> Subject: [PATCH] eal/linux: unregister alarm callback before free ptr
>
> 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, and the interrupt thread can dereference the ptr after free
> is called when the main thread cleans up (from the alarm callback).
>
> 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.
>
> Bugzilla ID: 1683
>
> Signed-off-by: Rui Ferreira <rui.ferrei...@h-partners.com>
> ---
> .mailmap | 1 +
> lib/eal/linux/eal_alarm.c | 9 ++++++++-
> 2 files changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/.mailmap b/.mailmap
> index d8439b79ce..907c5ea967 100644
> --- a/.mailmap
> +++ b/.mailmap
> @@ -1332,6 +1332,7 @@ Rosen Xu <rosen...@altera.com> <rosen...@intel.com>
> Roy Franz <roy.fr...@cavium.com>
> Roy Pledge <roy.ple...@nxp.com>
> Roy Shterman <roy.shter...@vastdata.com>
> +Rui Ferreira <rui.ferrei...@h-partners.com>
> Ruifeng Wang <ruifeng.w...@arm.com>
> Rushil Gupta <rush...@google.com>
> Ryan E Hall <ryan.e.h...@intel.com>
> diff --git a/lib/eal/linux/eal_alarm.c b/lib/eal/linux/eal_alarm.c
> index b216a007a3..eb6a21d4f0 100644
> --- a/lib/eal/linux/eal_alarm.c
> +++ b/lib/eal/linux/eal_alarm.c
> @@ -57,7 +57,14 @@ static void eal_alarm_callback(void *arg);
> void
> rte_eal_alarm_cleanup(void)
> {
> - rte_intr_instance_free(intr_handle);
> + /* unregister callback using intr_handle in interrupt thread */
> + int ret = rte_intr_callback_unregister_sync(intr_handle,
> + eal_alarm_callback, (void *)-1);
> + if (ret >= 0) {
> + rte_intr_instance_free(intr_handle);
> + intr_handle = NULL;
> + handler_registered = 0;
> + }
> }
>
> int
> --
Acked-by: Konstantin Ananyev <konstantin.anan...@huawei.com>
As a nit: as it is a bug-fix, probably start with 'fix ..' in the subject.
Also "Fixes:" and probably " Cc: sta...@dpdk.org" needs to be added.
> 2.35.3
