Linux-audit October 2019

linux-audit@lists.linux-audit.osci.io

17 participants
16 discussions

by Evelyn Mitchell

For my own learning, I'm trying to understand what personality=40000 means. In looking at /uapi/linux/personality.h where the personality types are defined, and manually converting 40000 to hex 0x9C40, it looks to me like the personality is set to enable: ADDR_LIMIT_3GB = 0x8000000 SHORT_INODE = 0x1000000 ADDR_LIMIT_32BIT = 0x0800000 READ_IMPLIES_EXEC = 0x0400000 ADDR_COMPAT_LAYOUT = 0x0200000 MMAP_PAGE_ZERO = 0x0100000 ADDR_NO_RANDOMIZE = 0x0040000 But, this looks unreasonable to me as a set of flags someone would deliberately pick, so I thought I'd ask if I'm interpreting this correctly. Evelyn Mitchell > You may never have seen it before because it appears you now have a > personality other than PER_LINUX for this event. 32-bit binary on 64 > bit? I assume your arch is x86 64 (LE)? > > > type=SYSCALL msg=audit(1571245536.351:43593): arch=c000003e syscall=3 > > *per=40000* success=yes exit=0 a0=5 a1=5 a2=556213b6d6bc a3=7f483b98bcc0 > > items=0 ppid=2653 pid=2655 auid=1000 uid=1000 gid=1000 euid=1000 suid=1000 > > fsuid=1000 egid=1000 sgid=1000 fsgid=1000 tty=pts1 ses=3 comm="gdb" > > exe="/usr/bin/gdb" key=(null) > > > > - RGB > > -- > Richard Guy Briggs <rgb(a)redhat.com> > Sr. S/W Engineer, Kernel Security, Base Operating Systems > Remote, Ottawa, Red Hat Canada > IRC: rgb, SunRaycer > Voice: +1.647.777.2635, Internal: (81) 32635 > > > > ------------------------------

5 years, 2 months

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New field seen in audit.log

by Ankitha Kundhuru

Hi All, I found a new word "per" in some of the records of my audit.log. Any idea of why this happened and what it means ? type=SYSCALL msg=audit(1571245536.351:43593): arch=c000003e syscall=3 *per=40000* success=yes exit=0 a0=5 a1=5 a2=556213b6d6bc a3=7f483b98bcc0 items=0 ppid=2653 pid=2655 auid=1000 uid=1000 gid=1000 euid=1000 suid=1000 fsuid=1000 egid=1000 sgid=1000 fsgid=1000 tty=pts1 ses=3 comm="gdb" exe="/usr/bin/gdb" key=(null) Thank you :) Thanks & Regards, Ankitha Kundhuru

5 years, 2 months

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[PATCH v3] audit: Report suspicious O_CREAT usage

