bisecting fixing commit since 0854ba5ff5c938307cd783e996b62c83f1ce923b
building syzkaller on 8b311eafa7f32ebcae67cdf5e16aa1ab3fc77e7f
testing commit 0854ba5ff5c938307cd783e996b62c83f1ce923b with gcc (GCC) 8.1.0
kernel signature: aeec2d9a6a55e56c811501f944fda9d3aab666f275071a2ff59e64a430bcd851
run #0: crashed: WARNING in blkdev_put
run #1: crashed: WARNING in __blkdev_put
run #2: crashed: kernel BUG at fs/block_dev.c:LINE!
run #3: crashed: WARNING in blkdev_put
run #4: crashed: WARNING in blkdev_put
run #5: crashed: WARNING in __blkdev_put
run #6: crashed: WARNING in blkdev_put
run #7: crashed: WARNING in __blkdev_put
run #8: OK
run #9: crashed: WARNING in blkdev_put
testing current HEAD 0a679e13ea30f85a1aef0669ee0c5a9fd7860b34
testing commit 0a679e13ea30f85a1aef0669ee0c5a9fd7860b34 with gcc (GCC) 8.1.0
kernel signature: 9edd4a2a2c71ff0eb2064b115c05a2f1321ed9429dde0c6cb812b5051e85325a
run #0: crashed: kernel BUG at fs/block_dev.c:LINE!
run #1: crashed: WARNING in blkdev_put
run #2: crashed: kernel BUG at fs/block_dev.c:LINE!
run #3: crashed: kernel BUG at fs/block_dev.c:LINE!
run #4: crashed: WARNING in __blkdev_put
run #5: OK
run #6: OK
run #7: OK
run #8: OK
run #9: OK
revisions tested: 2, total time: 35m5.290223193s (build: 11m47.797790633s, test: 22m33.008702399s)
the crash still happens on HEAD
commit msg: Merge branch 'for-5.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
crash: WARNING in __blkdev_put
 loop0: p1
 loop3: p1
 loop1: p1
__loop_clr_fd: partition scan of loop1 failed (rc=-16)
------------[ cut here ]------------
WARNING: CPU: 1 PID: 2338 at fs/block_dev.c:1888 bdput fs/block_dev.c:960 [inline]
WARNING: CPU: 1 PID: 2338 at fs/block_dev.c:1888 __blkdev_put+0x58e/0x690 fs/block_dev.c:1909
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 2338 Comm: syz-executor995 Not tainted 5.6.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x12d/0x187 lib/dump_stack.c:118
 panic+0x22a/0x4f5 kernel/panic.c:221
 __warn.cold.10+0x25/0x28 kernel/panic.c:582
 report_bug+0x1b0/0x270 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:174 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:267
 do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:286
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027
RIP: 0010:__blkdev_put+0x58e/0x690 fs/block_dev.c:1888
Code: ff 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 84 0e ff ff ff 48 8b bd 48 ff ff ff e8 e7 f8 e8 ff e9 fd fe ff ff <0f> 0b e9 cf fb ff ff 4c 89 e7 e8 b3 f8 e8 ff e9 7a fb ff ff 4c 89
RSP: 0018:ffff8881a9d5fcb0 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 1ffff110353abf9f RCX: 0000000000000000
RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff8881cc0643a8
RBP: ffff8881a9d5fda0 R08: ffffed103980c864 R09: ffffed103980c864
R10: ffff8881a9d5fca0 R11: ffff8881cc06431f R12: ffff8881cc064304
R13: 00000000080e001f R14: 00000000080e001f R15: ffff8881cc064300
 blkdev_put+0x73/0x480 fs/block_dev.c:1958
 blkdev_close+0x88/0xd0 fs/block_dev.c:1965
 __fput+0x25d/0x780 fs/file_table.c:280
 ____fput+0x9/0x10 fs/file_table.c:313
 task_work_run+0x10e/0x190 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x1be/0x210 arch/x86/entry/common.c:164
 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:278 [inline]
 do_syscall_64+0x50b/0x600 arch/x86/entry/common.c:304
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x401740
Code: 01 f0 ff ff 0f 83 80 0c 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 83 3d 8d 5f 2d 00 00 75 14 b8 03 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 54 0c 00 00 c3 48 83 ec 08 e8 ba 01 00 00
RSP: 002b:00007ffede475aa8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000401740
RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000003
RBP: 00000000000834a3 R08: 0000000000000000 R09: 000000000000000a
R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000402820
R13: 00000000004028b0 R14: 0000000000000000 R15: 0000000000000000
Kernel Offset: disabled
Rebooting in 86400 seconds..