diff options
| author | Eric Dumazet <edumazet@google.com> | 2025-07-07 12:45:17 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-07-17 18:37:18 +0200 |
| commit | e0dd2e9729660f3f4fcb16e0aef87342911528ef (patch) | |
| tree | 77b02ee2f7a2b92362c980b2d3387b6700311d93 | |
| parent | fd67f52eea806747c196f394e07a6727cbbead6a (diff) | |
netfilter: flowtable: account for Ethernet header in nf_flow_pppoe_proto()
[ Upstream commit 18cdb3d982da8976b28d57691eb256ec5688fad2 ]
syzbot found a potential access to uninit-value in nf_flow_pppoe_proto()
Blamed commit forgot the Ethernet header.
BUG: KMSAN: uninit-value in nf_flow_offload_inet_hook+0x7e4/0x940 net/netfilter/nf_flow_table_inet.c:27
nf_flow_offload_inet_hook+0x7e4/0x940 net/netfilter/nf_flow_table_inet.c:27
nf_hook_entry_hookfn include/linux/netfilter.h:157 [inline]
nf_hook_slow+0xe1/0x3d0 net/netfilter/core.c:623
nf_hook_ingress include/linux/netfilter_netdev.h:34 [inline]
nf_ingress net/core/dev.c:5742 [inline]
__netif_receive_skb_core+0x4aff/0x70c0 net/core/dev.c:5837
__netif_receive_skb_one_core net/core/dev.c:5975 [inline]
__netif_receive_skb+0xcc/0xac0 net/core/dev.c:6090
netif_receive_skb_internal net/core/dev.c:6176 [inline]
netif_receive_skb+0x57/0x630 net/core/dev.c:6235
tun_rx_batched+0x1df/0x980 drivers/net/tun.c:1485
tun_get_user+0x4ee0/0x6b40 drivers/net/tun.c:1938
tun_chr_write_iter+0x3e9/0x5c0 drivers/net/tun.c:1984
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0xb4b/0x1580 fs/read_write.c:686
ksys_write fs/read_write.c:738 [inline]
__do_sys_write fs/read_write.c:749 [inline]
Reported-by: syzbot+bf6ed459397e307c3ad2@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/686bc073.a00a0220.c7b3.0086.GAE@google.com/T/#u
Fixes: 87b3593bed18 ("netfilter: flowtable: validate pppoe header")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Pablo Neira Ayuso <pablo@netfilter.org>
Link: https://patch.msgid.link/20250707124517.614489-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | include/net/netfilter/nf_flow_table.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/net/netfilter/nf_flow_table.h b/include/net/netfilter/nf_flow_table.h index b63d53bb9dd6..1a6fca013165 100644 --- a/include/net/netfilter/nf_flow_table.h +++ b/include/net/netfilter/nf_flow_table.h @@ -369,7 +369,7 @@ static inline __be16 __nf_flow_pppoe_proto(const struct sk_buff *skb) static inline bool nf_flow_pppoe_proto(struct sk_buff *skb, __be16 *inner_proto) { - if (!pskb_may_pull(skb, PPPOE_SES_HLEN)) + if (!pskb_may_pull(skb, ETH_HLEN + PPPOE_SES_HLEN)) return false; *inner_proto = __nf_flow_pppoe_proto(skb); |