From: Dmitry Safonov Date: Thu, 21 Nov 2019 00:03:03 +0000 (+0000) Subject: time: Zero the upper 32-bits in __kernel_timespec on 32-bit X-Git-Tag: v5.10.7~3620^2~2 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=7b8474466ed97be458c825f34a85f2c2b84c3f95;p=platform%2Fkernel%2Flinux-rpi.git time: Zero the upper 32-bits in __kernel_timespec on 32-bit On compat interfaces, the high order bits of nanoseconds should be zeroed out. This is because the application code or the libc do not guarantee zeroing of these. If used without zeroing, kernel might be at risk of using timespec values incorrectly. Originally it was handled correctly, but lost during is_compat_syscall() cleanup. Revert the condition back to check CONFIG_64BIT. Fixes: 98f76206b335 ("compat: Cleanup in_compat_syscall() callers") Reported-by: Ben Hutchings Signed-off-by: Dmitry Safonov Signed-off-by: Thomas Gleixner Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20191121000303.126523-1-dima@arista.com --- diff --git a/kernel/time/time.c b/kernel/time/time.c index 5c54ca6..83f403e 100644 --- a/kernel/time/time.c +++ b/kernel/time/time.c @@ -881,7 +881,8 @@ int get_timespec64(struct timespec64 *ts, ts->tv_sec = kts.tv_sec; /* Zero out the padding for 32 bit systems or in compat mode */ - if (IS_ENABLED(CONFIG_64BIT_TIME) && in_compat_syscall()) + if (IS_ENABLED(CONFIG_64BIT_TIME) && (!IS_ENABLED(CONFIG_64BIT) || + in_compat_syscall())) kts.tv_nsec &= 0xFFFFFFFFUL; ts->tv_nsec = kts.tv_nsec;