WARNING in blkdev_put

Status: upstream: reported on 2026/08/17 10:21
Reported-by: syzbot+1656cb10c8b70c37e243@syzkaller.appspotmail.com
First crash: 7d08h, last: 6d22h
Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in blkdev_put fs -1 syz done error 2 2346d 2992d 0/29 auto-obsoleted due to no activity on 2022/09/16 19:00
upstream WARNING in blkdev_put (2) block -1 syz, C unreliable 250 1249d 1277d 22/29 fixed on 2023/06/08 14:41
android-49 WARNING in blkdev_put -1 syz, C 4 2967d 2689d 0/3 public: reported C repro on 2019/04/14 00:00
upstream WARNING in blkdev_put (3) block -1 syz, C done 377 1160d 1164d 23/29 fixed on 2023/09/28 17:51

Sample crash report:
RBP: 00007f9853a35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9853c26038 R14: 00007f9853c25fa0 R15: 00007ffd8ae2b258
 </TASK>
OOM killer enabled.
Restarting tasks ... done.
------------[ cut here ]------------
WARNING: CPU: 0 PID: 4470 at block/bdev.c:938 blkdev_put+0x639/0x780 block/bdev.c:938
Modules linked in:
CPU: 0 PID: 4470 Comm: syz.3.21 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:blkdev_put+0x639/0x780 block/bdev.c:938
Code: 2b dc fd 49 8b 3e e8 26 e4 77 fd 48 83 c3 48 48 89 df 48 83 c4 18 5b 41 5c 41 5d 41 5e 41 5f 5d e9 4c 67 1d 01 e8 d7 fe 8a fd <0f> 0b e9 54 fb ff ff e8 cb fe 8a fd 0f 0b e9 8d fb ff ff 48 8d 4b
RSP: 0018:ffffc900042d7c10 EFLAGS: 00010246
RAX: ffffffff83f72f49 RBX: ffff888148de8b00 RCX: 0000000000080000
RDX: ffffc9000e4aa000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: 00000000ffffffff R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200085af70 R12: dffffc0000000000
R13: 1ffff110291bd203 R14: ffff888143b69000 R15: 1ffff110291bd1f8
FS:  00007f34e2fa36c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9703a00218 CR3: 000000007bc41000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 software_resume+0x3e8/0x6a0 kernel/power/hibernate.c:1042
 resume_store+0xf7/0x1a0 kernel/power/hibernate.c:1205
 kernfs_fop_write_iter+0x3a0/0x520 fs/kernfs/file.c:352
 call_write_iter include/linux/fs.h:2265 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x482/0x9a0 fs/read_write.c:584
 ksys_write+0x14d/0x260 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f34e219e0d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f34e2fa3028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f34e2425fa0 RCX: 00007f34e219e0d9
RDX: 0000000000000003 RSI: 0000200000000040 RDI: 0000000000000005
RBP: 00007f34e2235024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f34e2426038 R14: 00007f34e2425fa0 R15: 00007ffff9e109d8
 </TASK>

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/17 20:10 linux-6.1.y e4f7d8be268e 905244d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in blkdev_put
2026/08/17 18:22 linux-6.1.y e4f7d8be268e 905244d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in blkdev_put
2026/08/17 10:21 linux-6.1.y e4f7d8be268e 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in blkdev_put
* Struck through repros no longer work on HEAD.