Re: [PATCH v2] e1000: fix OOB in e1000_tbi_should_accept()

[Simon Horman]

+ Aleksandr

On Mon, Dec 01, 2025 at 11:40:58AM +0800, Guangshuo Li wrote:
> In e1000_tbi_should_accept() we read the last byte of the frame via
> 'data[length - 1]' to evaluate the TBI workaround. If the descriptor-
> reported length is zero or larger than the actual RX buffer size, this
> read goes out of bounds and can hit unrelated slab objects. The issue
> is observed from the NAPI receive path (e1000_clean_rx_irq):

...

> Fixes: 2037110c96d5 ("e1000: move tbi workaround code into helper function")
> Cc: stable@xxxxxxxxxxxxxxx
> Suggested-by: Tony Nguyen <tony.nguyen@xxxxxxxxx>
> Signed-off-by: Guangshuo Li <lgs201920130244@xxxxxxxxx>

> ---
> changelog:
> v2:
> - Keep declarations at the beginning of e1000_tbi_should_accept().
> - Move the last_byte assignment after the length bounds checks (suggested by Tony Nguyen)

I'm not sure that Tony's suggestions warrant a Suggested-by tag.
And perhaps Aleksandr's Reviewed-by tag should have been carried
over from v1: IMHO, I don't think the changes between v1 and v2
materially effect the review. But overall this looks good to me.

Reviewed-by: Simon Horman <horms@xxxxxxxxxx>