Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: bpf: must hold reference on net namespace BUG: KASAN: slab-use-after-free in __nf_unregister_net_hook+0x640/0x6b0 Read of size 8 at addr ffff8880106fe400 by task repro/72= bpf_nf_link_release+0xda/0x1e0 bpf_link_free+0x139/0x2d0 bpf_link_release+0x68/0x80 __fput+0x414/0xb60 Eric says: It seems that bpf was able to defer the __nf_unregister_net_hook() after exit()/close() time. Perhaps a netns reference is missing, because the netns has been dismantled/freed already. bpf_nf_link_attach() does : link->net = net; But I do not see a reference being taken on net. Add such a reference and release it after hook unreg. Note that I was unable to get syzbot reproducer to work, so I do not know if this resolves this splat.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
84601d6ee68ae820dec97450934797046d62db4b to < f41bd93b3e0508edc7ba820357f949071dcc0accaffected84601d6ee68ae820dec97450934797046d62db4b to < d0d7939543a1b3bb93af9a18d258a774daf8f162affected84601d6ee68ae820dec97450934797046d62db4b to < 1230fe7ad3974f7bf6c78901473e039b34d4fb1faffected
Linux Linux
Default version status: affected
6.4affected0 to < 6.4unaffected6.6.59 to ≤ 6.6.*unaffected6.11.6 to ≤ 6.11.*unaffected6.12 to ≤ *unaffected