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authorMing Lei <ming.lei@redhat.com>2024-12-18 18:16:15 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2024-12-27 14:02:12 +0100
commitb5792c162dcf6197bf3d2de2be6c8169435b73d0 (patch)
tree817d29229c6eb86473ff0aaae34ad9e6177c8872 /block
parent0f289ba4e5ae2ff81c8954ab2bd371082cb8eddc (diff)
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block: avoid to reuse `hctx` not removed from cpuhp callback list
[ Upstream commit 85672ca9ceeaa1dcf2777a7048af5f4aee3fd02b ] 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: 22465bbac53c ("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> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'block')
-rw-r--r--block/blk-mq.c11
1 files changed, 10 insertions, 1 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 1030875a3e95..d5995021815d 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -4421,6 +4421,15 @@ struct gendisk *blk_mq_alloc_disk_for_queue(struct request_queue *q,
}
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(
struct blk_mq_tag_set *set, struct request_queue *q,
int hctx_idx, int node)
@@ -4430,7 +4439,7 @@ static struct blk_mq_hw_ctx *blk_mq_alloc_and_init_hctx(
/* reuse dead hctx first */
spin_lock(&q->unused_hctx_lock);
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;
break;
}