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author | Jakub Kicinski <jakub.kicinski@netronome.com> | 2019-05-24 19:34:32 +0200 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2019-05-27 06:47:13 +0200 |
commit | 04b25a5411f966c2e586909a8496553b71876fae (patch) | |
tree | 18417d59629d044b2b0ce5f0a057e3c62643f1d6 /net/tls | |
parent | selftests/tls: test for lowat overshoot with multiple records (diff) | |
download | linux-04b25a5411f966c2e586909a8496553b71876fae.tar.xz linux-04b25a5411f966c2e586909a8496553b71876fae.zip |
net/tls: fix no wakeup on partial reads
When tls_sw_recvmsg() partially copies a record it pops that
record from ctx->recv_pkt and places it on rx_list.
Next iteration of tls_sw_recvmsg() reads from rx_list via
process_rx_list() before it enters the decryption loop.
If there is no more records to be read tls_wait_data()
will put the process on the wait queue and got to sleep.
This is incorrect, because some data was already copied
in process_rx_list().
In case of RPC connections process may never get woken up,
because peer also simply blocks in read().
I think this may also fix a similar issue when BPF is at
play, because after __tcp_bpf_recvmsg() returns some data
we subtract it from len and use continue to restart the
loop, but len could have just reached 0, so again we'd
sleep unnecessarily. That's added by:
commit d3b18ad31f93 ("tls: add bpf support to sk_msg handling")
Fixes: 692d7b5d1f91 ("tls: Fix recvmsg() to be able to peek across multiple records")
Reported-by: David Beckett <david.beckett@netronome.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Tested-by: David Beckett <david.beckett@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/tls')
-rw-r--r-- | net/tls/tls_sw.c | 8 |
1 files changed, 2 insertions, 6 deletions
diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c index fc13234db74a..960494f437ac 100644 --- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -1719,7 +1719,7 @@ int tls_sw_recvmsg(struct sock *sk, len = len - copied; timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); - do { + while (len && (decrypted + copied < target || ctx->recv_pkt)) { bool retain_skb = false; bool zc = false; int to_decrypt; @@ -1850,11 +1850,7 @@ pick_next_record: } else { break; } - - /* If we have a new message from strparser, continue now. */ - if (decrypted + copied >= target && !ctx->recv_pkt) - break; - } while (len); + } recv_end: if (num_async) { |