diff mbox series

[v1,net,01/15] ipv4: Fix a data-race around sysctl_fib_multipath_use_neigh.

Message ID 20220718172653.22111-2-kuniyu@amazon.com (mailing list archive)
State Accepted
Commit 87507bcb4f5de16bb419e9509d874f4db6c0ad0f
Delegated to: Netdev Maintainers
Headers show
Series sysctl: Fix data-races around ipv4_net_table (Round 4). | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net, async
netdev/fixes_present success Fixes tag present in non-next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 2 this patch: 2
netdev/cc_maintainers fail 1 blamed authors not CCed: ja@ssi.bg; 2 maintainers not CCed: yoshfuji@linux-ipv6.org ja@ssi.bg
netdev/build_clang success Errors and warnings before: 6 this patch: 6
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 2 this patch: 2
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 8 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Kuniyuki Iwashima July 18, 2022, 5:26 p.m. UTC
While reading sysctl_fib_multipath_use_neigh, it can be changed
concurrently.  Thus, we need to add READ_ONCE() to its reader.

Fixes: a6db4494d218 ("net: ipv4: Consider failed nexthops in multipath routes")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
---
 net/ipv4/fib_semantics.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index d9fdcbae16ee..db7b2503f068 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -2216,7 +2216,7 @@  void fib_select_multipath(struct fib_result *res, int hash)
 	}
 
 	change_nexthops(fi) {
-		if (net->ipv4.sysctl_fib_multipath_use_neigh) {
+		if (READ_ONCE(net->ipv4.sysctl_fib_multipath_use_neigh)) {
 			if (!fib_good_nh(nexthop_nh))
 				continue;
 			if (!first) {