From: Mehdi Ben Hadj Khelifa <mehdi.benhadjkhelifa@gmail.com>
Date: Sat, 18 Oct 2025 21:38:13 +0000 (+0100)
Subject: blk-mq: use struct_size() in kmalloc()
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=e5a82249d88c7063c4ac998704b0ae5784013976;p=thirdparty%2Flinux.git

blk-mq: use struct_size() in kmalloc()

Change struct size calculation to use struct_size()
to align with new recommended practices[1] which quotes:
"Another common case to avoid is calculating the size of a structure with
a trailing array of others structures, as in:

header = kzalloc(sizeof(*header) + count * sizeof(*header->item),
                 GFP_KERNEL);

Instead, use the helper:

header = kzalloc(struct_size(header, item, count), GFP_KERNEL);"

Signed-off-by: Mehdi Ben Hadj Khelifa <mehdi.benhadjkhelifa@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c
index e0bed16485c34..97b69fbe26f6c 100644
--- a/block/blk-mq-sched.c
+++ b/block/blk-mq-sched.c
@@ -466,8 +466,7 @@ struct elevator_tags *blk_mq_alloc_sched_tags(struct blk_mq_tag_set *set,
 	else
 		nr_tags = nr_hw_queues;
 
-	et = kmalloc(sizeof(struct elevator_tags) +
-			nr_tags * sizeof(struct blk_mq_tags *), gfp);
+	et = kmalloc(struct_size(et, tags, nr_tags), gfp);
 	if (!et)
 		return NULL;