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| author | Jesper Juhl <jj@chaosbits.net> | 2011-01-13 21:53:38 +0100 |
|---|---|---|
| committer | Sven Eckelmann <sven@narfation.org> | 2011-01-13 22:11:12 +0100 |
| commit | ed7809d9c41b514115ddffaa860694393c2016b3 (patch) | |
| tree | ef0e14d7477b2363f787ace24b683a439ea103f2 | |
| parent | 53320fe3bb1b1eef1aaff8dd47aae530ebeeb1e5 (diff) | |
| download | op-kernel-dev-ed7809d9c41b514115ddffaa860694393c2016b3.zip op-kernel-dev-ed7809d9c41b514115ddffaa860694393c2016b3.tar.gz | |
batman-adv: Even Batman should not dereference NULL pointers
There's a problem in net/batman-adv/unicast.c::frag_send_skb().
dev_alloc_skb() allocates memory and may fail, thus returning NULL. If
this happens we'll pass a NULL pointer on to skb_split() which in turn
hands it to skb_split_inside_header() from where it gets passed to
skb_put() that lets skb_tail_pointer() play with it and that function
dereferences it. And thus the bat dies.
While I was at it I also moved the call to dev_alloc_skb() above the
assignment to 'unicast_packet' since there's no reason to do that
assignment if the memory allocation fails.
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
| -rw-r--r-- | net/batman-adv/unicast.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/net/batman-adv/unicast.c b/net/batman-adv/unicast.c index dc2e28b..ee41fef 100644 --- a/net/batman-adv/unicast.c +++ b/net/batman-adv/unicast.c @@ -229,10 +229,12 @@ int frag_send_skb(struct sk_buff *skb, struct bat_priv *bat_priv, if (!bat_priv->primary_if) goto dropped; - unicast_packet = (struct unicast_packet *) skb->data; + frag_skb = dev_alloc_skb(data_len - (data_len / 2) + ucf_hdr_len); + if (!frag_skb) + goto dropped; + unicast_packet = (struct unicast_packet *) skb->data; memcpy(&tmp_uc, unicast_packet, uc_hdr_len); - frag_skb = dev_alloc_skb(data_len - (data_len / 2) + ucf_hdr_len); skb_split(skb, frag_skb, data_len / 2); if (my_skb_head_push(skb, ucf_hdr_len - uc_hdr_len) < 0 || |
