4.14-stable review patch. If anyone has any objections, please let me know.
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From: Doron Roberts-Kedes doronrk@fb.com
[ Upstream commit 9d0c75bf6e03d9bf80c55b0f677dc9b982958fd5 ]
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/strparser/strparser.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)
--- a/net/strparser/strparser.c +++ b/net/strparser/strparser.c @@ -296,9 +296,9 @@ static int __strp_recv(read_descriptor_t 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 /* 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 *s 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; }