Subject: Re: [PATCH] net/mlx5e: Fix slab-out-of-bounds in mlx5_query_nic_vport_mac_list()

From: Simon Horman <[email-masked]>
Date: Sun, 3 Dec 2023 17:50:15 +0000

On Thu, Nov 30, 2023 at 01:46:56AM -0800, Shifeng Li wrote:
> Out_sz that the size of out buffer is calculated using query_nic_vport
> _context_in structure when driver query the MAC list. However query_nic
> _vport_context_in structure is smaller than query_nic_vport_context_out.
> When allowed_list_size is greater than 96, calling ether_addr_copy() will
> trigger an slab-out-of-bounds.
> 
> [ 1170.055866] BUG: KASAN: slab-out-of-bounds in mlx5_query_nic_vport_mac_list+0x481/0x4d0 [mlx5_core]
> [ 1170.055869] Read of size 4 at addr ffff88bdbc57d912 by task kworker/u128:1/461
> [ 1170.055870]
> [ 1170.055932] Workqueue: mlx5_esw_wq esw_vport_change_handler [mlx5_core]
> [ 1170.055936] Call Trace:
> [ 1170.055949]  dump_stack+0x8b/0xbb
> [ 1170.055958]  print_address_description+0x6a/0x270
> [ 1170.055961]  kasan_report+0x179/0x2c0
> [ 1170.056061]  mlx5_query_nic_vport_mac_list+0x481/0x4d0 [mlx5_core]
> [ 1170.056162]  esw_update_vport_addr_list+0x2c5/0xcd0 [mlx5_core]
> [ 1170.056257]  esw_vport_change_handle_locked+0xd08/0x1a20 [mlx5_core]
> [ 1170.056377]  esw_vport_change_handler+0x6b/0x90 [mlx5_core]
> [ 1170.056381]  process_one_work+0x65f/0x12d0
> [ 1170.056383]  worker_thread+0x87/0xb50
> [ 1170.056390]  kthread+0x2e9/0x3a0
> [ 1170.056394]  ret_from_fork+0x1f/0x40
> 
> Fixes: e16aea2744ab ("net/mlx5: Introduce access functions to modify/query vport mac lists")
> Cc: Ding Hui <[email-masked]>
> Signed-off-by: Shifeng Li <[email-masked]>

Hi,

I am unsure how you calculated the 96 figure above.
But in any case I agree that the cited patch introduced
the mismatch that you describe.

Reviewed-by: Simon Horman <[email-masked]>