Re: [syzbot] memory leak in blk_iolatency_init

From: syzbot
Date: Sat Oct 23 2021 - 14:58:40 EST

syzbot has found a reproducer for the following issue on:

HEAD commit: 9c0c4d24ac00 Merge tag 'block-5.15-2021-10-22' of git://gi..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1709f5c4b00000
kernel config: https://syzkaller.appspot.com/x/.config?x=d25eeb482b0f99b
dashboard link: https://syzkaller.appspot.com/bug?extid=01321b15cc98e6bf96d6
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=102280acb00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=144b96f8b00000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+01321b15cc98e6bf96d6@xxxxxxxxxxxxxxxxxxxxxxxxx

BUG: memory leak
unreferenced object 0xffff888104729800 (size 96):
comm "kworker/u4:2", pid 156, jiffies 4294937755 (age 219.670s)
hex dump (first 32 bytes):
00 49 c9 85 ff ff ff ff e0 b0 8b 03 81 88 ff ff .I..............
01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff82268cf8>] kmalloc include/linux/slab.h:591 [inline]
[<ffffffff82268cf8>] kzalloc include/linux/slab.h:721 [inline]
[<ffffffff82268cf8>] blk_iolatency_init+0x28/0x190 block/blk-iolatency.c:724
[<ffffffff8225f71e>] blkcg_init_queue+0xee/0x1c0 block/blk-cgroup.c:1193
[<ffffffff82228fca>] blk_alloc_queue+0x22a/0x2e0 block/blk-core.c:584
[<ffffffff8223ee35>] blk_mq_init_queue_data block/blk-mq.c:3119 [inline]
[<ffffffff8223ee35>] __blk_mq_alloc_disk+0x25/0xd0 block/blk-mq.c:3143
[<ffffffff826a187f>] floppy_alloc_disk+0x2f/0x130 drivers/block/floppy.c:4495
[<ffffffff86f2aaa9>] do_floppy_init drivers/block/floppy.c:4566 [inline]
[<ffffffff86f2aaa9>] floppy_async_init+0x10f/0x1329 drivers/block/floppy.c:4731
[<ffffffff81277354>] async_run_entry_fn+0x24/0xf0 kernel/async.c:127
[<ffffffff81265dbf>] process_one_work+0x2cf/0x620 kernel/workqueue.c:2297
[<ffffffff812666c9>] worker_thread+0x59/0x5d0 kernel/workqueue.c:2444
[<ffffffff8126fc48>] kthread+0x188/0x1d0 kernel/kthread.c:319
[<ffffffff810022cf>] ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

BUG: memory leak
unreferenced object 0xffff888104729400 (size 96):
comm "kworker/u4:2", pid 156, jiffies 4294937755 (age 219.670s)
hex dump (first 32 bytes):
00 49 c9 85 ff ff ff ff 90 a8 8b 03 81 88 ff ff .I..............
01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff82268cf8>] kmalloc include/linux/slab.h:591 [inline]
[<ffffffff82268cf8>] kzalloc include/linux/slab.h:721 [inline]
[<ffffffff82268cf8>] blk_iolatency_init+0x28/0x190 block/blk-iolatency.c:724
[<ffffffff8225f71e>] blkcg_init_queue+0xee/0x1c0 block/blk-cgroup.c:1193
[<ffffffff82228fca>] blk_alloc_queue+0x22a/0x2e0 block/blk-core.c:584
[<ffffffff8223ee35>] blk_mq_init_queue_data block/blk-mq.c:3119 [inline]
[<ffffffff8223ee35>] __blk_mq_alloc_disk+0x25/0xd0 block/blk-mq.c:3143
[<ffffffff826a187f>] floppy_alloc_disk+0x2f/0x130 drivers/block/floppy.c:4495
[<ffffffff86f2aaa9>] do_floppy_init drivers/block/floppy.c:4566 [inline]
[<ffffffff86f2aaa9>] floppy_async_init+0x10f/0x1329 drivers/block/floppy.c:4731
[<ffffffff81277354>] async_run_entry_fn+0x24/0xf0 kernel/async.c:127
[<ffffffff81265dbf>] process_one_work+0x2cf/0x620 kernel/workqueue.c:2297
[<ffffffff812666c9>] worker_thread+0x59/0x5d0 kernel/workqueue.c:2444
[<ffffffff8126fc48>] kthread+0x188/0x1d0 kernel/kthread.c:319
[<ffffffff810022cf>] ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

