From 4ab26bce3969f8fd925fe6f6f551e4d1a508c68b Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Wed, 16 Jul 2025 07:38:50 -0700 Subject: [PATCH] tls: always refresh the queue when reading sock After recent changes in net-next TCP compacts skbs much more aggressively. This unearthed a bug in TLS where we may try to operate on an old skb when checking if all skbs in the queue have matching decrypt state and geometry. BUG: KASAN: slab-use-after-free in tls_strp_check_rcv+0x898/0x9a0 [tls] (net/tls/tls_strp.c:436 net/tls/tls_strp.c:530 net/tls/tls_strp.c:544) Read of size 4 at addr ffff888013085750 by task tls/13529 CPU: 2 UID: 0 PID: 13529 Comm: tls Not tainted 6.16.0-rc5-virtme Call Trace: kasan_report+0xca/0x100 tls_strp_check_rcv+0x898/0x9a0 [tls] tls_rx_rec_wait+0x2c9/0x8d0 [tls] tls_sw_recvmsg+0x40f/0x1aa0 [tls] inet_recvmsg+0x1c3/0x1f0 Always reload the queue, fast path is to have the record in the queue when we wake, anyway (IOW the path going down "if !strp->stm.full_len"). Fixes: 0d87bbd39d7f ("tls: strp: make sure the TCP skbs do not have overlapping data") Link: https://patch.msgid.link/20250716143850.1520292-1-kuba@kernel.org Signed-off-by: Jakub Kicinski --- net/tls/tls_strp.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/net/tls/tls_strp.c b/net/tls/tls_strp.c index 65b0da6fdf6a..095cf31bae0b 100644 --- a/net/tls/tls_strp.c +++ b/net/tls/tls_strp.c @@ -512,9 +512,8 @@ static int tls_strp_read_sock(struct tls_strparser *strp) if (inq < strp->stm.full_len) return tls_strp_read_copy(strp, true); + tls_strp_load_anchor_with_queue(strp, inq); if (!strp->stm.full_len) { - tls_strp_load_anchor_with_queue(strp, inq); - sz = tls_rx_msg_size(strp, strp->anchor); if (sz < 0) { tls_strp_abort_strp(strp, sz); -- 2.25.1