From 2d87a0674bd60d855e4008e2d84f5b23d7cb9b7d Mon Sep 17 00:00:00 2001 From: Ondrej Mosnacek Date: Wed, 10 Apr 2019 11:14:19 +0200 Subject: timekeeping: Audit clock adjustments Emit an audit record whenever the system clock is changed (i.e. shifted by a non-zero offset) by a syscall from userspace. The syscalls than can (at the time of writing) trigger such record are: - settimeofday(2), stime(2), clock_settime(2) -- via do_settimeofday64() - adjtimex(2), clock_adjtime(2) -- via do_adjtimex() The new records have type AUDIT_TIME_INJOFFSET and contain the following fields: - sec -- the 'seconds' part of the offset - nsec -- the 'nanoseconds' part of the offset Example record (time was shifted backwards by ~15.875 seconds): type=TIME_INJOFFSET msg=audit(1530616049.652:13): sec=-16 nsec=124887145 The records of this type will be associated with the corresponding syscall records. Signed-off-by: Ondrej Mosnacek Reviewed-by: Richard Guy Briggs Reviewed-by: Thomas Gleixner [PM: fixed a line width problem in __audit_tk_injoffset()] Signed-off-by: Paul Moore --- include/linux/audit.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'include/linux/audit.h') diff --git a/include/linux/audit.h b/include/linux/audit.h index 1e69d9fe16da..2c62c0468888 100644 --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -365,6 +365,7 @@ extern void __audit_log_capset(const struct cred *new, const struct cred *old); extern void __audit_mmap_fd(int fd, int flags); extern void __audit_log_kern_module(char *name); extern void __audit_fanotify(unsigned int response); +extern void __audit_tk_injoffset(struct timespec64 offset); static inline void audit_ipc_obj(struct kern_ipc_perm *ipcp) { @@ -467,6 +468,16 @@ static inline void audit_fanotify(unsigned int response) __audit_fanotify(response); } +static inline void audit_tk_injoffset(struct timespec64 offset) +{ + /* ignore no-op events */ + if (offset.tv_sec == 0 && offset.tv_nsec == 0) + return; + + if (!audit_dummy_context()) + __audit_tk_injoffset(offset); +} + extern int audit_n_rules; extern int audit_signals; #else /* CONFIG_AUDITSYSCALL */ @@ -580,6 +591,9 @@ static inline void audit_log_kern_module(char *name) static inline void audit_fanotify(unsigned int response) { } +static inline void audit_tk_injoffset(struct timespec64 offset) +{ } + static inline void audit_ptrace(struct task_struct *t) { } #define audit_n_rules 0 -- cgit