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authorMat Martineau <martineau@kernel.org>2025-04-21 19:07:13 +0200
committerJakub Kicinski <kuba@kernel.org>2025-04-23 16:27:58 -0700
commit13b4ece33cf9def67966bb8716783c42cec20617 (patch)
tree4e6418f69658d4f5f5ea44ae775f7450970059c4 /net
parent491ef1117c56476f199b481f8c68820fe4c3a7c2 (diff)
mptcp: pm: Defer freeing of MPTCP userspace path manager entries
When path manager entries are deleted from the local address list, they are first unlinked from the address list using list_del_rcu(). The entries must not be freed until after the RCU grace period, but the existing code immediately frees the entry. Use kfree_rcu_mightsleep() and adjust sk_omem_alloc in open code instead of using the sock_kfree_s() helper. This code path is only called in a netlink handler, so the "might sleep" function is preferable to adding a rarely-used rcu_head member to struct mptcp_pm_addr_entry. Fixes: 88d097316371 ("mptcp: drop free_list for deleting entries") Cc: stable@vger.kernel.org Signed-off-by: Mat Martineau <martineau@kernel.org> Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Link: https://patch.msgid.link/20250421-net-mptcp-pm-defer-freeing-v1-1-e731dc6e86b9@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net')
-rw-r--r--net/mptcp/pm_userspace.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
index 2cb62f026b1f..a715dcbe0146 100644
--- a/net/mptcp/pm_userspace.c
+++ b/net/mptcp/pm_userspace.c
@@ -337,7 +337,11 @@ int mptcp_pm_nl_remove_doit(struct sk_buff *skb, struct genl_info *info)
release_sock(sk);
- sock_kfree_s(sk, match, sizeof(*match));
+ kfree_rcu_mightsleep(match);
+ /* Adjust sk_omem_alloc like sock_kfree_s() does, to match
+ * with allocation of this memory by sock_kmemdup()
+ */
+ atomic_sub(sizeof(*match), &sk->sk_omem_alloc);
err = 0;
out: