diff options
| author |   Chen Jun <chenjun102@huawei.com> | 2022-10-31 03:12:42 +0000 |
|---|---|---|
| committer |   Jens Axboe <axboe@kernel.dk> | 2022-10-31 08:30:47 -0600 |
| commit | 943f45b9399ed8b2b5190cbc797995edaa97f58f (patch) | |
| tree | 6bd29a3a2557e2b2b159532a1ad1f6e0d24464d1 | |
| parent | block: Fix possible memory leak for rq_wb on add_disk failure (diff) | |
| download | linux-dev-943f45b9399ed8b2b5190cbc797995edaa97f58f.tar.xz linux-dev-943f45b9399ed8b2b5190cbc797995edaa97f58f.zip | |
blk-mq: Fix kmemleak in blk_mq_init_allocated_queue
There is a kmemleak caused by modprobe null_blk.ko
unreferenced object 0xffff8881acb1f000 (size 1024):
comm "modprobe", pid 836, jiffies 4294971190 (age 27.068s)
hex dump (first 32 bytes):
00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00 .....N..........
ff ff ff ff ff ff ff ff 00 53 99 9e ff ff ff ff .........S......
backtrace:
[<000000004a10c249>] kmalloc_node_trace+0x22/0x60
[<00000000648f7950>] blk_mq_alloc_and_init_hctx+0x289/0x350
[<00000000af06de0e>] blk_mq_realloc_hw_ctxs+0x2fe/0x3d0
[<00000000e00c1872>] blk_mq_init_allocated_queue+0x48c/0x1440
[<00000000d16b4e68>] __blk_mq_alloc_disk+0xc8/0x1c0
[<00000000d10c98c3>] 0xffffffffc450d69d
[<00000000b9299f48>] 0xffffffffc4538392
[<0000000061c39ed6>] do_one_initcall+0xd0/0x4f0
[<00000000b389383b>] do_init_module+0x1a4/0x680
[<0000000087cf3542>] load_module+0x6249/0x7110
[<00000000beba61b8>] __do_sys_finit_module+0x140/0x200
[<00000000fdcfff51>] do_syscall_64+0x35/0x80
[<000000003c0f1f71>] entry_SYSCALL_64_after_hwframe+0x46/0xb0
That is because q->ma_ops is set to NULL before blk_release_queue is
called.
blk_mq_init_queue_data
blk_mq_init_allocated_queue
blk_mq_realloc_hw_ctxs
for (i = 0; i < set->nr_hw_queues; i++) {
old_hctx = xa_load(&q->hctx_table, i);
if (!blk_mq_alloc_and_init_hctx(.., i, ..)) [1]
if (!old_hctx)
break;
xa_for_each_start(&q->hctx_table, j, hctx, j)
blk_mq_exit_hctx(q, set, hctx, j); [2]
if (!q->nr_hw_queues) [3]
goto err_hctxs;
err_exit:
q->mq_ops = NULL; [4]
blk_put_queue
blk_release_queue
if (queue_is_mq(q)) [5]
blk_mq_release(q);
[1]: blk_mq_alloc_and_init_hctx failed at i != 0.
[2]: The hctxs allocated by [1] are moved to q->unused_hctx_list and
will be cleaned up in blk_mq_release.
[3]: q->nr_hw_queues is 0.
[4]: Set q->mq_ops to NULL.
[5]: queue_is_mq returns false due to [4]. And blk_mq_release
will not be called. The hctxs in q->unused_hctx_list are leaked.
To fix it, call blk_release_queue in exception path.
Fixes: 2f8f1336a48b ("blk-mq: always free hctx after request queue is freed")
Signed-off-by: Yuan Can <yuancan@huawei.com>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20221031031242.94107-1-chenjun102@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | block/blk-mq.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c index 75c8296b6feb..21cc7c2da0f9 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -4193,9 +4193,7 @@ int blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, return 0; err_hctxs: - xa_destroy(&q->hctx_table); - q->nr_hw_queues = 0; - blk_mq_sysfs_deinit(q); + blk_mq_release(q); err_poll: blk_stat_free_callback(q->poll_cb); q->poll_cb = NULL; |