[PATCH] stack: occasional crash due to uninitialized variable

[PATCH] stack: occasional crash due to uninitialized variable

[Andre Muezerie]

Variable "success" was not being initialized and there was a code
path where the last do/while loop in __rte_stack_lf_pop_elems
looked at the value of this variable before it was set to any.

Compiling with msvc resulted in stack_lf_autotest sometimes crashing.

The fix is to initialize the variable. This same fix was applied to
stack\rte_stack_lf_generic.h in the past but was missed here.

Fixes: 7e6e609939a8 ("stack: add C11 atomic implementation")
Cc: stable@dpdk.org

Signed-off-by: Andre Muezerie <andremue@linux.microsoft.com>
---
 lib/stack/rte_stack_lf_c11.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/stack/rte_stack_lf_c11.h b/lib/stack/rte_stack_lf_c11.h
index 60d46e963b..ee1c79c095 100644
--- a/lib/stack/rte_stack_lf_c11.h
+++ b/lib/stack/rte_stack_lf_c11.h
@@ -77,7 +77,7 @@ __rte_stack_lf_pop_elems(struct rte_stack_lf_list *list,
 {
 	struct rte_stack_lf_head old_head;
 	uint64_t len;
-	int success;
+	int success = 0;
 
 	/* Reserve num elements, if available */
 	len = rte_atomic_load_explicit(&list->len, rte_memory_order_relaxed);
-- 
2.47.2.vfs.0.1

Re: [PATCH] stack: occasional crash due to uninitialized variable

[David Marchand]

On Tue, Feb 4, 2025 at 2:24 AM Andre Muezerie
<andremue@linux.microsoft.com> wrote:
>
> Variable "success" was not being initialized and there was a code
> path where the last do/while loop in __rte_stack_lf_pop_elems
> looked at the value of this variable before it was set to any.
>
> Compiling with msvc resulted in stack_lf_autotest sometimes crashing.
>
> The fix is to initialize the variable. This same fix was applied to
> stack\rte_stack_lf_generic.h in the past but was missed here.
>
> Fixes: 7e6e609939a8 ("stack: add C11 atomic implementation")
> Cc: stable@dpdk.org
>
> Signed-off-by: Andre Muezerie <andremue@linux.microsoft.com>

Indeed, good catch.
Reviewed-by: David Marchand <david.marchand@redhat.com>


-- 
David Marchand