mirrors/linux
2
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-08-31 08:15:07 -04:00
Code Issues Packages Projects Releases Wiki Activity

timers/itimer: Zero-init old itimerval before copy to userspace

Browse Source 
On native sparc64, struct __kernel_old_timeval contains a four-byte hole
after tv_usec because tv_sec is 64-bit while __kernel_suseconds_t is 32-bit.
put_itimerval() fills only the named fields in a stack-allocated
__kernel_old_itimerval and copies the entire object to userspace, so
getitimer() can expose the two padding holes.

Zero-initialize the aggregate before assigning the fields so implicit
padding is deterministic before it crosses the user/kernel boundary.

Signed-off-by: Jérémy Jean <Jeremy.Jean@oss.cyber.gouv.fr>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Assisted-by: Codex:gpt-5
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260809190428.1523014-1-Jeremy.Jean@oss.cyber.gouv.fr
This commit is contained in:
Jérémy Jean
2026-08-09 19:04:16 +00:00
committed by Thomas Gleixner
parent b17006b452
commit 18c7d85864
1 changed files with 1 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
kernel/time/itimer.c
View File

@@ -100,7 +100,7 @@ static int do_getitimer(int which, struct itimerspec64 *value)
static int put_itimerval(struct __kernel_old_itimerval __user *o,
const struct itimerspec64 *i)
{
struct __kernel_old_itimerval v;
struct __kernel_old_itimerval v = {};
v.it_interval.tv_sec = i->it_interval.tv_sec;
v.it_interval.tv_usec = i->it_interval.tv_nsec / NSEC_PER_USEC;