diff options
author | Jakub Kicinski <jakub.kicinski@netronome.com> | 2019-11-27 23:16:41 +0300 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2019-11-29 09:40:29 +0300 |
commit | 031097d9e079e40dce401031d1012e83d80eaf01 (patch) | |
tree | 9319b9fecaa4f80d2bf1d5166dadeb6f4927eb47 /net/ipv4/tcp_bpf.c | |
parent | d10523d0b3d78153ee58d19853ced26c9004c8c4 (diff) | |
download | linux-031097d9e079e40dce401031d1012e83d80eaf01.tar.xz |
net: skmsg: fix TLS 1.3 crash with full sk_msg
TLS 1.3 started using the entry at the end of the SG array
for chaining-in the single byte content type entry. This mostly
works:
[ E E E E E E . . ]
^ ^
start end
E < content type
/
[ E E E E E E C . ]
^ ^
start end
(Where E denotes a populated SG entry; C denotes a chaining entry.)
If the array is full, however, the end will point to the start:
[ E E E E E E E E ]
^
start
end
And we end up overwriting the start:
E < content type
/
[ C E E E E E E E ]
^
start
end
The sg array is supposed to be a circular buffer with start and
end markers pointing anywhere. In case where start > end
(i.e. the circular buffer has "wrapped") there is an extra entry
reserved at the end to chain the two halves together.
[ E E E E E E . . l ]
(Where l is the reserved entry for "looping" back to front.
As suggested by John, let's reserve another entry for chaining
SG entries after the main circular buffer. Note that this entry
has to be pointed to by the end entry so its position is not fixed.
Examples of full messages:
[ E E E E E E E E . l ]
^ ^
start end
<---------------.
[ E E . E E E E E E l ]
^ ^
end start
Now the end will always point to an unused entry, so TLS 1.3
can always use it.
Fixes: 130b392c6cd6 ("net: tls: Add tls 1.3 support")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_bpf.c')
-rw-r--r-- | net/ipv4/tcp_bpf.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c index 8a56e09cfb0e..e38705165ac9 100644 --- a/net/ipv4/tcp_bpf.c +++ b/net/ipv4/tcp_bpf.c @@ -301,7 +301,7 @@ EXPORT_SYMBOL_GPL(tcp_bpf_sendmsg_redir); static int tcp_bpf_send_verdict(struct sock *sk, struct sk_psock *psock, struct sk_msg *msg, int *copied, int flags) { - bool cork = false, enospc = msg->sg.start == msg->sg.end; + bool cork = false, enospc = sk_msg_full(msg); struct sock *sk_redir; u32 tosend, delta = 0; int ret; |