Re: [PATCH] [v2] qed: Fix a potential use-after-free in qed_cxt_tables_alloc

[Przemek Kitszel]

On 12/7/23 10:36, Dinghao Liu wrote:
> qed_ilt_shadow_alloc() will call qed_ilt_shadow_free() to
> free p_hwfn->p_cxt_mngr->ilt_shadow on error. However,
> qed_cxt_tables_alloc() accesses the freed pointer on failure
> of qed_ilt_shadow_alloc() through calling qed_cxt_mngr_free(),
> which may lead to use-after-free. Fix this issue by setting
> p_hwfn->p_cxt_mngr->ilt_shadow to NULL in qed_ilt_shadow_free().
>
> Fixes: fe56b9e6a8d9 ("qed: Add module with basic common support")
> Signed-off-by: Dinghao Liu <dinghao.liu@xxxxxxxxxx>
> ---
>
> Changelog:

For future submissions please also provide links to previous versions
(would be to v1 in this case). No need to add this now for this one.

> v2: -Change the bug type from double-free to use-after-free.
>      -Move the null check against p_mngr->ilt_shadow to the beginning
>       of the function qed_ilt_shadow_free().
>      -When kcalloc() fails in qed_ilt_shadow_alloc(), just return
>       because there is nothing to free.
> ---
>   drivers/net/ethernet/qlogic/qed/qed_cxt.c | 12 +++++++-----
>   1 file changed, 7 insertions(+), 5 deletions(-)


Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@xxxxxxxxx>