diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2018-11-01 13:02:38 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-12-17 21:55:15 +0100 |
| commit | 954648ebf8e27fcbf23b7954b79a22a5cacc83b1 (patch) | |
| tree | 74c06fd42da8eccb84f239df386a88a9cf009d6f /include/linux/posix-timers.h | |
| parent | e47b9b2b005ab8b1b83bc0ac4aa2803cba57182a (diff) | |
posix-timers: Sanitize overrun handling
commit 78c9c4dfbf8c04883941445a195276bb4bb92c76 upstream.
The posix timer overrun handling is broken because the forwarding functions
can return a huge number of overruns which does not fit in an int. As a
consequence timer_getoverrun(2) and siginfo::si_overrun can turn into
random number generators.
The k_clock::timer_forward() callbacks return a 64 bit value now. Make
k_itimer::ti_overrun[_last] 64bit as well, so the kernel internal
accounting is correct. 3Remove the temporary (int) casts.
Add a helper function which clamps the overrun value returned to user space
via timer_getoverrun(2) or siginfo::si_overrun limited to a positive value
between 0 and INT_MAX. INT_MAX is an indicator for user space that the
overrun value has been clamped.
Reported-by: Team OWL337 <icytxw@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <john.stultz@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Link: https://lkml.kernel.org/r/20180626132705.018623573@linutronix.de
[florian: Make patch apply to v4.9.135]
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/linux/posix-timers.h')
| -rw-r--r-- | include/linux/posix-timers.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/include/linux/posix-timers.h b/include/linux/posix-timers.h index 907f3fd191ac..3e28a1a8d823 100644 --- a/include/linux/posix-timers.h +++ b/include/linux/posix-timers.h @@ -65,8 +65,8 @@ struct k_itimer { spinlock_t it_lock; clockid_t it_clock; /* which timer type */ timer_t it_id; /* timer id */ - int it_overrun; /* overrun on pending signal */ - int it_overrun_last; /* overrun on last delivered signal */ + s64 it_overrun; /* overrun on pending signal */ + s64 it_overrun_last; /* overrun on last delivered signal */ int it_requeue_pending; /* waiting to requeue this timer */ #define REQUEUE_PENDING 1 int it_sigev_notify; /* notify word of sigevent struct */ |