Re: KASAN: use-after-free Read in __nf_hook_entries_try_shrink

[Eric Dumazet]

On Fri, Oct 18, 2024 at 9:00 AM Xia Chu <jiangmo9@xxxxxxxxx> wrote:
>
> Hi,
>
> We would like to report the following bug which has been found by our modified version of syzkaller.
>
> ======================================================
> description: KASAN: use-after-free Read in __nf_hook_entries_try_shrink
> affected file: net/netfilter/core.c
> kernel version: 5.8.0-rc4
> kernel commit: 0aea6d5c5be33ce94c16f9ab2f64de1f481f424b
> git tree: upstream
> kernel config: attached
> crash reproducer: attached
> ======================================================
> Crash log:
> BUG: KASAN: use-after-free in hooks_validate net/netfilter/core.c:177 [inline]
> BUG: KASAN: use-after-free in __nf_hook_entries_try_shrink+0x3c0/0x470 net/netfilter/core.c:260
> Read of size 4 at addr ffff888067fe4220 by task kworker/u4:2/126
>
> CPU: 1 PID: 126 Comm: kworker/u4:2 Tainted: G        W         5.8.0-rc4+ #1

This is an old version of linux, not supported.

What do you expect from us ?