BUG: memory leak
unreferenced object 0xffff888104767e00 (size 96):
comm "kworker/u4:2", pid 156, jiffies 4294937755 (age 219.670s)
hex dump (first 32 bytes):
00 49 c9 85 ff ff ff ff 40 a0 8b 03 81 88 ff ff .I......@.......
01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff82268cf8>] kmalloc include/linux/slab.h:591 [inline]
[<ffffffff82268cf8>] kzalloc include/linux/slab.h:721 [inline]
[<ffffffff82268cf8>] blk_iolatency_init+0x28/0x190 block/blk-iolatency.c:724
[<ffffffff8225f71e>] blkcg_init_queue+0xee/0x1c0 block/blk-cgroup.c:1193
[<ffffffff82228fca>] blk_alloc_queue+0x22a/0x2e0 block/blk-core.c:584
[<ffffffff8223ee35>] blk_mq_init_queue_data block/blk-mq.c:3119 [inline]
[<ffffffff8223ee35>] __blk_mq_alloc_disk+0x25/0xd0 block/blk-mq.c:3143
[<ffffffff826a187f>] floppy_alloc_disk+0x2f/0x130 drivers/block/floppy.c:4495
[<ffffffff86f2aaa9>] do_floppy_init drivers/block/floppy.c:4566 [inline]
[<ffffffff86f2aaa9>] floppy_async_init+0x10f/0x1329 drivers/block/floppy.c:4731
[<ffffffff81277354>] async_run_entry_fn+0x24/0xf0 kernel/async.c:127
[<ffffffff81265dbf>] process_one_work+0x2cf/0x620 kernel/workqueue.c:2297
[<ffffffff812666c9>] worker_thread+0x59/0x5d0 kernel/workqueue.c:2444
[<ffffffff8126fc48>] kthread+0x188/0x1d0 kernel/kthread.c:319
[<ffffffff810022cf>] ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

BUG: memory leak
unreferenced object 0xffff888104767500 (size 96):
comm "kworker/u4:2", pid 156, jiffies 4294937755 (age 219.670s)
hex dump (first 32 bytes):
00 49 c9 85 ff ff ff ff 60 31 88 03 81 88 ff ff .I......`1......
01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff82268cf8>] kmalloc include/linux/slab.h:591 [inline]
[<ffffffff82268cf8>] kzalloc include/linux/slab.h:721 [inline]
[<ffffffff82268cf8>] blk_iolatency_init+0x28/0x190 block/blk-iolatency.c:724
[<ffffffff8225f71e>] blkcg_init_queue+0xee/0x1c0 block/blk-cgroup.c:1193
[<ffffffff82228fca>] blk_alloc_queue+0x22a/0x2e0 block/blk-core.c:584
[<ffffffff8223ee35>] blk_mq_init_queue_data block/blk-mq.c:3119 [inline]
[<ffffffff8223ee35>] __blk_mq_alloc_disk+0x25/0xd0 block/blk-mq.c:3143
[<ffffffff826a187f>] floppy_alloc_disk+0x2f/0x130 drivers/block/floppy.c:4495
[<ffffffff86f2aaa9>] do_floppy_init drivers/block/floppy.c:4566 [inline]
[<ffffffff86f2aaa9>] floppy_async_init+0x10f/0x1329 drivers/block/floppy.c:4731
[<ffffffff81277354>] async_run_entry_fn+0x24/0xf0 kernel/async.c:127
[<ffffffff81265dbf>] process_one_work+0x2cf/0x620 kernel/workqueue.c:2297
[<ffffffff812666c9>] worker_thread+0x59/0x5d0 kernel/workqueue.c:2444
[<ffffffff8126fc48>] kthread+0x188/0x1d0 kernel/kthread.c:319
[<ffffffff810022cf>] ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

write to /proc/sys/kernel/hung_task_check_interval_secs failed: No such file or directory
write to /proc/sys/kernel/softlockup_all_cpu_backtrace failed: No such file or directory
write to /proc/sys/kernel/hung_task_check_interval_secs failed: No such file or directory
write to /proc/sys/kernel/softlockup_all_cpu_backtrace failed: No such file or directory