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| author | Sven Eckelmann <sven@narfation.org> | 2017-02-12 11:26:33 +0100 |
|---|---|---|
| committer | Simon Wunderlich <sw@simonwunderlich.de> | 2017-02-21 18:33:15 +0100 |
| commit | 248e23b50e2da0753f3b5faa068939cbe9f8a75a (patch) | |
| tree | dd61bcea4eca5273277df11eb555329d5215f2dd /net/batman-adv | |
| parent | batman-adv: Decrease hardif refcnt on fragmentation send error (diff) | |
| download | linux-248e23b50e2da0753f3b5faa068939cbe9f8a75a.tar.xz linux-248e23b50e2da0753f3b5faa068939cbe9f8a75a.zip | |
batman-adv: Fix double free during fragment merge error
The function batadv_frag_skb_buffer was supposed not to consume the skbuff
on errors. This was followed in the helper function
batadv_frag_insert_packet when the skb would potentially be inserted in the
fragment queue. But it could happen that the next helper function
batadv_frag_merge_packets would try to merge the fragments and fail. This
results in a kfree_skb of all the enqueued fragments (including the just
inserted one). batadv_recv_frag_packet would detect the error in
batadv_frag_skb_buffer and try to free the skb again.
The behavior of batadv_frag_skb_buffer (and its helper
batadv_frag_insert_packet) must therefore be changed to always consume the
skbuff to have a common behavior and avoid the double kfree_skb.
Fixes: 610bfc6bc99b ("batman-adv: Receive fragmented packets and merge")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Diffstat (limited to 'net/batman-adv')
| -rw-r--r-- | net/batman-adv/fragmentation.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/net/batman-adv/fragmentation.c b/net/batman-adv/fragmentation.c index 0854ebd8613e..31e97e9aee0d 100644 --- a/net/batman-adv/fragmentation.c +++ b/net/batman-adv/fragmentation.c @@ -239,8 +239,10 @@ err_unlock: spin_unlock_bh(&chain->lock); err: - if (!ret) + if (!ret) { kfree(frag_entry_new); + kfree_skb(skb); + } return ret; } @@ -313,7 +315,7 @@ free: * * There are three possible outcomes: 1) Packet is merged: Return true and * set *skb to merged packet; 2) Packet is buffered: Return true and set *skb - * to NULL; 3) Error: Return false and leave skb as is. + * to NULL; 3) Error: Return false and free skb. * * Return: true when packet is merged or buffered, false when skb is not not * used. @@ -338,9 +340,9 @@ bool batadv_frag_skb_buffer(struct sk_buff **skb, goto out_err; out: - *skb = skb_out; ret = true; out_err: + *skb = skb_out; return ret; } |