by Kees Cook

This renames the very specific audit_log_link_denied() to audit_log_path_denied() and adds the AUDIT_* type as an argument. This allows for the creation of the new AUDIT_ANOM_CREAT that can be used to report the fifo/regular file creation restrictions that were introduced in commit 30aba6656f61 ("namei: allow restricted O_CREAT of FIFOs and regular files"). Signed-off-by: Kees Cook <keescook(a)chromium.org> --- v3: - retain existing operation names (paul) v2: - fix build failure typo in CONFIG_AUDIT=n case - improve operations naming (paul) --- fs/namei.c | 8 ++++++-- include/linux/audit.h | 5 +++-- include/uapi/linux/audit.h | 1 + kernel/audit.c | 11 ++++++----- 4 files changed, 16 insertions(+), 9 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 671c3c1a3425..2dda552bcf7a 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -925,7 +925,7 @@ static inline int may_follow_link(struct nameidata *nd) return -ECHILD; audit_inode(nd->name, nd->stack[0].link.dentry, 0); - audit_log_link_denied("follow_link"); + audit_log_path_denied(AUDIT_ANOM_LINK, "follow_link"); return -EACCES; } @@ -993,7 +993,7 @@ static int may_linkat(struct path *link) if (safe_hardlink_source(inode) || inode_owner_or_capable(inode)) return 0; - audit_log_link_denied("linkat"); + audit_log_path_denied(AUDIT_ANOM_LINK, "linkat"); return -EPERM; } @@ -1031,6 +1031,10 @@ static int may_create_in_sticky(struct dentry * const dir, (dir->d_inode->i_mode & 0020 && ((sysctl_protected_fifos >= 2 && S_ISFIFO(inode->i_mode)) || (sysctl_protected_regular >= 2 && S_ISREG(inode->i_mode))))) { + const char *operation = S_ISFIFO(inode->i_mode) ? + "sticky_create_fifo" : + "sticky_create_regular"; + audit_log_path_denied(AUDIT_ANOM_CREAT, operation); return -EACCES; } return 0; diff --git a/include/linux/audit.h b/include/linux/audit.h index aee3dc9eb378..f9ceae57ca8d 100644 --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -156,7 +156,8 @@ extern void audit_log_d_path(struct audit_buffer *ab, const struct path *path); extern void audit_log_key(struct audit_buffer *ab, char *key); -extern void audit_log_link_denied(const char *operation); +extern void audit_log_path_denied(int type, + const char *operation); extern void audit_log_lost(const char *message); extern int audit_log_task_context(struct audit_buffer *ab); @@ -217,7 +218,7 @@ static inline void audit_log_d_path(struct audit_buffer *ab, { } static inline void audit_log_key(struct audit_buffer *ab, char *key) { } -static inline void audit_log_link_denied(const char *string) +static inline void audit_log_path_denied(int type, const char *operation) { } static inline int audit_log_task_context(struct audit_buffer *ab) { diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h index c89c6495983d..3ad935527177 100644 --- a/include/uapi/linux/audit.h +++ b/include/uapi/linux/audit.h @@ -143,6 +143,7 @@ #define AUDIT_ANOM_PROMISCUOUS 1700 /* Device changed promiscuous mode */ #define AUDIT_ANOM_ABEND 1701 /* Process ended abnormally */ #define AUDIT_ANOM_LINK 1702 /* Suspicious use of file links */ +#define AUDIT_ANOM_CREAT 1703 /* Suspicious file creation */ #define AUDIT_INTEGRITY_DATA 1800 /* Data integrity verification */ #define AUDIT_INTEGRITY_METADATA 1801 /* Metadata integrity verification */ #define AUDIT_INTEGRITY_STATUS 1802 /* Integrity enable status */ diff --git a/kernel/audit.c b/kernel/audit.c index da8dc0db5bd3..d75485aa25ff 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -2155,18 +2155,19 @@ void audit_log_task_info(struct audit_buffer *ab) EXPORT_SYMBOL(audit_log_task_info); /** - * audit_log_link_denied - report a link restriction denial - * @operation: specific link operation + * audit_log_path_denied - report a path restriction denial + * @type: audit message type (AUDIT_ANOM_LINK, AUDIT_ANOM_CREAT, etc) + * @operation: specific operation name */ -void audit_log_link_denied(const char *operation) +void audit_log_path_denied(int type, const char *operation) { struct audit_buffer *ab; if (!audit_enabled || audit_dummy_context()) return; - /* Generate AUDIT_ANOM_LINK with subject, operation, outcome. */ - ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_ANOM_LINK); + /* Generate log with subject, operation, outcome. */ + ab = audit_log_start(audit_context(), GFP_KERNEL, type); if (!ab) return; audit_log_format(ab, "op=%s", operation); -- 2.17.1 -- Kees Cook

