8626c56c82
Zefir Kurtisi reported kernel panic with an openwrt specific patch. However, it turns out that mainline has a similar bug waiting to happen. Once NF_HOOK() returns the skb is in undefined state and must not be used. Moreover, the okfn must consume the skb to support async processing (NF_QUEUE). Current okfn in this spot doesn't consume it and caller assumes that NF_HOOK return value tells us if skb was freed or not, but thats wrong. It "works" because no in-tree user registers a NFPROTO_BRIDGE hook at LOCAL_IN that returns STOLEN or NF_QUEUE verdicts. Once we add NF_QUEUE support for nftables bridge this will break -- NF_QUEUE holds the skb for async processing, caller will erronoulsy return RX_HANDLER_PASS and on reinject netfilter will access free'd skb. Fix this by pushing skb up the stack in the okfn instead. NB: It also seems dubious to use LOCAL_IN while bypassing PRE_ROUTING completely in this case but this is how its been forever so it seems preferable to not change this. Cc: Felix Fietkau <nbd@openwrt.org> Cc: Zefir Kurtisi <zefir.kurtisi@neratec.com> Signed-off-by: Florian Westphal <fw@strlen.de> Tested-by: Zefir Kurtisi <zefir.kurtisi@neratec.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
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| .. | ||
| netfilter | ||
| Kconfig | ||
| Makefile | ||
| br.c | ||
| br_device.c | ||
| br_fdb.c | ||
| br_forward.c | ||
| br_if.c | ||
| br_input.c | ||
| br_ioctl.c | ||
| br_mdb.c | ||
| br_multicast.c | ||
| br_netfilter_hooks.c | ||
| br_netfilter_ipv6.c | ||
| br_netlink.c | ||
| br_nf_core.c | ||
| br_private.h | ||
| br_private_stp.h | ||
| br_stp.c | ||
| br_stp_bpdu.c | ||
| br_stp_if.c | ||
| br_stp_timer.c | ||
| br_sysfs_br.c | ||
| br_sysfs_if.c | ||
| br_vlan.c | ||