diff options
| author | Doron Roberts-Kedes <doronrk@fb.com> | 2018-04-11 15:05:16 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-04-12 21:54:59 -0400 |
| commit | 9d0c75bf6e03d9bf80c55b0f677dc9b982958fd5 (patch) | |
| tree | bb0a065e70bb7331987e4759f216ba24db4949a0 | |
| parent | 5ff9c1a3dd92d2d8eeea6bb15b3502cfcc0e26fa (diff) | |
strparser: Fix incorrect strp->need_bytes value.
strp_data_ready resets strp->need_bytes to 0 if strp_peek_len indicates
that the remainder of the message has been received. However,
do_strp_work does not reset strp->need_bytes to 0. If do_strp_work
completes a partial message, the value of strp->need_bytes will continue
to reflect the needed bytes of the previous message, causing
future invocations of strp_data_ready to return early if
strp->need_bytes is less than strp_peek_len. Resetting strp->need_bytes
to 0 in __strp_recv on handing a full message to the upper layer solves
this problem.
__strp_recv also calculates strp->need_bytes using stm->accum_len before
stm->accum_len has been incremented by cand_len. This can cause
strp->need_bytes to be equal to the full length of the message instead
of the full length minus the accumulated length. This, in turn, causes
strp_data_ready to return early, even when there is sufficient data to
complete the partial message. Incrementing stm->accum_len before using
it to calculate strp->need_bytes solves this problem.
Found while testing net/tls_sw recv path.
Fixes: 43a0c6751a322847 ("strparser: Stream parser for messages")
Signed-off-by: Doron Roberts-Kedes <doronrk@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/strparser/strparser.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/net/strparser/strparser.c b/net/strparser/strparser.c index b9283ce5cd85..805b139756db 100644 --- a/net/strparser/strparser.c +++ b/net/strparser/strparser.c @@ -296,9 +296,9 @@ static int __strp_recv(read_descriptor_t *desc, struct sk_buff *orig_skb, strp_start_timer(strp, timeo); } + stm->accum_len += cand_len; strp->need_bytes = stm->strp.full_len - stm->accum_len; - stm->accum_len += cand_len; stm->early_eaten = cand_len; STRP_STATS_ADD(strp->stats.bytes, cand_len); desc->count = 0; /* Stop reading socket */ @@ -321,6 +321,7 @@ static int __strp_recv(read_descriptor_t *desc, struct sk_buff *orig_skb, /* Hurray, we have a new message! */ cancel_delayed_work(&strp->msg_timer_work); strp->skb_head = NULL; + strp->need_bytes = 0; STRP_STATS_INCR(strp->stats.msgs); /* Give skb to upper layer */ @@ -410,9 +411,7 @@ void strp_data_ready(struct strparser *strp) return; if (strp->need_bytes) { - if (strp_peek_len(strp) >= strp->need_bytes) - strp->need_bytes = 0; - else + if (strp_peek_len(strp) < strp->need_bytes) return; } |