linux/net/tls
Jann Horn 53f2cb491b tls: fix NULL deref on tls_sw_splice_eof() with empty record
syzkaller discovered that if tls_sw_splice_eof() is executed as part of
sendfile() when the plaintext/ciphertext sk_msg are empty, the send path
gets confused because the empty ciphertext buffer does not have enough
space for the encryption overhead. This causes tls_push_record() to go on
the `split = true` path (which is only supposed to be used when interacting
with an attached BPF program), and then get further confused and hit the
tls_merge_open_record() path, which then assumes that there must be at
least one populated buffer element, leading to a NULL deref.

It is possible to have empty plaintext/ciphertext buffers if we previously
bailed from tls_sw_sendmsg_locked() via the tls_trim_both_msgs() path.
tls_sw_push_pending_record() already handles this case correctly; let's do
the same check in tls_sw_splice_eof().

Fixes: df720d288d ("tls/sw: Use splice_eof() to flush")
Cc: stable@vger.kernel.org
Reported-by: syzbot+40d43509a099ea756317@syzkaller.appspotmail.com
Signed-off-by: Jann Horn <jannh@google.com>
Link: https://lore.kernel.org/r/20231122214447.675768-1-jannh@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-11-23 08:51:45 -08:00
..
Kconfig net/tls: Select SOCK_RX_QUEUE_MAPPING from TLS_DEVICE 2021-02-11 19:08:06 -08:00
Makefile tls: rx: async: hold onto the input skb 2022-07-18 11:24:11 +01:00
tls_device_fallback.c tls: rename MAX_IV_SIZE to TLS_MAX_IV_SIZE 2023-10-13 11:26:09 +01:00
tls_device.c tls: don't reset prot->aad_size and prot->tail_size for TLS_HW 2023-10-23 10:15:09 -07:00
tls_main.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2023-10-19 13:29:01 -07:00
tls_proc.c tls: rx: add counter for NoPad violations 2022-07-11 19:48:33 -07:00
tls_strp.c net/tls: Use tcp_read_sock() instead of ops->read_sock() 2023-07-27 19:49:35 -07:00
tls_sw.c tls: fix NULL deref on tls_sw_splice_eof() with empty record 2023-11-23 08:51:45 -08:00
tls_toe.c tls: create an internal header 2022-07-08 18:38:45 -07:00
tls.h tls: don't reset prot->aad_size and prot->tail_size for TLS_HW 2023-10-23 10:15:09 -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