kernel/audit.c: avoid negative sleep durations
authorAndrew Morton <akpm@linux-foundation.org>
Fri, 11 Jan 2013 22:32:11 +0000 (14:32 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 11 Jan 2013 22:54:56 +0000 (14:54 -0800)
commit829199197a430dade2519d54f5545c4a094393b8
treeaf50ca9af09b83fd2a5c76cad35bd0603eb33391
parent0644ec0cc8a33fb654e348897ad7684e22a4b5d8
kernel/audit.c: avoid negative sleep durations

audit_log_start() performs the same jiffies comparison in two places.
If sufficient time has elapsed between the two comparisons, the second
one produces a negative sleep duration:

  schedule_timeout: wrong timeout value fffffffffffffff0
  Pid: 6606, comm: trinity-child1 Not tainted 3.8.0-rc1+ #43
  Call Trace:
    schedule_timeout+0x305/0x340
    audit_log_start+0x311/0x470
    audit_log_exit+0x4b/0xfb0
    __audit_syscall_exit+0x25f/0x2c0
    sysret_audit+0x17/0x21

Fix it by performing the comparison a single time.

Reported-by: Dave Jones <davej@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kernel/audit.c