ACK: [SRU][F/J/L][PATCH 0/1] CVE-2023-3609

[Tim Gardner]

On 8/3/23 12:43 PM, Yuxuan Luo wrote:
> [Impact]
> A use-after-free vulnerability in the Linux kernel's net/sched: cls_u32
> component can be exploited to achieve local privilege escalation. If
> tcf_change_indev() fails, u32_set_parms() will immediately return an
> error after incrementing or decrementing the reference counter in
> tcf_bind_filter(). If an attacker can control the reference counter and
> set it to zero, they can cause the reference to be freed, leading to a
> use-after-free vulnerability.
> 
> [Backport]
> Clean cherry pick.
> 
> [Test]
> Smoke tested via adding an u32 filter to a dummy device using `tc`.
> 
> [Potential Regression]
> Expect very low regression.
> 
> Lee Jones (1):
>    net/sched: cls_u32: Fix reference counter leak leading to overflow
> 
>   net/sched/cls_u32.c | 18 ++++++++++--------
>   1 file changed, 10 insertions(+), 8 deletions(-)
> 
Acked-by: Tim Gardner <tim.gardner at canonical.com>
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Tim Gardner
Canonical, Inc