shinys000114/linux
1
0
Fork 0
mirror of https://github.com/hardkernel/linux.git synced 2026-06-06 10:58:48 +09:00
Code Issues Packages Projects Releases Wiki Activity

sysctl: Fix data-races in proc_dou8vec_minmax().

Browse Source 
commit 7dee5d7747 upstream.

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_dou8vec_minmax() to use READ_ONCE() and
WRITE_ONCE() internally to fix data-races on the sysctl side.  For now,
proc_dou8vec_minmax() itself is tolerant to a data-race, but we still
need to add annotations on the other subsystem's side.

Fixes: cb94441306 ("sysctl: add proc_dou8vec_minmax()")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Kuniyuki Iwashima
2022-07-11 17:15:19 -07:00
committed by Greg Kroah-Hartman
parent 56314b90fd
commit f177b382c3
1 changed files with 2 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
kernel/sysctl.c
View File

@@ -1109,13 +1109,13 @@ int proc_dou8vec_minmax(struct ctl_table *table, int write,
tmp.maxlen = sizeof(val); tmp.maxlen = sizeof(val);
tmp.data = &val; tmp.data = &val;
val = *data; val = READ_ONCE(*data);
res = do_proc_douintvec(&tmp, write, buffer, lenp, ppos, res = do_proc_douintvec(&tmp, write, buffer, lenp, ppos,
do_proc_douintvec_minmax_conv, &param); do_proc_douintvec_minmax_conv, &param);
if (res) if (res)
return res; return res;
if (write) if (write)
*data = val; WRITE_ONCE(*data, val);
return 0; return 0;
} }
EXPORT_SYMBOL_GPL(proc_dou8vec_minmax); EXPORT_SYMBOL_GPL(proc_dou8vec_minmax);