5 years, 2 months

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[PATCH v2] audit: Report suspicious O_CREAT usage

by Kees Cook

This renames the very specific audit_log_link_denied() to audit_log_path_denied() and adds the AUDIT_* type as an argument. This allows for the creation of the new AUDIT_ANOM_CREAT that can be used to report the fifo/regular file creation restrictions that were introduced in commit 30aba6656f61 ("namei: allow restricted O_CREAT of FIFOs and regular files"). Additionally further clarifies the existing "operations" strings. Signed-off-by: Kees Cook <keescook(a)chromium.org> --- v2: - fix build failure typo in CONFIG_AUDIT=n case - improve operations naming (paul) --- fs/namei.c | 8 ++++++-- include/linux/audit.h | 5 +++-- include/uapi/linux/audit.h | 1 + kernel/audit.c | 11 ++++++----- 4 files changed, 16 insertions(+), 9 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 671c3c1a3425..2d5d245ae723 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -925,7 +925,7 @@ static inline int may_follow_link(struct nameidata *nd) return -ECHILD; audit_inode(nd->name, nd->stack[0].link.dentry, 0); - audit_log_link_denied("follow_link"); + audit_log_path_denied(AUDIT_ANOM_LINK, "sticky_follow_link"); return -EACCES; } @@ -993,7 +993,7 @@ static int may_linkat(struct path *link) if (safe_hardlink_source(inode) || inode_owner_or_capable(inode)) return 0; - audit_log_link_denied("linkat"); + audit_log_path_denied(AUDIT_ANOM_LINK, "unowned_linkat"); return -EPERM; } @@ -1031,6 +1031,10 @@ static int may_create_in_sticky(struct dentry * const dir, (dir->d_inode->i_mode & 0020 && ((sysctl_protected_fifos >= 2 && S_ISFIFO(inode->i_mode)) || (sysctl_protected_regular >= 2 && S_ISREG(inode->i_mode))))) { + const char *operation = S_ISFIFO(inode->i_mode) ? + "sticky_create_fifo" : + "sticky_create_regular"; + audit_log_path_denied(AUDIT_ANOM_CREAT, operation); return -EACCES; } return 0; diff --git a/include/linux/audit.h b/include/linux/audit.h index aee3dc9eb378..f9ceae57ca8d 100644 --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -156,7 +156,8 @@ extern void audit_log_d_path(struct audit_buffer *ab, const struct path *path); extern void audit_log_key(struct audit_buffer *ab, char *key); -extern void audit_log_link_denied(const char *operation); +extern void audit_log_path_denied(int type, + const char *operation); extern void audit_log_lost(const char *message); extern int audit_log_task_context(struct audit_buffer *ab); @@ -217,7 +218,7 @@ static inline void audit_log_d_path(struct audit_buffer *ab, { } static inline void audit_log_key(struct audit_buffer *ab, char *key) { } -static inline void audit_log_link_denied(const char *string) +static inline void audit_log_path_denied(int type, const char *operation) { } static inline int audit_log_task_context(struct audit_buffer *ab) { diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h index c89c6495983d..3ad935527177 100644 --- a/include/uapi/linux/audit.h +++ b/include/uapi/linux/audit.h @@ -143,6 +143,7 @@ #define AUDIT_ANOM_PROMISCUOUS 1700 /* Device changed promiscuous mode */ #define AUDIT_ANOM_ABEND 1701 /* Process ended abnormally */ #define AUDIT_ANOM_LINK 1702 /* Suspicious use of file links */ +#define AUDIT_ANOM_CREAT 1703 /* Suspicious file creation */ #define AUDIT_INTEGRITY_DATA 1800 /* Data integrity verification */ #define AUDIT_INTEGRITY_METADATA 1801 /* Metadata integrity verification */ #define AUDIT_INTEGRITY_STATUS 1802 /* Integrity enable status */ diff --git a/kernel/audit.c b/kernel/audit.c index da8dc0db5bd3..d75485aa25ff 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -2155,18 +2155,19 @@ void audit_log_task_info(struct audit_buffer *ab) EXPORT_SYMBOL(audit_log_task_info); /** - * audit_log_link_denied - report a link restriction denial - * @operation: specific link operation + * audit_log_path_denied - report a path restriction denial + * @type: audit message type (AUDIT_ANOM_LINK, AUDIT_ANOM_CREAT, etc) + * @operation: specific operation name */ -void audit_log_link_denied(const char *operation) +void audit_log_path_denied(int type, const char *operation) { struct audit_buffer *ab; if (!audit_enabled || audit_dummy_context()) return; - /* Generate AUDIT_ANOM_LINK with subject, operation, outcome. */ - ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_ANOM_LINK); + /* Generate log with subject, operation, outcome. */ + ab = audit_log_start(audit_context(), GFP_KERNEL, type); if (!ab) return; audit_log_format(ab, "op=%s", operation); -- 2.17.1 -- Kees Cook

