[syzbot] [udf?] possible deadlock in udf_free_blocks

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 0fc810ae3ae1 x86/uaccess: Avoid barrier_nospec() in 64-bit..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1106e55f980000
kernel config: https://syzkaller.appspot.com/x/.config?x=4aec7739e14231a7
dashboard link: https://syzkaller.appspot.com/bug?extid=d472c32c5dd4cd2fb5c5
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-0fc810ae.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/35cb2385689e/vmlinux-0fc810ae.xz
kernel image: https://storage.googleapis.com/syzbot-assets/32b7d90faa74/bzImage-0fc810ae.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+d472c3...@syzkaller.appspotmail.com

loop0: detected capacity change from 0 to 2048
=======================================================
WARNING: The mand mount option has been deprecated and
and is ignored by this kernel. Remove the mand
option from the mount to silence this warning.
=======================================================
UDF-fs: error (device loop0): udf_read_tagged: tag checksum failed, block 99: 0x27 != 0x4d
UDF-fs: error (device loop0): udf_read_tagged: tag checksum failed, block 160: 0xd2 != 0xd4
UDF-fs: INFO Mounting volume 'LinuxUDF', timestamp 2022/11/22 14:59 (1000)
============================================
WARNING: possible recursive locking detected
6.12.0-rc5-syzkaller-00063-g0fc810ae3ae1 #0 Not tainted
--------------------------------------------
syz.0.0/5328 is trying to acquire lock:
ffff8880432e6128 (&sbi->s_alloc_mutex){+.+.}-{3:3}, at: udf_table_free_blocks fs/udf/balloc.c:375 [inline]
ffff8880432e6128 (&sbi->s_alloc_mutex){+.+.}-{3:3}, at: udf_free_blocks+0x9ff/0x2270 fs/udf/balloc.c:677

but task is already holding lock:
ffff8880432e6128 (&sbi->s_alloc_mutex){+.+.}-{3:3}, at: udf_table_prealloc_blocks fs/udf/balloc.c:516 [inline]
ffff8880432e6128 (&sbi->s_alloc_mutex){+.+.}-{3:3}, at: udf_prealloc_blocks+0x820/0x13d0 fs/udf/balloc.c:701

other info that might help us debug this:
Possible unsafe locking scenario:

CPU0
----
lock(&sbi->s_alloc_mutex);
lock(&sbi->s_alloc_mutex);

*** DEADLOCK ***

May be due to missing lock nesting notation

4 locks held by syz.0.0/5328:
#0: ffff8880438b6420 (sb_writers#11){.+.+}-{0:0}, at: direct_splice_actor+0x49/0x220 fs/splice.c:1163
#1: ffff888043f24f60 (&sb->s_type->i_mutex_key#19){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:815 [inline]
#1: ffff888043f24f60 (&sb->s_type->i_mutex_key#19){+.+.}-{3:3}, at: udf_file_write_iter+0x6f/0x660 fs/udf/file.c:95
#2: ffff888043f24d90 (&ei->i_data_sem#2){++++}-{3:3}, at: udf_map_block+0x3b7/0x5340 fs/udf/inode.c:439
#3: ffff8880432e6128 (&sbi->s_alloc_mutex){+.+.}-{3:3}, at: udf_table_prealloc_blocks fs/udf/balloc.c:516 [inline]
#3: ffff8880432e6128 (&sbi->s_alloc_mutex){+.+.}-{3:3}, at: udf_prealloc_blocks+0x820/0x13d0 fs/udf/balloc.c:701

stack backtrace:
CPU: 0 UID: 0 PID: 5328 Comm: syz.0.0 Not tainted 6.12.0-rc5-syzkaller-00063-g0fc810ae3ae1 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
print_deadlock_bug+0x483/0x620 kernel/locking/lockdep.c:3037
check_deadlock kernel/locking/lockdep.c:3089 [inline]
validate_chain+0x15e2/0x5920 kernel/locking/lockdep.c:3891
__lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
__mutex_lock_common kernel/locking/mutex.c:608 [inline]
__mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
udf_table_free_blocks fs/udf/balloc.c:375 [inline]
udf_free_blocks+0x9ff/0x2270 fs/udf/balloc.c:677
udf_delete_aext+0x70a/0xed0 fs/udf/inode.c:2372
udf_table_prealloc_blocks fs/udf/balloc.c:543 [inline]
udf_prealloc_blocks+0xf2b/0x13d0 fs/udf/balloc.c:701
udf_prealloc_extents fs/udf/inode.c:1052 [inline]
inode_getblk fs/udf/inode.c:910 [inline]
udf_map_block+0x284a/0x5340 fs/udf/inode.c:447
__udf_get_block+0x126/0x410 fs/udf/inode.c:461
__block_write_begin_int+0x50c/0x1a70 fs/buffer.c:2121
block_write_begin+0x8f/0x120 fs/buffer.c:2231
udf_write_begin+0x104/0x350 fs/udf/inode.c:256
generic_perform_write+0x344/0x6d0 mm/filemap.c:4054
__generic_file_write_iter+0x1b5/0x230 mm/filemap.c:4152
udf_file_write_iter+0x2fc/0x660 fs/udf/file.c:111
iter_file_splice_write+0xbfa/0x1510 fs/splice.c:743
do_splice_from fs/splice.c:941 [inline]
direct_splice_actor+0x11b/0x220 fs/splice.c:1164
splice_direct_to_actor+0x586/0xc80 fs/splice.c:1108
do_splice_direct_actor fs/splice.c:1207 [inline]
do_splice_direct+0x289/0x3e0 fs/splice.c:1233
do_sendfile+0x561/0xe10 fs/read_write.c:1388
__do_sys_sendfile64 fs/read_write.c:1455 [inline]
__se_sys_sendfile64+0x17c/0x1e0 fs/read_write.c:1441
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe35557e719
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe35644a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007fe355735f80 RCX: 00007fe35557e719
RDX: 0000000000000000 RSI: 000000000000000a RDI: 000000000000000a
RBP: 00007fe3555f132e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000800000009 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fe355735f80 R15: 00007ffcceb987c8
</TASK>


