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| author | Jarek Poplawski <jarkao2@gmail.com> | 2008-02-17 22:31:19 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2008-02-17 22:31:19 -0800 |
| commit | f47b7257c7368698eabff6fd7b340071932af640 (patch) | |
| tree | d3733ff661cda7c00478348293810b3aeec6a1af /net/ax25 | |
| parent | 9bf1d83e7ee653862ef740435a7f41e8fd6452a9 (diff) | |
| download | linux-f47b7257c7368698eabff6fd7b340071932af640.tar.gz linux-f47b7257c7368698eabff6fd7b340071932af640.tar.bz2 linux-f47b7257c7368698eabff6fd7b340071932af640.zip | |
[AX25] ax25_out: check skb for NULL in ax25_kick()
According to some OOPS reports ax25_kick tries to clone NULL skbs
sometimes. It looks like a race with ax25_clear_queues(). Probably
there is no need to add more than a simple check for this yet.
Another report suggested there are probably also cases where ax25
->paclen == 0 can happen in ax25_output(); this wasn't confirmed
during testing but let's leave this debugging check for some time.
Reported-and-tested-by: Jann Traschewski <jann@gmx.de>
Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ax25')
| -rw-r--r-- | net/ax25/ax25_out.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/net/ax25/ax25_out.c b/net/ax25/ax25_out.c index 92b517af7260..bf706f83a5c9 100644 --- a/net/ax25/ax25_out.c +++ b/net/ax25/ax25_out.c @@ -117,6 +117,12 @@ void ax25_output(ax25_cb *ax25, int paclen, struct sk_buff *skb) unsigned char *p; int frontlen, len, fragno, ka9qfrag, first = 1; + if (paclen < 16) { + WARN_ON_ONCE(1); + kfree_skb(skb); + return; + } + if ((skb->len - 1) > paclen) { if (*skb->data == AX25_P_TEXT) { skb_pull(skb, 1); /* skip PID */ @@ -251,8 +257,6 @@ void ax25_kick(ax25_cb *ax25) if (start == end) return; - ax25->vs = start; - /* * Transmit data until either we're out of data to send or * the window is full. Send a poll on the final I frame if @@ -261,8 +265,13 @@ void ax25_kick(ax25_cb *ax25) /* * Dequeue the frame and copy it. + * Check for race with ax25_clear_queues(). */ skb = skb_dequeue(&ax25->write_queue); + if (!skb) + return; + + ax25->vs = start; do { if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) { |