5 years, 2 months

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[PATCH] audit: Report suspicious O_CREAT usage

by Kees Cook

This renames the very specific audit_log_link_denied() to audit_log_path_denied() and adds the AUDIT_* type as an argument. This allows for the creation of the new AUDIT_ANOM_CREAT that can be used to report the fifo/regular file creation restrictions that were introduced in commit 30aba6656f61 ("namei: allow restricted O_CREAT of FIFOs and regular files"). Without this change, discovering that the restriction is enabled can be very challenging: https://lore.kernel.org/lkml/CA+jJMxvkqjXHy3DnV5MVhFTL2RUhg0WQ-XVFW3ngDQO... Reported-by: Jérémie Galarneau <jeremie.galarneau(a)efficios.com> Signed-off-by: Kees Cook <keescook(a)chromium.org> --- This is not a complete fix because reporting was broken in commit 15564ff0a16e ("audit: make ANOM_LINK obey audit_enabled and audit_dummy_context") which specifically goes against the intention of these records: they should _always_ be reported. If auditing isn't enabled, they should be ratelimited. Instead of using audit, should this just go back to using pr_ratelimited()? --- fs/namei.c | 7 +++++-- include/linux/audit.h | 5 +++-- include/uapi/linux/audit.h | 1 + kernel/audit.c | 11 ++++++----- 4 files changed, 15 insertions(+), 9 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 671c3c1a3425..0e60f81e1d5a 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -925,7 +925,7 @@ static inline int may_follow_link(struct nameidata *nd) return -ECHILD; audit_inode(nd->name, nd->stack[0].link.dentry, 0); - audit_log_link_denied("follow_link"); + audit_log_path_denied(AUDIT_ANOM_LINK, "follow_link"); return -EACCES; } @@ -993,7 +993,7 @@ static int may_linkat(struct path *link) if (safe_hardlink_source(inode) || inode_owner_or_capable(inode)) return 0; - audit_log_link_denied("linkat"); + audit_log_path_denied(AUDIT_ANOM_LINK, "linkat"); return -EPERM; } @@ -1031,6 +1031,9 @@ static int may_create_in_sticky(struct dentry * const dir, (dir->d_inode->i_mode & 0020 && ((sysctl_protected_fifos >= 2 && S_ISFIFO(inode->i_mode)) || (sysctl_protected_regular >= 2 && S_ISREG(inode->i_mode))))) { + audit_log_path_denied(AUDIT_ANOM_CREAT, + S_ISFIFO(inode->i_mode) ? "fifo" + : "regular"); return -EACCES; } return 0; diff --git a/include/linux/audit.h b/include/linux/audit.h index aee3dc9eb378..b3715e2ee1c5 100644 --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -156,7 +156,8 @@ extern void audit_log_d_path(struct audit_buffer *ab, const struct path *path); extern void audit_log_key(struct audit_buffer *ab, char *key); -extern void audit_log_link_denied(const char *operation); +extern void audit_log_path_denied(int type, + const char *operation); extern void audit_log_lost(const char *message); extern int audit_log_task_context(struct audit_buffer *ab); @@ -217,7 +218,7 @@ static inline void audit_log_d_path(struct audit_buffer *ab, { } static inline void audit_log_key(struct audit_buffer *ab, char *key) { } -static inline void audit_log_link_denied(const char *string) +static inline void audit_log_path_denied(int type, const char *string); { } static inline int audit_log_task_context(struct audit_buffer *ab) { diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h index c89c6495983d..3ad935527177 100644 --- a/include/uapi/linux/audit.h +++ b/include/uapi/linux/audit.h @@ -143,6 +143,7 @@ #define AUDIT_ANOM_PROMISCUOUS 1700 /* Device changed promiscuous mode */ #define AUDIT_ANOM_ABEND 1701 /* Process ended abnormally */ #define AUDIT_ANOM_LINK 1702 /* Suspicious use of file links */ +#define AUDIT_ANOM_CREAT 1703 /* Suspicious file creation */ #define AUDIT_INTEGRITY_DATA 1800 /* Data integrity verification */ #define AUDIT_INTEGRITY_METADATA 1801 /* Metadata integrity verification */ #define AUDIT_INTEGRITY_STATUS 1802 /* Integrity enable status */ diff --git a/kernel/audit.c b/kernel/audit.c index da8dc0db5bd3..ed7402ac81b6 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -2155,18 +2155,19 @@ void audit_log_task_info(struct audit_buffer *ab) EXPORT_SYMBOL(audit_log_task_info); /** - * audit_log_link_denied - report a link restriction denial - * @operation: specific link operation + * audit_log_path_denied - report a path restriction denial + * @type: audit message type (AUDIT_ANOM_LINK, AUDIT_ANOM_CREAT, etc) + * @operation: specific operation name */ -void audit_log_link_denied(const char *operation) +void audit_log_path_denied(int type, const char *operation) { struct audit_buffer *ab; if (!audit_enabled || audit_dummy_context()) return; - /* Generate AUDIT_ANOM_LINK with subject, operation, outcome. */ - ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_ANOM_LINK); + /* Generate log with subject, operation, outcome. */ + ab = audit_log_start(audit_context(), GFP_KERNEL, type); if (!ab) return; audit_log_format(ab, "op=%s", operation); -- 2.17.1 -- Kees Cook

