From 426d22fce0b344184c2b17f6c588b6eeaa419b23 Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Thu, 10 Nov 2022 20:24:43 +0800 Subject: [PATCH] ipv4: Fix a data-race around sysctl_fib_multipath_use_neigh. stable inclusion from stable-v5.10.134 commit e045d672ba06e1d35bacb56374d350de0ac99066 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5ZVR7 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=e045d672ba06e1d35bacb56374d350de0ac99066 -------------------------------- [ Upstream commit 87507bcb4f5de16bb419e9509d874f4db6c0ad0f ] 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 Signed-off-by: David S. Miller Signed-off-by: Sasha Levin Signed-off-by: Zheng Zengkai Reviewed-by: Wei Li --- net/ipv4/fib_semantics.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c index 3e31bed1ab10..f62b1739f63b 100644 --- a/net/ipv4/fib_semantics.c +++ b/net/ipv4/fib_semantics.c @@ -2232,7 +2232,7 @@ 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) { -- GitLab