Files
linux/include/net
Kyle Zeng 1ee90b77b7 net: guard timestamp cmsgs to real error queue skbs
skb_is_err_queue() treats PACKET_OUTGOING as the sole marker for an skb
from sk_error_queue. That assumption is not true for AF_PACKET sockets:
outgoing packet taps are also delivered to packet sockets with
skb->pkt_type == PACKET_OUTGOING, but their skb->cb is owned by AF_PACKET
instead of struct sock_exterr_skb.

If such an skb is received with timestamping enabled, the generic
timestamp cmsg path can read AF_PACKET control-buffer state as
sock_exterr_skb::opt_stats. With SO_RXQ_OVFL enabled, the packet drop
counter overlaps opt_stats. An odd drop count makes the path emit
SCM_TIMESTAMPING_OPT_STATS with skb->len and skb->data. For non-linear
skbs this copies past the linear head and can trigger hardened usercopy or
disclose adjacent heap contents.

Keep skb_is_err_queue() local to net/socket.c, but make it verify that
the PACKET_OUTGOING marker is paired with the sock_rmem_free destructor
installed by sock_queue_err_skb(). AF_PACKET receive skbs use normal
receive ownership and no longer pass as error-queue skbs, while legitimate
sk_error_queue entries keep the PACKET_OUTGOING marker and sock_rmem_free
ownership.

Fixes: 8605330aac ("tcp: fix SCM_TIMESTAMPING_OPT_STATS for normal skbs")
Signed-off-by: Kyle Zeng <kylebot@openai.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20260607021819.49698-1-kylebot@openai.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-09 18:32:08 -07:00
..
2025-04-24 17:03:45 -07:00
2025-07-08 18:05:25 -07:00
2022-08-09 22:14:02 -07:00
2024-05-08 10:35:09 +01:00
2024-08-26 09:37:23 -07:00
2024-11-13 18:49:50 -08:00
2024-08-26 09:37:23 -07:00
2025-08-26 17:34:31 -07:00
2026-01-21 19:28:32 -08:00
2024-05-07 01:35:55 +02:00
2024-08-26 09:37:23 -07:00
2024-12-06 17:43:08 -08:00
2024-08-26 09:37:23 -07:00
2025-09-18 12:32:06 +02:00
2024-08-26 09:37:23 -07:00
2024-08-26 09:37:23 -07:00
2025-04-11 18:58:10 -07:00
2025-07-04 09:32:35 +02:00
2024-05-30 18:29:38 -07:00
2025-09-08 18:06:21 -07:00
2025-07-11 11:00:57 -07:00
2023-07-28 14:07:59 -07:00
2026-03-13 18:57:44 -07:00
2026-04-06 18:43:51 -07:00
2026-03-16 19:28:21 -07:00