5 years, 2 months

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[PATCH] audit_set_pid: add wmode to man page

by Nick Black

audit_set_pid: add wmode to man page The audit_set_pid man page is missing the third parameter. I've added it, and briefly extended the usage. Signed-off-by: Nick Black <nickblack(a)linux.com> --- docs/audit_set_pid.3 | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/docs/audit_set_pid.3 b/docs/audit_set_pid.3 index d2b33db..87c41fb 100644 --- a/docs/audit_set_pid.3 +++ b/docs/audit_set_pid.3 @@ -5,11 +5,11 @@ audit_set_pid \- Set audit daemon process ID .B #include <libaudit.h> .sp -int audit_set_pid (int fd, int pid); +int audit_set_pid (int fd, int pid, rep_wait_t wmode); .SH "DESCRIPTION" -audit_set_pid tells the kernel what the pid is of the audit daemon. When the pid is set to 0, the kernel will log all events to syslog. Otherwise it will try to send events to the netlink connection that has the same pid given by this function. If for some reason the process goes away, the kernel will automatically set the value to 0 itself. Usually this function is called by the audit daemon and not an external program. +audit_set_pid tells the kernel what the pid is of the audit daemon. When the pid is set to 0, the kernel will log all events to syslog. Otherwise it will try to send events to the netlink connection that has the same pid given by this function. If for some reason the process goes away, the kernel will automatically set the value to 0 itself. Usually this function is called by the audit daemon and not an external program. If wmode is WAIT_YES, the function will wait for an ACK from the kernel. .SH "RETURN VALUE" -- 2.23.0 -- nick black -=- https://www.nick-black.com to make an apple pie from scratch, you need first invent a universe.

5 years, 2 months

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Linux-audit October 2019