc_log(msp, access, &ad);
> +}
> +
> +/**
> * smack_msg_queue_associate - Smack access check for msg_queue
> * @msq: the object
> * @msqflg: access requested
> @@ -1888,11 +2053,10 @@ static char *smack_of_msq(struct msg_queue *msq)
> */
> static int smack_msg_queue_associate(struct msg_queue *msq, int msqflg)
> {
> - char *msp = smack_of_msq(msq);
> int may;
>
> may = smack_flags_to_may(msqflg);
> - return smk_curacc(msp, may);
> + return smk_curacc_msq(msq, may);
> }
>
> /**
> @@ -1904,7 +2068,6 @@ static int smack_msg_queue_associate(struct msg_queue *msq, int msqflg)
> */
> static int smack_msg_queue_msgctl(struct msg_queue *msq, int cmd)
> {
> - char *msp;
> int may;
>
> switch (cmd) {
> @@ -1926,8 +2089,7 @@ static int smack_msg_queue_msgctl(struct msg_queue *msq, int cmd)
> return -EINVAL;
> }
>
> - msp = smack_of_msq(msq);
> - return smk_curacc(msp, may);
> + return smk_curacc_msq(msq, may);
> }
>
> /**
> @@ -1941,11 +2103,10 @@ static int smack_msg_queue_msgctl(struct msg_queue *msq, int cmd)
> static int smack_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg,
> int msqflg)
> {
> - char *msp = smack_of_msq(msq);
> - int rc;
> + int may;
>
> - rc = smack_flags_to_may(msqflg);
> - return smk_curacc(msp, rc);
> + may = smack_flags_to_may(msqflg);
> + return smk_curacc_msq(msq, may);
> }
>
> /**
> @@ -1961,9 +2122,7 @@ static int smack_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg,
> static int smack_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
> struct task_struct *target, long type, int mode)
> {
> - char *msp = smack_of_msq(msq);
> -
> - return smk_curacc(msp, MAY_READWRITE);
> + return smk_curacc_msq(msq, MAY_READWRITE);
> }
>
> /**
> @@ -1976,10 +2135,13 @@ static int smack_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
> static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag)
> {
> char *isp = ipp->security;
> + struct common_audit_data ad;
> int may;
> + COMMON_AUDIT_DATA_INIT(&ad, IPC);
> + ad.u.ipc_id = ipp->id;
>
> may = smack_flags_to_may(flag);
> - return smk_curacc(isp, may);
> + return smk_curacc_log(isp, may, &ad);
> }
>
> /**
> @@ -2238,8 +2400,12 @@ static int smack_unix_stream_connect(struct socket *sock,
> {
> struct inode *sp = SOCK_INODE(sock);
> struct inode *op = SOCK_INODE(other);
> + struct common_audit_data ad;
>
> - return smk_access(smk_of_inode(sp), smk_of_inode(op), MAY_READWRITE);
> + COMMON_AUDIT_DATA_INIT(&ad, NET);
> + ad.u.net.sk = other->sk;
> + return smk_access_log(smk_of_inode(sp), smk_of_inode(op),
> + MAY_READWRITE, &ad);
> }
>
> /**
> @@ -2254,8 +2420,12 @@ static int smack_unix_may_send(struct socket *sock, struct socket *other)
> {
> struct inode *sp = SOCK_INODE(sock);
> struct inode *op = SOCK_INODE(other);
> + struct common_audit_data ad;
>
> - return smk_access(smk_of_inode(sp), smk_of_inode(op), MAY_WRITE);
> + COMMON_AUDIT_DATA_INIT(&ad, NET);
> + ad.u.net.sk = other->sk;
> + return smk_access_log(smk_of_inode(sp), smk_of_inode(op),
> + MAY_WRITE, &ad);
> }
>
> /**
> @@ -2370,6 +2540,7 @@ static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
> char smack[SMK_LABELLEN];
> char *csp;
> int rc;
> + struct common_audit_data ad;
>
> if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)
> return 0;
> @@ -2388,13 +2559,17 @@ static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
>
> netlbl_secattr_destroy(&secattr);
>
> + COMMON_AUDIT_DATA_INIT(&ad, NET);
> + ad.u.net.family = sk->sk_family;
> + ad.u.net.netif = skb->iif;
> + ipv4_skb_to_auditdata(skb, &ad, NULL);
> /*
> * Receiving a packet requires that the other end
> * be able to write here. Read access is not required.
