From: Xin Long <lucien.xin@gmail.com> stable inclusion from stable-v6.18.40 commit a8323fb2ab6cd6978f359daeed6688e0cadf32ba category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/17334 CVE: CVE-2026-72383 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit 976c19de0f22a857ba0112f39635f8fd7a257568 ] sctp_free_addr_wq() previously removed addr_wq_timer using timer_delete() while holding addr_wq_lock. However, timer_delete() does not guarantee that a currently running timer handler has completed. This allows a race with sctp_addr_wq_timeout_handler(), where the handler may still run after addr_waitq has been freed, acquire addr_wq_lock, and access freed memory, leading to a use-after-free. Fix this by calling timer_shutdown_sync() before taking addr_wq_lock. This guarantees that any in-flight timer handler has finished and prevents the timer from being re-armed during teardown, making subsequent cleanup safe. Fixes: 4db67e808640 ("sctp: Make the address lists per network namespace") Reported-by: Sashiko <sashiko-bot@kernel.org> Signed-off-by: Xin Long <lucien.xin@gmail.com> Link: https://patch.msgid.link/5dc95f295bdb5c3f60e880dd9aa5112dc5c071cc.1782757874... Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Conflicts: net/sctp/protocol.c [Just context conflicts] Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com> --- net/sctp/protocol.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c index 0beb9a82c2a3..a862644a6caa 100644 --- a/net/sctp/protocol.c +++ b/net/sctp/protocol.c @@ -690,12 +690,13 @@ static void sctp_addr_wq_timeout_handler(struct timer_list *t) static void sctp_free_addr_wq(struct net *net) { struct sctp_sockaddr_entry *addrw; struct sctp_sockaddr_entry *temp; + timer_shutdown_sync(&net->sctp.addr_wq_timer); + spin_lock_bh(&net->sctp.addr_wq_lock); - del_timer(&net->sctp.addr_wq_timer); list_for_each_entry_safe(addrw, temp, &net->sctp.addr_waitq, list) { list_del(&addrw->list); kfree(addrw); } spin_unlock_bh(&net->sctp.addr_wq_lock); -- 2.43.0