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.
Product status
f350a0a87374418635689471606454abc7beaa3a (git) before 43330a1e8aace6b5a8de9aba127e9e394ab49b0f
f350a0a87374418635689471606454abc7beaa3a (git) before 4beffcd726e2a731cea4dc18e1fbc55c8d76f1a0
f350a0a87374418635689471606454abc7beaa3a (git) before d4b1301fd3c9e5e105fd3767c68bc4ba558bb228
f350a0a87374418635689471606454abc7beaa3a (git) before ccb9fd4b87538ccf19ccff78ee26700526d94867
2.6.36
Any version before 2.6.36
6.12.94 (semver)
6.18.36 (semver)
7.0.13 (semver)
7.1 (original_commit_for_fix)
References
git.kernel.org/...c/43330a1e8aace6b5a8de9aba127e9e394ab49b0f
git.kernel.org/...c/4beffcd726e2a731cea4dc18e1fbc55c8d76f1a0
git.kernel.org/...c/d4b1301fd3c9e5e105fd3767c68bc4ba558bb228
git.kernel.org/...c/ccb9fd4b87538ccf19ccff78ee26700526d94867