[PATCH v2] fix eal/linux: unregister alarm callback before free

[Thomas Monjalon]

Hello,

Did you see the comment from David about fixing for Windows and FreeBSD at the same time?
I think you just need to apply the same logic in 3 different places.
If you cannot test all, that's OK to submit the changes without full coverage testing.

Thank you


22/05/2025 17:59, Rui Ferreira:
> This was flagged by Address sanitizer as a use after free. The
> intr_handle ptr is shared between the main thread and the interrupt
> thread. The interrupt thread can dereference the ptr after free (from
> the alarm callback). free is called when the main thread cleans up.
> 
> The interrupt thread never terminates (eal_intr_thread_main) so
> use rte_intr_callback_unregister_sync during cleanup to
> ensure the callback is removed before freeing the ptr.
> 
> To be more defensive clear out the pointer and registration
> variable if we can unregister.
> 
> rte_intr_callback_unregister_sync may (optionally) use traces
> so the alarm cleanup must happen before eal_trace_fini to avoid
> accessing freed memory.
> 
> Bugzilla ID: 1683
> 
> Signed-off-by: Rui Ferreira <rui.ferreira1 at h-partners.com>
> ---
>  .mailmap                  | 1 +
>  lib/eal/linux/eal.c       | 3 ++-
>  lib/eal/linux/eal_alarm.c | 9 ++++++++-
>  3 files changed, 11 insertions(+), 2 deletions(-)