diff mbox series

[07/10] tailq: fix cast macro for null pointer

Message ID 20250619071037.37325-8-david.marchand@redhat.com (mailing list archive)
State Superseded
Delegated to: Thomas Monjalon
Headers
Series Run with UBSan in GHA |

Checks

Context Check Description
ci/checkpatch warning coding style issues

Commit Message

David Marchand June 19, 2025, 7:10 a.m. UTC 
Doing arithmetics with the NULL pointer is undefined.

Caught by UBSan:

../app/test/test_tailq.c:111:9: runtime error:
	member access within null pointer of type 'struct rte_tailq_head'

Fixes: f6b4f6c9c123 ("tailq: use a single cast macro")
Cc: stable@dpdk.org

Signed-off-by: David Marchand <david.marchand@redhat.com>
---
 lib/eal/include/rte_tailq.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Bruce Richardson June 20, 2025, 9:23 a.m. UTC | #1 
On Thu, Jun 19, 2025 at 09:10:33AM +0200, David Marchand wrote:
> Doing arithmetics with the NULL pointer is undefined.
> 
> Caught by UBSan:
> 
> ../app/test/test_tailq.c:111:9: runtime error:
> 	member access within null pointer of type 'struct rte_tailq_head'
> 
> Fixes: f6b4f6c9c123 ("tailq: use a single cast macro")
> Cc: stable@dpdk.org
> 
> Signed-off-by: David Marchand <david.marchand@redhat.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>
diff mbox series

Patch

diff --git a/lib/eal/include/rte_tailq.h b/lib/eal/include/rte_tailq.h
index 89f7ef2134..c23df77d96 100644
--- a/lib/eal/include/rte_tailq.h
+++ b/lib/eal/include/rte_tailq.h
@@ -54,7 +54,7 @@  struct rte_tailq_elem {
  * Return the first tailq entry cast to the right struct.
  */
 #define RTE_TAILQ_CAST(tailq_entry, struct_name) \
-	(struct struct_name *)&(tailq_entry)->tailq_head
+	(tailq_entry == NULL ? NULL : (struct struct_name *)&(tailq_entry)->tailq_head)
 
 /**
  * Utility macro to make looking up a tailqueue for a particular struct easier.