]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commitdiff
net: tls, fix WARNIING in __sk_msg_free
authorJohn Fastabend <john.fastabend@gmail.com>
Sat, 13 Jan 2024 00:32:57 +0000 (16:32 -0800)
committerDavid S. Miller <davem@davemloft.net>
Sun, 14 Jan 2024 12:17:14 +0000 (12:17 +0000)
A splice with MSG_SPLICE_PAGES will cause tls code to use the
tls_sw_sendmsg_splice path in the TLS sendmsg code to move the user
provided pages from the msg into the msg_pl. This will loop over the
msg until msg_pl is full, checked by sk_msg_full(msg_pl). The user
can also set the MORE flag to hint stack to delay sending until receiving
more pages and ideally a full buffer.

If the user adds more pages to the msg than can fit in the msg_pl
scatterlist (MAX_MSG_FRAGS) we should ignore the MORE flag and send
the buffer anyways.

What actually happens though is we abort the msg to msg_pl scatterlist
setup and then because we forget to set 'full record' indicating we
can no longer consume data without a send we fallthrough to the 'continue'
path which will check if msg_data_left(msg) has more bytes to send and
then attempts to fit them in the already full msg_pl. Then next
iteration of sender doing send will encounter a full msg_pl and throw
the warning in the syzbot report.

To fix simply check if we have a full_record in splice code path and
if not send the msg regardless of MORE flag.

Reported-and-tested-by: syzbot+f2977222e0e95cec15c8@syzkaller.appspotmail.com
Reported-by: Edward Adam Davis <eadavis@qq.com>
Fixes: fe1e81d4f73b ("tls/sw: Support MSG_SPLICE_PAGES")
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/tls/tls_sw.c

index e37b4d2e2acde25d6879770629b3996d03860c56..31e8a94dfc111b7705fe19b9b4ddee3e6a317a23 100644 (file)
@@ -1052,7 +1052,11 @@ alloc_encrypted:
                        if (ret < 0)
                                goto send_end;
                        tls_ctx->pending_open_record_frags = true;
-                       if (full_record || eor || sk_msg_full(msg_pl))
+
+                       if (sk_msg_full(msg_pl))
+                               full_record = true;
+
+                       if (full_record || eor)
                                goto copied;
                        continue;
                }