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| author | Sven Eckelmann <sven@narfation.org> | 2022-04-16 14:51:10 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-05-18 10:47:24 +0300 |
| commit | 3915341a935f3397f65a01580dc3bfc4cdf53d14 (patch) | |
| tree | 5d523839f0b47dc9271dacc4bfed7cc331889e53 /net | |
| parent | 90659487578cd8a46636b4c507609af44c60a132 (diff) | |
| download | linux-3915341a935f3397f65a01580dc3bfc4cdf53d14.tar.xz | |
batman-adv: Don't skb_split skbuffs with frag_list
[ Upstream commit a063f2fba3fa633a599253b62561051ac185fa99 ]
The receiving interface might have used GRO to receive more fragments than
MAX_SKB_FRAGS fragments. In this case, these will not be stored in
skb_shinfo(skb)->frags but merged into the frag list.
batman-adv relies on the function skb_split to split packets up into
multiple smaller packets which are not larger than the MTU on the outgoing
interface. But this function cannot handle frag_list entries and is only
operating on skb_shinfo(skb)->frags. If it is still trying to split such an
skb and xmit'ing it on an interface without support for NETIF_F_FRAGLIST,
then validate_xmit_skb() will try to linearize it. But this fails due to
inconsistent information. And __pskb_pull_tail will trigger a BUG_ON after
skb_copy_bits() returns an error.
In case of entries in frag_list, just linearize the skb before operating on
it with skb_split().
Reported-by: Felix Kaechele <felix@kaechele.ca>
Fixes: c6c8fea29769 ("net: Add batman-adv meshing protocol")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Tested-by: Felix Kaechele <felix@kaechele.ca>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/batman-adv/fragmentation.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/net/batman-adv/fragmentation.c b/net/batman-adv/fragmentation.c index 0da90e73c79b..f33a7f7a1249 100644 --- a/net/batman-adv/fragmentation.c +++ b/net/batman-adv/fragmentation.c @@ -478,6 +478,17 @@ int batadv_frag_send_packet(struct sk_buff *skb, goto free_skb; } + /* GRO might have added fragments to the fragment list instead of + * frags[]. But this is not handled by skb_split and must be + * linearized to avoid incorrect length information after all + * batman-adv fragments were created and submitted to the + * hard-interface + */ + if (skb_has_frag_list(skb) && __skb_linearize(skb)) { + ret = -ENOMEM; + goto free_skb; + } + /* Create one header to be copied to all fragments */ frag_header.packet_type = BATADV_UNICAST_FRAG; frag_header.version = BATADV_COMPAT_VERSION; |