Re: [PATCH net 4/4] ice: fix invalid check for empty list in ice_sched_assoc_vsi_to_agg()

[Leon Romanovsky <leon@kernel.org>]

On Tue, Mar 28, 2023 at 10:20:35AM -0700, Tony Nguyen wrote:
> From: Jakob Koschel <jkl820.git@gmail.com>
> 
> The code implicitly assumes that the list iterator finds a correct
> handle. If 'vsi_handle' is not found the 'old_agg_vsi_info' was
> pointing to an bogus memory location. For safety a separate list
> iterator variable should be used to make the != NULL check on
> 'old_agg_vsi_info' correct under any circumstances.
> 
> Additionally Linus proposed to avoid any use of the list iterator
> variable after the loop, in the attempt to move the list iterator
> variable declaration into the macro to avoid any potential misuse after
> the loop. Using it in a pointer comparison after the loop is undefined
> behavior and should be omitted if possible [1].
> 
> Fixes: 37c592062b16 ("ice: remove the VSI info from previous agg")
> Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1]
> Signed-off-by: Jakob Koschel <jkl820.git@gmail.com>
> Tested-by: Arpana Arland <arpanax.arland@intel.com> (A Contingent worker at Intel)
> Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
> ---
>  drivers/net/ethernet/intel/ice/ice_sched.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 

Thanks,
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>