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| author | Zeng Tao <prime.zeng@hisilicon.com> | 2020-09-01 17:30:13 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-11-18 18:27:52 +0100 |
| commit | 1b0c077318aa0ba8b0341d6de4f3da58dd0e56f4 (patch) | |
| tree | 3ea4c29fec66105440cf10cf771e6c9dc0a4cf31 /kernel | |
| parent | b3a189022360968e2f62a5ac11f92f9ece59299d (diff) | |
| download | linux-rt-1b0c077318aa0ba8b0341d6de4f3da58dd0e56f4.tar.gz | |
time: Prevent undefined behaviour in timespec64_to_ns()
[ Upstream commit cb47755725da7b90fecbb2aa82ac3b24a7adb89b ]
UBSAN reports:
Undefined behaviour in ./include/linux/time64.h:127:27
signed integer overflow:
17179869187 * 1000000000 cannot be represented in type 'long long int'
Call Trace:
timespec64_to_ns include/linux/time64.h:127 [inline]
set_cpu_itimer+0x65c/0x880 kernel/time/itimer.c:180
do_setitimer+0x8e/0x740 kernel/time/itimer.c:245
__x64_sys_setitimer+0x14c/0x2c0 kernel/time/itimer.c:336
do_syscall_64+0xa1/0x540 arch/x86/entry/common.c:295
Commit bd40a175769d ("y2038: itimer: change implementation to timespec64")
replaced the original conversion which handled time clamping correctly with
timespec64_to_ns() which has no overflow protection.
Fix it in timespec64_to_ns() as this is not necessarily limited to the
usage in itimers.
[ tglx: Added comment and adjusted the fixes tag ]
Fixes: 361a3bf00582 ("time64: Add time64.h header and define struct timespec64")
Signed-off-by: Zeng Tao <prime.zeng@hisilicon.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/1598952616-6416-1-git-send-email-prime.zeng@hisilicon.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/time/itimer.c | 4 |
1 files changed, 0 insertions, 4 deletions
diff --git a/kernel/time/itimer.c b/kernel/time/itimer.c index f26acef5d7b4..7f718565507b 100644 --- a/kernel/time/itimer.c +++ b/kernel/time/itimer.c @@ -153,10 +153,6 @@ static void set_cpu_itimer(struct task_struct *tsk, unsigned int clock_id, u64 oval, nval, ointerval, ninterval; struct cpu_itimer *it = &tsk->signal->it[clock_id]; - /* - * Use the to_ktime conversion because that clamps the maximum - * value to KTIME_MAX and avoid multiplication overflows. - */ nval = ktime_to_ns(timeval_to_ktime(value->it_value)); ninterval = ktime_to_ns(timeval_to_ktime(value->it_interval)); |