diff mbox series

[net,1/7] mptcp: fix locking in mptcp_nl_cmd_sf_destroy()

Message ID 20220705213217.146898-2-mathew.j.martineau@linux.intel.com (mailing list archive)
State Accepted
Commit 5ccecaec5c1e85cabfda848c6f146da0d8d55bd6
Delegated to: Netdev Maintainers
Headers show
Series mptcp: Path manager fixes for 5.19 | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net
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: kishen.maloor@intel.com; 1 maintainers not CCed: kishen.maloor@intel.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, 51 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Mat Martineau July 5, 2022, 9:32 p.m. UTC 
From: Paolo Abeni <pabeni@redhat.com>

The user-space PM subflow removal path uses a couple of helpers
that must be called under the msk socket lock and the current
code lacks such requirement.

Change the existing lock scope so that the relevant code is under
its protection.

Fixes: 702c2f646d42 ("mptcp: netlink: allow userspace-driven subflow establishment")
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/287
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
---
 net/mptcp/pm_userspace.c | 19 ++++++-------------
 1 file changed, 6 insertions(+), 13 deletions(-)
diff mbox series

Patch

diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
index f56378e4f597..26212bebc5ed 100644
--- a/net/mptcp/pm_userspace.c
+++ b/net/mptcp/pm_userspace.c
@@ -306,15 +306,11 @@  static struct sock *mptcp_nl_find_ssk(struct mptcp_sock *msk,
 				      const struct mptcp_addr_info *local,
 				      const struct mptcp_addr_info *remote)
 {
-	struct sock *sk = &msk->sk.icsk_inet.sk;
 	struct mptcp_subflow_context *subflow;
-	struct sock *found = NULL;
 
 	if (local->family != remote->family)
 		return NULL;
 
-	lock_sock(sk);
-
 	mptcp_for_each_subflow(msk, subflow) {
 		const struct inet_sock *issk;
 		struct sock *ssk;
@@ -347,16 +343,11 @@  static struct sock *mptcp_nl_find_ssk(struct mptcp_sock *msk,
 		}
 
 		if (issk->inet_sport == local->port &&
-		    issk->inet_dport == remote->port) {
-			found = ssk;
-			goto found;
-		}
+		    issk->inet_dport == remote->port)
+			return ssk;
 	}
 
-found:
-	release_sock(sk);
-
-	return found;
+	return NULL;
 }
 
 int mptcp_nl_cmd_sf_destroy(struct sk_buff *skb, struct genl_info *info)
@@ -412,6 +403,7 @@  int mptcp_nl_cmd_sf_destroy(struct sk_buff *skb, struct genl_info *info)
 	}
 
 	sk = &msk->sk.icsk_inet.sk;
+	lock_sock(sk);
 	ssk = mptcp_nl_find_ssk(msk, &addr_l, &addr_r);
 	if (ssk) {
 		struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
@@ -422,8 +414,9 @@  int mptcp_nl_cmd_sf_destroy(struct sk_buff *skb, struct genl_info *info)
 	} else {
 		err = -ESRCH;
 	}
+	release_sock(sk);
 
- destroy_err:
+destroy_err:
 	sock_put((struct sock *)msk);
 	return err;
 }