korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-11-15 08:14:15 +08:00
Code Issues Packages Projects Releases Wiki Activity

sysctl: Fix data races in proc_douintvec().

Browse Source 
A sysctl variable is accessed concurrently, and there is always a chance
of data-race.  So, all readers and writers need some basic protection to
avoid load/store-tearing.

This patch changes proc_douintvec() to use READ_ONCE() and WRITE_ONCE()
internally to fix data-races on the sysctl side.  For now, proc_douintvec()
itself is tolerant to a data-race, but we still need to add annotations on
the other subsystem's side.

Fixes: e7d316a02f ("sysctl: handle error writing UINT_MAX to u32 fields")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Kuniyuki Iwashima 2022-07-06 16:39:53 -07:00 committed by David S. Miller
parent 1f1be04b4d
commit 4762b532ec
1 changed files with 2 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
kernel/sysctl.c
View File

@ -472,9 +472,9 @@ static int do_proc_douintvec_conv(unsigned long *lvalp,
if (write) {
if (*lvalp > UINT_MAX)
return -EINVAL;
*valp = *lvalp;
WRITE_ONCE(*valp, *lvalp);
} else {
unsigned int val = *valp;
unsigned int val = READ_ONCE(*valp);
*lvalp = (unsigned long)val;
}
return 0;