diff mbox series

[v1,net,08/15] tcp: Fix data-races around sysctl_tcp_migrate_req.

Message ID 20220715171755.38497-9-kuniyu@amazon.com (mailing list archive)
State Accepted
Commit 4177f545895b1da08447a80692f30617154efa6e
Delegated to: Netdev Maintainers
Headers show
Series sysctl: Fix data-races around ipv4_net_table (Round 3). | 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 3 blamed authors not CCed: daniel@iogearbox.net kafai@fb.com benh@amazon.com; 3 maintainers not CCed: daniel@iogearbox.net kafai@fb.com benh@amazon.com
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, 16 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 15, 2022, 5:17 p.m. UTC 
While reading sysctl_tcp_migrate_req, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its readers.

Fixes: f9ac779f881c ("net: Introduce net.ipv4.tcp_migrate_req.")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
---
 net/core/sock_reuseport.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/net/core/sock_reuseport.c b/net/core/sock_reuseport.c
index 3f00a28fe762..5daa1fa54249 100644
--- a/net/core/sock_reuseport.c
+++ b/net/core/sock_reuseport.c
@@ -387,7 +387,7 @@  void reuseport_stop_listen_sock(struct sock *sk)
 		prog = rcu_dereference_protected(reuse->prog,
 						 lockdep_is_held(&reuseport_lock));
 
-		if (sock_net(sk)->ipv4.sysctl_tcp_migrate_req ||
+		if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_migrate_req) ||
 		    (prog && prog->expected_attach_type == BPF_SK_REUSEPORT_SELECT_OR_MIGRATE)) {
 			/* Migration capable, move sk from the listening section
 			 * to the closed section.
@@ -545,7 +545,7 @@  struct sock *reuseport_migrate_sock(struct sock *sk,
 	hash = migrating_sk->sk_hash;
 	prog = rcu_dereference(reuse->prog);
 	if (!prog || prog->expected_attach_type != BPF_SK_REUSEPORT_SELECT_OR_MIGRATE) {
-		if (sock_net(sk)->ipv4.sysctl_tcp_migrate_req)
+		if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_migrate_req))
 			goto select_by_hash;
 		goto failure;
 	}