> * This is the simplist possible security model
> * for networking.
> */
> - rc = smk_access(csp, ssp->smk_in, MAY_WRITE);
> + rc = smk_access_log(csp, ssp->smk_in, MAY_WRITE, &ad);
> if (rc != 0)
> netlbl_skbuff_err(skb, rc, 0);
> return rc;
> @@ -2642,6 +2817,7 @@ static int smack_key_permission(key_ref_t key_ref,
> const struct cred *cred, key_perm_t perm)
> {
> struct key *keyp;
> + struct common_audit_data ad;
>
> keyp = key_ref_to_ptr(key_ref);
> if (keyp == NULL)
> @@ -2657,8 +2833,12 @@ static int smack_key_permission(key_ref_t key_ref,
> */
> if (cred->security == NULL)
> return -EACCES;
> + COMMON_AUDIT_DATA_INIT(&ad, KEY);
> + ad.u.key_struct.key = keyp->serial;
> + ad.u.key_struct.key_desc = keyp->description;
>
> - return smk_access(cred->security, keyp->security, MAY_READWRITE);
> + return smk_access_log(cred->security, keyp->security,
> + MAY_READWRITE, &ad);
> }
> #endif /* CONFIG_KEYS */
>
> diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
> index e03a7e1..f141d31 100644
> --- a/security/smack/smackfs.c
> +++ b/security/smack/smackfs.c
> @@ -41,6 +41,7 @@ enum smk_inos {
> SMK_AMBIENT = 7, /* internet ambient label */
> SMK_NETLBLADDR = 8, /* single label hosts */
> SMK_ONLYCAP = 9, /* the only "capable" label */
> + SMK_LOGGING = 10, /* logging */
> };
>
> /*
> @@ -1192,6 +1193,71 @@ static const struct file_operations smk_onlycap_ops = {
> };
>
> /**
> + * smk_read_logging - read() for /smack/logging
> + * @filp: file pointer, not actually used
> + * @buf: where to put the result
> + * @cn: maximum to send along
> + * @ppos: where to start
> + *
> + * Returns number of bytes read or error code, as appropriate
> + */
> +static ssize_t smk_read_logging(struct file *filp, char __user *buf,
> + size_t count, loff_t *ppos)
> +{
> + char temp[32];
> + ssize_t rc;
> +
> + if (*ppos != 0)
> + return 0;
> +
> + sprintf(temp, "%d\n",
> + log_policy.log_denied + log_policy.log_accepted*2);
> + rc = simple_read_from_buffer(buf, count, ppos, temp, strlen(temp));
> + return rc;
> +}
> +
> +/**
> + * smk_write_logging - write() for /smack/logging
> + * @file: file pointer, not actually used
> + * @buf: where to get the data from
> + * @count: bytes sent
> + * @ppos: where to start
> + *
> + * Returns number of bytes written or error code, as appropriate
> + */
> +static ssize_t smk_write_logging(struct file *file, const char __user *buf,
> + size_t count, loff_t *ppos)
> +{
> + char temp[32];
> + int i;
> +
> + if (!capable(CAP_MAC_ADMIN))
> + return -EPERM;
> +
> + if (count >= sizeof(temp) || count == 0)
> + return -EINVAL;
> +
> + if (copy_from_user(temp, buf, count) != 0)
> + return -EFAULT;
> +
> + temp[count] = '\0';
> +
> + if (sscanf(temp, "%d", &i) != 1)
> + return -EINVAL;
> + if (i < 0 || i > 3)
> + return -EINVAL;
> + log_policy.log_denied = i & 1;
> + log_policy.log_accepted = (i & 2) >> 1 ;
>
Again, bits in a integer.
