This is a note to let you know that I've just added the patch titled
blkcg: fix memory leak in blk_iolatency_init
to the 5.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
blkcg-fix-memory-leak-in-blk_iolatency_init.patch
and it can be found in the queue-5.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 29eeb1fbc41860c5d77240db729e19f42da13ecb
Author: Yanfei Xu <yanfei.xu@xxxxxxxxxxxxx>
Date: Wed Sep 15 15:24:26 2021 +0800
blkcg: fix memory leak in blk_iolatency_init
[ Upstream commit 6f5ddde41069fcd1f0993ec76c9dbbf9d021fd4d ]
BUG: memory leak
unreferenced object 0xffff888129acdb80 (size 96):
comm "syz-executor.1", pid 12661, jiffies 4294962682 (age 15.220s)
hex dump (first 32 bytes):
20 47 c9 85 ff ff ff ff 20 d4 8e 29 81 88 ff ff G...... ..)....
01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff82264ec8>] kmalloc include/linux/slab.h:591 [inline]
[<ffffffff82264ec8>] kzalloc include/linux/slab.h:721 [inline]
[<ffffffff82264ec8>] blk_iolatency_init+0x28/0x190 block/blk-iolatency.c:724
[<ffffffff8225b8c4>] blkcg_init_queue+0xb4/0x1c0 block/blk-cgroup.c:1185
[<ffffffff822253da>] blk_alloc_queue+0x22a/0x2e0 block/blk-core.c:566
[<ffffffff8223b175>] blk_mq_init_queue_data block/blk-mq.c:3100 [inline]
[<ffffffff8223b175>] __blk_mq_alloc_disk+0x25/0xd0 block/blk-mq.c:3124
[<ffffffff826a9303>] loop_add+0x1c3/0x360 drivers/block/loop.c:2344
[<ffffffff826a966e>] loop_control_get_free drivers/block/loop.c:2501 [inline]
[<ffffffff826a966e>] loop_control_ioctl+0x17e/0x2e0 drivers/block/loop.c:2516
[<ffffffff81597eec>] vfs_ioctl fs/ioctl.c:51 [inline]
[<ffffffff81597eec>] __do_sys_ioctl fs/ioctl.c:874 [inline]
[<ffffffff81597eec>] __se_sys_ioctl fs/ioctl.c:860 [inline]
[<ffffffff81597eec>] __x64_sys_ioctl+0xfc/0x140 fs/ioctl.c:860
[<ffffffff843fa745>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
[<ffffffff843fa745>] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
[<ffffffff84600068>] entry_SYSCALL_64_after_hwframe+0x44/0xae
Once blk_throtl_init() queue init failed, blkcg_iolatency_exit() will
not be invoked for cleanup. That leads a memory leak. Swap the
blk_throtl_init() and blk_iolatency_init() calls can solve this.
Reported-by: syzbot+01321b15cc98e6bf96d6@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 19688d7f9592 (block/blk-cgroup: Swap the blk_throtl_init() and blk_iolatency_init() calls)
Signed-off-by: Yanfei Xu <yanfei.xu@xxxxxxxxxxxxx>
Acked-by: Tejun Heo <tj@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20210915072426.4022924-1-yanfei.xu@xxxxxxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 31fe9be179d9..26446f97deee 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -1201,10 +1201,6 @@ int blkcg_init_queue(struct request_queue *q)
if (preloaded)
radix_tree_preload_end();
- ret = blk_iolatency_init(q);
- if (ret)
- goto err_destroy_all;
-
ret = blk_ioprio_init(q);
if (ret)
goto err_destroy_all;
@@ -1213,6 +1209,12 @@ int blkcg_init_queue(struct request_queue *q)
if (ret)
goto err_destroy_all;
+ ret = blk_iolatency_init(q);
+ if (ret) {
+ blk_throtl_exit(q);
+ goto err_destroy_all;
+ }
+
return 0;
err_destroy_all:
