linux/net/tls
Jakub Kicinski 91359966e2 net: tls: prevent chain-after-chain in plain text SG
[ Upstream commit ff26a0e837 ]

Sashiko points out that if end = 0 (start != 0) the current
code will create a chain link to content type right after
the wrap link:

  This would create a chain where the wrap link points directly
  to another chain link. The scatterlist API sg_next iterator
  does not recursively resolve consecutive chain links.

meaning this is illegal input to crypto.

The wrapping link is unnecessary if end = 0. end is the entry after
the last one used so end = 0 means there's nothing pushed after
the wrap:

   end         start            i
    v            v              v
  [   ]...[   ][ d ][ d ][ d ][ d ][rsv for wrap]

Skip the wrapping in this case.

TLS 1.3 can use the "wrapping slot" for it's chaining if end = 0.
This avoids the chain-after-chain.

Move the wrap chaining before marking END and chaining off content
type, that feels like more logical ordering to me, but should not
matter from functional perspective.

Reported-by: Sashiko <sashiko-bot@kernel.org>
Fixes: 9aaaa56845 ("bpf: Sockmap/tls, skmsg can have wrapped skmsg that needs extra chaining")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Link: https://patch.msgid.link/20260511174920.433155-3-kuba@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
History 2026-06-01 17:35:50 +02:00
..
Kconfig net/tls: Select SOCK_RX_QUEUE_MAPPING from TLS_DEVICE 2021-02-11 19:08:06 -08:00
Makefile net/tls: add skeleton of MIB statistics 2019-10-05 16:29:00 -07:00
tls_device.c tls: Use __sk_dst_get() and dst_dev_rcu() in get_netdev_for_sock(). 2026-02-06 16:42:01 +01:00
tls_device_fallback.c net/tls: Fix use-after-free after the TLS device goes down and up 2021-06-01 15:58:05 -07:00
tls_main.c tls: always set record_type in tls_process_cmsg 2025-10-29 14:03:08 +01:00
tls_proc.c net: fix proc_fs init handling in af_packet and tls 2020-12-14 19:39:30 -08:00
tls_sw.c net: tls: prevent chain-after-chain in plain text SG 2026-06-01 17:35:50 +02:00
tls_toe.c net/tls: rename tls_hw_* functions tls_toe_* 2019-10-04 14:07:07 -07:00
trace.c net/tls: add tracing for device/offload events 2019-10-05 16:29:00 -07:00
trace.h net/tls: add device decrypted trace point 2019-10-05 16:29:00 -07:00