> + return count;
> +}
> +
> +
> +
> +static const struct file_operations smk_logging_ops = {
> + .read = smk_read_logging,
> + .write = smk_write_logging,
> +};
> +/**
> * smk_fill_super - fill the /smackfs superblock
> * @sb: the empty superblock
> * @data: unused
> @@ -1221,6 +1287,8 @@ static int smk_fill_super(struct super_block *sb, void *data, int silent)
> {"netlabel", &smk_netlbladdr_ops, S_IRUGO|S_IWUSR},
> [SMK_ONLYCAP] =
> {"onlycap", &smk_onlycap_ops, S_IRUGO|S_IWUSR},
> + [SMK_LOGGING] =
> + {"logging", &smk_logging_ops, S_IRUGO|S_IWUSR},
> /* last one */ {""}
> };
>
>
>
>
15 years, 8 months
- 1
- 0
Re: [Fwd: [PATCH][RFC] SMACK : add logging support V1]
by Eric Paris
On Tue, 2009-03-31 at 23:44 +0200, Etienne Basset wrote:
> Eric Paris wrote:
> > On Mon, 2009-03-30 at 20:30 +0200, Etienne Basset wrote:
> >>> I pretty strongly detest %s these days. Using it on the left side of an
> >>> = is ok if you are REALLY careful. Using it on the right makes me
> >>> cringe. Can smack labels have characters which are not ascii letters
> >>> (spaces?)
> >>>
> >> no, smack basically do the same tests when importing smack label than you do
> >> in kernel/audit.c:audit_string_contains_control
> >> except smack allows the '"' character
> >
> > How did you plan to handle a SMACK label with a ' ? Using the audit
> > string functions and being given a label with a " is going to give you
> > the hex output. (which might someday turn into better encoding, but I'm
> > still waiting to see some code to do it better)
> >
> hum, since smack labels cannot have special characters and are limited to length 24,
> maybe we could just do :
> subject=FOO object=BAR
> but it would imply using a "object=%s subject=%s"
>
> or using audit_log_untrustedstring and live with the fact that Labels with '"' will be
> printed in hex (i dont expect '"' to be frequently used in labels.)
Since it can contain a " you may not use %s. Just go with
audit_log_untrustedstring and hope people don't use a "
> > Can I suggest if you write userspace tools to do anything with these
> > audit records that you use libauparse? So if we do make changes, SMACK
> > tools keep working (this is the main problem with changing how SELinux
> > uses audit, the userspace tools don't use libauparse so we can't make
> > changes in just the kernel+library...)
> >
> i can have a look, but my first need is /var/log/messages being pretty obvious to read
The changes to string encoding and we want to do would actually make
records more human readable, so if that's your concern we are good.
But, if you ever make tools that parse the raw audit.log rather than
using libauparse it possible (likely?) they break someday down the line.
Don't forget these are going to show up in /var/log/audit/audit.log if
you have auditd running. They'll show up in dmesg/syslog if not.
Thanks for trying to share code between LSMs!
-Eric
15 years, 8 months
- 2
- 1
[RFC PATCH] audit: Fix possible return value truncation in audit_get_context()
by Paul Moore
The audit subsystem treats syscall return codes as type long, unfortunately
the audit_get_context() function mistakenly converts the return code to an
int type in the parameters which could cause problems on systems where the
sizeof(int) != sizeof(long).
Signed-off-by: Paul Moore <paul.moore(a)hp.com>
---
kernel/auditsc.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 8cbddff..8d76dfc 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -751,7 +751,7 @@ static void audit_set_auditable(struct audit_context *ctx)
static inline struct audit_context *audit_get_context(struct task_struct *tsk,
int return_valid,
- int return_code)
+ long return_code)
{
struct audit_context *context = tsk->audit_context;
15 years, 8 months
- 2
- 1