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block: avoid to reuse hctx not removed from cpuhp callback list

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If the 'hctx' isn't removed from cpuhp callback list, we can't reuse it,
otherwise use-after-free may be triggered.

Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202412172217.b906db7c-lkp@intel.com
Tested-by: kernel test robot <oliver.sang@intel.com>
Fixes: 22465bbac5 ("blk-mq: move cpuhp callback registering out of q->sysfs_lock")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20241218101617.3275704-3-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Ming Lei 2024-12-18 18:16:15 +08:00 committed by Jens Axboe
parent 224749be6c
commit 85672ca9ce
1 changed files with 10 additions and 1 deletions
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11
block/blk-mq.c
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@ -4412,6 +4412,15 @@ struct gendisk *blk_mq_alloc_disk_for_queue(struct request_queue *q,
} }
EXPORT_SYMBOL(blk_mq_alloc_disk_for_queue); EXPORT_SYMBOL(blk_mq_alloc_disk_for_queue);
/*
* Only hctx removed from cpuhp list can be reused
*/
static bool blk_mq_hctx_is_reusable(struct blk_mq_hw_ctx *hctx)
{
return hlist_unhashed(&hctx->cpuhp_online) &&
hlist_unhashed(&hctx->cpuhp_dead);
}
static struct blk_mq_hw_ctx *blk_mq_alloc_and_init_hctx( static struct blk_mq_hw_ctx *blk_mq_alloc_and_init_hctx(
struct blk_mq_tag_set *set, struct request_queue *q, struct blk_mq_tag_set *set, struct request_queue *q,
int hctx_idx, int node) int hctx_idx, int node)
@ -4421,7 +4430,7 @@ static struct blk_mq_hw_ctx *blk_mq_alloc_and_init_hctx(
/* reuse dead hctx first */ /* reuse dead hctx first */
spin_lock(&q->unused_hctx_lock); spin_lock(&q->unused_hctx_lock);
list_for_each_entry(tmp, &q->unused_hctx_list, hctx_list) { list_for_each_entry(tmp, &q->unused_hctx_list, hctx_list) {
if (tmp->numa_node == node) { if (tmp->numa_node == node && blk_mq_hctx_is_reusable(tmp)) {
hctx = tmp; hctx = tmp;
break; break;
} }