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: cdd30ebb1b9f module: Convert symbol namespace to string li..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12eeb0df980000
kernel config: https://syzkaller.appspot.com/x/.config?x=91c852e3d1d7c1a6

dashboard link: https://syzkaller.appspot.com/bug?extid=d472c32c5dd4cd2fb5c5
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=117440f8580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1659b5e8580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/e7e1e116ea6e/disk-cdd30ebb.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/76410fd02a13/vmlinux-cdd30ebb.xz
kernel image: https://storage.googleapis.com/syzbot-assets/60bcdb55dd9c/bzImage-cdd30ebb.xz
mounted in repro #1: https://storage.googleapis.com/syzbot-assets/559ad34ed532/mount_0.gz
mounted in repro #2: https://storage.googleapis.com/syzbot-assets/90c832beabca/mount_9.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+d472c3...@syzkaller.appspotmail.com

============================================
WARNING: possible recursive locking detected

6.13.0-rc1-syzkaller-00002-gcdd30ebb1b9f #0 Not tainted
--------------------------------------------
syz-executor233/6288 is trying to acquire lock:
ffff888033753d28 (&sbi->s_alloc_mutex){+.+.}-{4:4}, at: udf_table_free_blocks fs/udf/balloc.c:375 [inline]
ffff888033753d28 (&sbi->s_alloc_mutex){+.+.}-{4:4}, at: udf_free_blocks+0x9ff/0x2270 fs/udf/balloc.c:677

but task is already holding lock:

ffff888033753d28 (&sbi->s_alloc_mutex){+.+.}-{4:4}, at: udf_table_new_block fs/udf/balloc.c:581 [inline]
ffff888033753d28 (&sbi->s_alloc_mutex){+.+.}-{4:4}, at: udf_new_block+0xf81/0x21c0 fs/udf/balloc.c:725

other info that might help us debug this:
Possible unsafe locking scenario:

CPU0
----
lock(&sbi->s_alloc_mutex);
lock(&sbi->s_alloc_mutex);

*** DEADLOCK ***

May be due to missing lock nesting notation

4 locks held by syz-executor233/6288:
#0: ffff88807972e420 (sb_writers#11){.+.+}-{0:0}, at: direct_splice_actor+0x49/0x220 fs/splice.c:1163
#1: ffff8880669baf40 (&sb->s_type->i_mutex_key#18){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:818 [inline]
#1: ffff8880669baf40 (&sb->s_type->i_mutex_key#18){+.+.}-{4:4}, at: udf_file_write_iter+0x6f/0x660 fs/udf/file.c:95
#2: ffff8880669bad70 (&ei->i_data_sem#2){++++}-{4:4}, at: udf_map_block+0x3b7/0x5340 fs/udf/inode.c:439
#3: ffff888033753d28 (&sbi->s_alloc_mutex){+.+.}-{4:4}, at: udf_table_new_block fs/udf/balloc.c:581 [inline]
#3: ffff888033753d28 (&sbi->s_alloc_mutex){+.+.}-{4:4}, at: udf_new_block+0xf81/0x21c0 fs/udf/balloc.c:725

stack backtrace:
CPU: 1 UID: 0 PID: 6288 Comm: syz-executor233 Not tainted 6.13.0-rc1-syzkaller-00002-gcdd30ebb1b9f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024

Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
print_deadlock_bug+0x483/0x620 kernel/locking/lockdep.c:3037
check_deadlock kernel/locking/lockdep.c:3089 [inline]
validate_chain+0x15e2/0x5920 kernel/locking/lockdep.c:3891

__lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
__mutex_lock_common kernel/locking/mutex.c:585 [inline]
__mutex_lock+0x1ac/0xee0 kernel/locking/mutex.c:735

udf_table_free_blocks fs/udf/balloc.c:375 [inline]
udf_free_blocks+0x9ff/0x2270 fs/udf/balloc.c:677
udf_delete_aext+0x70a/0xed0 fs/udf/inode.c:2372

udf_table_new_block fs/udf/balloc.c:645 [inline]
udf_new_block+0x18ba/0x21c0 fs/udf/balloc.c:725
inode_getblk fs/udf/inode.c:894 [inline]
udf_map_block+0x1c9a/0x5340 fs/udf/inode.c:447
__udf_get_block+0x126/0x410 fs/udf/inode.c:461
__block_write_begin_int+0x50c/0x1a70 fs/buffer.c:2116
block_write_begin+0x8f/0x120 fs/buffer.c:2226
udf_write_begin+0x104/0x350 fs/udf/inode.c:256
generic_perform_write+0x344/0x6d0 mm/filemap.c:4055
__generic_file_write_iter+0x1b5/0x230 mm/filemap.c:4153

udf_file_write_iter+0x2fc/0x660 fs/udf/file.c:111
iter_file_splice_write+0xbfa/0x1510 fs/splice.c:743
do_splice_from fs/splice.c:941 [inline]
direct_splice_actor+0x11b/0x220 fs/splice.c:1164
splice_direct_to_actor+0x586/0xc80 fs/splice.c:1108
do_splice_direct_actor fs/splice.c:1207 [inline]
do_splice_direct+0x289/0x3e0 fs/splice.c:1233

do_sendfile+0x564/0x8a0 fs/read_write.c:1363
__do_sys_sendfile64 fs/read_write.c:1424 [inline]
__se_sys_sendfile64+0x17c/0x1e0 fs/read_write.c:1410

do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

RIP: 0033:0x7f912262ca29
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 1f 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f9121dd6168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f91226b4708 RCX: 00007f912262ca29
RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000005
RBP: 00007f91226b4700 R08: 00007f9121dd66c0 R09: 0000000000000000
R10: 0000000800000009 R11: 0000000000000246 R12: 00007f91226b470c
R13: 0000000000000016 R14: 00007ffe6add21b0 R15: 00007ffe6add2298
</TASK>


---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

[syzbot]

syzbot has bisected this issue to:

commit 7908632f2927b65f7486ae6b67c24071666ba43f
Author: Maíra Canal <mca...@igalia.com>
Date: Thu Sep 14 10:19:02 2023 +0000

Revert "drm/vkms: Fix race-condition between the hrtimer and the atomic commit"

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=13dbe80f980000
start commit: cdd30ebb1b9f module: Convert symbol namespace to string li..
git tree: upstream
final oops: https://syzkaller.appspot.com/x/report.txt?x=103be80f980000
console output: https://syzkaller.appspot.com/x/log.txt?x=17dbe80f980000

kernel config: https://syzkaller.appspot.com/x/.config?x=91c852e3d1d7c1a6
dashboard link: https://syzkaller.appspot.com/bug?extid=d472c32c5dd4cd2fb5c5

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=117440f8580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1659b5e8580000

Reported-by: syzbot+d472c3...@syzkaller.appspotmail.com
Fixes: 7908632f2927 ("Revert "drm/vkms: Fix race-condition between the hrtimer and the atomic commit"")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

[Jan Kara]

On Tue 03-12-24 04:41:03, syzbot wrote:
> syzbot has bisected this issue to:
>
> commit 7908632f2927b65f7486ae6b67c24071666ba43f
> Author: Maíra Canal <mca...@igalia.com>
> Date: Thu Sep 14 10:19:02 2023 +0000
>
> Revert "drm/vkms: Fix race-condition between the hrtimer and the atomic commit"

This is obviously bogus. Apparently the reproducer is not quite reliable...
But I can see where's the problem in UDF code.

Honza

> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=13dbe80f980000
> start commit: cdd30ebb1b9f module: Convert symbol namespace to string li..
> git tree: upstream
> final oops: https://syzkaller.appspot.com/x/report.txt?x=103be80f980000
> console output: https://syzkaller.appspot.com/x/log.txt?x=17dbe80f980000
> kernel config: https://syzkaller.appspot.com/x/.config?x=91c852e3d1d7c1a6
> dashboard link: https://syzkaller.appspot.com/bug?extid=d472c32c5dd4cd2fb5c5
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=117440f8580000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1659b5e8580000
>
> Reported-by: syzbot+d472c3...@syzkaller.appspotmail.com
> Fixes: 7908632f2927 ("Revert "drm/vkms: Fix race-condition between the hrtimer and the atomic commit"")
>
> For information about bisection process see: https://goo.gl/tpsmEJ#bisection

--
Jan Kara <ja...@suse.com>
SUSE Labs, CR

[syzbot]

syzbot has bisected this issue to:

commit 7908632f2927b65f7486ae6b67c24071666ba43f
Author: Maíra Canal <mca...@igalia.com>
Date: Thu Sep 14 10:19:02 2023 +0000

Revert "drm/vkms: Fix race-condition between the hrtimer and the atomic commit"

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=13bfa544580000

start commit: cdd30ebb1b9f module: Convert symbol namespace to string li..
git tree: upstream

final oops: https://syzkaller.appspot.com/x/report.txt?x=107fa544580000
console output: https://syzkaller.appspot.com/x/log.txt?x=17bfa544580000