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: 610bfc6bc9
("batman-adv: Receive fragmented packets and merge")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
This commit is contained in:
parent
4ea33ef0f9
commit
248e23b50e
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@ -239,8 +239,10 @@ err_unlock:
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spin_unlock_bh(&chain->lock);
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err:
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if (!ret)
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if (!ret) {
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kfree(frag_entry_new);
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kfree_skb(skb);
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}
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return ret;
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}
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@ -313,7 +315,7 @@ free:
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*
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* There are three possible outcomes: 1) Packet is merged: Return true and
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* set *skb to merged packet; 2) Packet is buffered: Return true and set *skb
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* to NULL; 3) Error: Return false and leave skb as is.
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* to NULL; 3) Error: Return false and free skb.
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*
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* Return: true when packet is merged or buffered, false when skb is not not
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* used.
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@ -338,9 +340,9 @@ bool batadv_frag_skb_buffer(struct sk_buff **skb,
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goto out_err;
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out:
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*skb = skb_out;
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ret = true;
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out_err:
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*skb = skb_out;
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return ret;
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}
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