diff options
| author | John Stultz <john.stultz@linaro.org> | 2012-09-17 22:32:08 -0400 |
|---|---|---|
| committer | Willy Tarreau <w@1wt.eu> | 2012-10-07 23:37:09 +0200 |
| commit | 436b6be6cb5bbffb227b5a414e7a1c03fe941b43 (patch) | |
| tree | f24e5c680b7ab6b291c1512241d0291375459826 /kernel | |
| parent | dfc4098e83abd567a4f4f17c2d20869cadcf9509 (diff) | |
time: Improve sanity checking of timekeeping inputs
This is a -stable backport of 4e8b14526ca7fb046a81c94002c1c43b6fdf0e9b
Unexpected behavior could occur if the time is set to a value large
enough to overflow a 64bit ktime_t (which is something larger then the
year 2262).
Also unexpected behavior could occur if large negative offsets are
injected via adjtimex.
So this patch improves the sanity check timekeeping inputs by
improving the timespec_valid() check, and then makes better use of
timespec_valid() to make sure we don't set the time to an invalid
negative value or one that overflows ktime_t.
Note: This does not protect from setting the time close to overflowing
ktime_t and then letting natural accumulation cause the overflow.
Reported-by: CAI Qian <caiqian@redhat.com>
Reported-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Zhouping Liu <zliu@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1344454580-17031-1-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linux Kernel <linux-kernel@vger.kernel.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/time/timekeeping.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 3f7e53fc240f..85d51c4707e7 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -354,7 +354,7 @@ int do_settimeofday(struct timespec *tv) struct timespec ts_delta; unsigned long flags; - if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC) + if (!timespec_valid(tv)) return -EINVAL; write_seqlock_irqsave(&xtime_lock, flags); @@ -570,7 +570,20 @@ void __init timekeeping_init(void) struct timespec now, boot; read_persistent_clock(&now); + if (!timespec_valid(&now)) { + printk("WARNING: Persistent clock returned invalid value!\n" + " Check your CMOS/BIOS settings.\n"); + now.tv_sec = 0; + now.tv_nsec = 0; + } + read_boot_clock(&boot); + if (!timespec_valid(&boot)) { + printk("WARNING: Boot clock returned invalid value!\n" + " Check your CMOS/BIOS settings.\n"); + boot.tv_sec = 0; + boot.tv_nsec = 0; + } write_seqlock_irqsave(&xtime_lock, flags); |