Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: revalidate bridge ports ebt_redirect_tg() dereferences br_port_get_rcu() return without a NULL check, causing a kernel panic when the bridge port has been removed between the original hook invocation and an NFQUEUE reinject. A mere NULL check isn't sufficient, however. As sashiko review points out userspace can not only remove the port from the bridge, it could also place the device in a different virtual device, e.g. macvlan. If this happens, we must drop the packet, there is no way for us to reinject it into the bridge path. Switch to _upper API, we don't need the bridge port structure. Also, this fix keeps another bug intact: Both nfnetlink_log and nfnetlink_queue use CONFIG_BRIDGE_NETFILTER too aggressive, which prevents certain logging features when queueing in bridge family: NETFILTER_FAMILY_BRIDGE can be enabled while the old CONFIG_BRIDGE_NETFILTER cruft is off. Fixes tag is a common ancestor, this was always broken.
Affected products
- Linux / Linuxf350a0a87374418635689471606454abc7beaa3a – 43330a1e8aace6b5a8de9aba127e9e394ab49b0f
- Linux / Linuxf350a0a87374418635689471606454abc7beaa3a – 4beffcd726e2a731cea4dc18e1fbc55c8d76f1a0
- Linux / Linuxf350a0a87374418635689471606454abc7beaa3a – d4b1301fd3c9e5e105fd3767c68bc4ba558bb228
- Linux / Linuxf350a0a87374418635689471606454abc7beaa3a – ccb9fd4b87538ccf19ccff78ee26700526d94867
- Linux / Linux2.6.36 – 2.6.36
- Linux / Linux0 – 2.6.36
- Linux / Linux6.12.94 – 6.12.*
- Linux / Linux6.18.36 – 6.18.*
- Linux / Linux7.0.13 – 7.0.*
- Linux / Linux7.1 – *
References
- MISChttps://git.kernel.org/stable/c/43330a1e8aace6b5a8de9aba127e9e394ab49b0f
- MISChttps://git.kernel.org/stable/c/4beffcd726e2a731cea4dc18e1fbc55c8d76f1a0
- MISChttps://git.kernel.org/stable/c/d4b1301fd3c9e5e105fd3767c68bc4ba558bb228
- MISChttps://git.kernel.org/stable/c/ccb9fd4b87538ccf19ccff78ee26700526d94867