This is a note to let you know that I've just added the patch titled
inet: fix race in reqsk_queue_unlink()
to the 4.2-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
inet-fix-race-in-reqsk_queue_unlink.patch
and it can be found in the queue-4.2 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From foo@baz Thu Oct 22 17:25:24 PDT 2015
From: Eric Dumazet <[email protected]>
Date: Thu, 1 Oct 2015 05:39:26 -0700
Subject: inet: fix race in reqsk_queue_unlink()
From: Eric Dumazet <[email protected]>
[ Upstream commit 2306c704ce280c97a60d1f45333b822b40281dea ]
reqsk_timer_handler() tests if icsk_accept_queue.listen_opt
is NULL at its beginning.
By the time it calls inet_csk_reqsk_queue_drop() and
reqsk_queue_unlink(), listener might have been closed and
inet_csk_listen_stop() had called reqsk_queue_yank_acceptq()
which sets icsk_accept_queue.listen_opt to NULL
We therefore need to correctly check listen_opt being NULL
after holding syn_wait_lock for proper synchronization.
Fixes: fa76ce7328b2 ("inet: get rid of central tcp/dccp listener timer")
Fixes: b357a364c57c ("inet: fix possible panic in reqsk_queue_unlink()")
Signed-off-by: Eric Dumazet <[email protected]>
Cc: Yuchung Cheng <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
net/ipv4/inet_connection_sock.c | 19 ++++++++++---------
1 file changed, 10 insertions(+), 9 deletions(-)
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -577,21 +577,22 @@ EXPORT_SYMBOL(inet_rtx_syn_ack);
static bool reqsk_queue_unlink(struct request_sock_queue *queue,
struct request_sock *req)
{
- struct listen_sock *lopt = queue->listen_opt;
struct request_sock **prev;
+ struct listen_sock *lopt;
bool found = false;
spin_lock(&queue->syn_wait_lock);
-
- for (prev = &lopt->syn_table[req->rsk_hash]; *prev != NULL;
- prev = &(*prev)->dl_next) {
- if (*prev == req) {
- *prev = req->dl_next;
- found = true;
- break;
+ lopt = queue->listen_opt;
+ if (lopt) {
+ for (prev = &lopt->syn_table[req->rsk_hash]; *prev != NULL;
+ prev = &(*prev)->dl_next) {
+ if (*prev == req) {
+ *prev = req->dl_next;
+ found = true;
+ break;
+ }
}
}
-
spin_unlock(&queue->syn_wait_lock);
if (timer_pending(&req->rsk_timer) && del_timer_sync(&req->rsk_timer))
reqsk_put(req);
Patches currently in stable-queue which might be from [email protected] are
queue-4.2/inet-fix-races-in-reqsk_queue_hash_req.patch
queue-4.2/net-add-pfmemalloc-check-in-sk_add_backlog.patch
queue-4.2/inet-fix-race-in-reqsk_queue_unlink.patch
queue-4.2/net-unix-fix-logic-about-sk_peek_offset.patch
queue-4.2/act_mirred-clear-sender-cpu-before-sending-to-tx.patch
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
