Re: [PATCH 1/2] scan: fix invalid read when canceling an ongoing scan

James Prestwood
2024-09-03T11:44:56Z

Hi Daniel,

On 9/1/24 11:34 PM, Daniel Bond wrote:
> Hi,
>
> There was reported an issue reported in the Arch Linux issue tracker,
> which I also experienced on my hardware after upgrading iwd to version
> 2.20. What happens is that iwd constantly segfaults with messages like
> this:
>
> [ 279.974994] Code: 00 00 00 00 f3 0f 1e fa 55 48 89 e5 41 57 41 56
> 41 55 41 54 53 48 83 ec 18 48 89 4d c8 4c 89 45 c0 48 85 ff 0f 84 f3
> 00 00 00 <80> 7e 20 00 49 89 f5 0f 85 e6 00 00 00 48 83 fa 01 48 89 fb 49 89
> [ 280.685109] iwd[1648]: segfault at 32 ip 0000788413f05de6 sp
> 00007ffeb3d023d0 error 4 in libell.so.0.0.2[1ade6,788413efb000+57000]
> lik
> ely on CPU 1 (core 1, socket 0)
> [ 280.685125] Code: 00 00 00 00 f3 0f 1e fa 55 48 89 e5 41 57 41 56
> 41 55 41 54 53 48 83 ec 18 48 89 4d c8 4c 89 45 c0 48 85 ff 0f 84 f3
> 00 00 00 <80> 7e 20 00 49 89 f5 0f 85 e6 00 00 00 48 83 fa 01 48 89 fb 49 89
> [ 290.573368] iwd[1686]: segfault at 32 ip 00007c0b35d49de6 sp
> 00007fff86c509d0 error 4 in libell.so.0.0.2[1ade6,7c0b35d3f000+57000]
> lik
> ely on CPU 2 (core 0, socket 0)
>
> The issue seems to be resolved by checking that results->sr is set:
>
> - if (!results->sr->canceled)
> + if (results->sr && !results->sr->canceled)
The patch on the arch issue report looks good to me. Can we go ahead and
just send that patch with git send-email?
>
> More information reported in the arch linux gitlab issuetracker, under
> gitlab archlinux org /archlinux/packaging/packages/iwd/-/issues/5 .
>
> In advance, thanks.
>
> Br, Daniel Bond