Re: [syzbot] [fs?] possible deadlock in ovl_create_object (2)

[syzbot <syzbot+7cab6a19619f1b8efc00@syzkaller.appspotmail.com>]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
WARNING: ODEBUG bug in lookup_object_or_alloc

ODEBUG: object ffffc90007cdf850 is on stack ffffc90007cd8000, but NOT annotated.
------------[ cut here ]------------
1
WARNING: lib/debugobjects.c:672 at debug_object_is_on_stack lib/debugobjects.c:672 [inline], CPU#0: syz-executor162/6029
WARNING: lib/debugobjects.c:672 at lookup_object_or_alloc.part.0.cold+0x19/0x40 lib/debugobjects.c:705, CPU#0: syz-executor162/6029
Modules linked in:
CPU: 0 UID: 0 PID: 6029 Comm: syz-executor162 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:debug_object_is_on_stack lib/debugobjects.c:672 [inline]
RIP: 0010:lookup_object_or_alloc.part.0.cold+0x19/0x40 lib/debugobjects.c:705
Code: c4 60 5b 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc 83 c5 01 89 2d a0 1f 7d 1a 4c 89 e6 48 c7 c7 c0 39 62 8c e8 21 ae eb ff 90 <0f> 0b 90 e9 82 31 fe 03 83 c5 01 89 2d 7f 1f 7d 1a 49 39 c4 73 da
RSP: 0018:ffffc90007cdf6c0 EFLAGS: 00010082
RAX: 0000000000000050 RBX: ffff88802cb1d738 RCX: 0000000000000000
RDX: 0000000000000050 RSI: ffffffff81ea1339 RDI: fffff52000f9bec9
RBP: 0000000000000001 R08: 0000000000000007 R09: 0000000000000000
R10: 8000000000000001 R11: 0000000000000001 R12: ffffc90007cdf850
R13: ffff888034204b00 R14: 0000000000000000 R15: 0000000000000000
FS:  00005555811b5400(0000) GS:ffff8880d5b57000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555811b8778 CR3: 000000002bbd8000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 lookup_object_or_alloc lib/debugobjects.c:682 [inline]
 __debug_object_init+0x2a9/0x3d0 lib/debugobjects.c:798
 __init_work+0x51/0x60 kernel/workqueue.c:697
 block2mtd_setup_defer+0xd7/0x1d0 drivers/mtd/devices/block2mtd.c:504
 block2mtd_setup+0x9c/0x1e0 drivers/mtd/devices/block2mtd.c:529
 param_attr_store+0x199/0x300 kernel/params.c:591
 module_attr_store+0x58/0x80 kernel/params.c:906
 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145
 kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:345
 iter_file_splice_write+0x830/0x10b0 fs/splice.c:736
 do_splice_from fs/splice.c:936 [inline]
 do_splice+0x109c/0x1fa0 fs/splice.c:1349
 __do_splice+0x33b/0x370 fs/splice.c:1431
 __do_sys_splice fs/splice.c:1634 [inline]
 __se_sys_splice fs/splice.c:1616 [inline]
 __x64_sys_splice+0x187/0x250 fs/splice.c:1616
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa1c31b3437
Code: 48 89 fa 4c 89 df e8 98 1d 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffce5a2ac20 EFLAGS: 00000202 ORIG_RAX: 0000000000000113
RAX: ffffffffffffffda RBX: 00005555811b5400 RCX: 00007fa1c31b3437
RDX: 0000000000000005 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007fa1c31ec0fe R08: 0000000000000026 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00005555811b7770
R13: 0000000000000026 R14: 00007ffce5a2aca0 R15: 0000000000000002
 </TASK>


Tested on:

commit:         238650ef Merge tag 'powerpc-7.3-4' of git://git.kernel..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=143de115580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=8c5c3949d762a91f
dashboard link: https://syzkaller.appspot.com/bug?extid=7cab6a19619f1b8efc00
compiler:       gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
patch:          https://syzkaller.appspot.com/x/patch.diff?x=17ade115580000