* [syzbot] possible deadlock in fscrypt_initialize
@ 2022-04-21 1:05 syzbot
2022-04-21 1:42 ` Eric Biggers
0 siblings, 1 reply; 2+ messages in thread
From: syzbot @ 2022-04-21 1:05 UTC (permalink / raw)
To: ebiggers, jaegeuk, linux-fscrypt, linux-kernel, syzkaller-bugs, tytso
Hello,
syzbot found the following issue on:
HEAD commit: 90ea17a9e27b Merge tag 'scsi-fixes' of git://git.kernel.or..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16bf09d0f00000
kernel config: https://syzkaller.appspot.com/x/.config?x=ac042ae170e2c50f
dashboard link: https://syzkaller.appspot.com/bug?extid=1a748d0007eeac3ab079
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
Unfortunately, I don't have any reproducer for this issue yet.
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+1a748d0007eeac3ab079@syzkaller.appspotmail.com
======================================================
WARNING: possible circular locking dependency detected
5.18.0-rc2-syzkaller-00291-g90ea17a9e27b #0 Not tainted
------------------------------------------------------
syz-executor.0/3694 is trying to acquire lock:
ffffffff8bf36428 (fscrypt_init_mutex){+.+.}-{3:3}, at: fscrypt_initialize+0x3c/0xa0 fs/crypto/crypto.c:324
but task is already holding lock:
ffff8880430c8990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0xfb4/0x14a0 fs/jbd2/transaction.c:461
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (jbd2_handle){++++}-{0:0}:
start_this_handle+0xfe7/0x14a0 fs/jbd2/transaction.c:463
jbd2__journal_start+0x399/0x930 fs/jbd2/transaction.c:520
__ext4_journal_start_sb+0x3a8/0x4a0 fs/ext4/ext4_jbd2.c:105
__ext4_journal_start fs/ext4/ext4_jbd2.h:326 [inline]
ext4_dirty_inode+0x9d/0x110 fs/ext4/inode.c:5932
__mark_inode_dirty+0x45b/0xfe0 fs/fs-writeback.c:2367
mark_inode_dirty_sync include/linux/fs.h:2329 [inline]
iput.part.0+0x57/0x820 fs/inode.c:1767
iput+0x58/0x70 fs/inode.c:1760
dentry_unlink_inode+0x2b1/0x460 fs/dcache.c:401
__dentry_kill+0x3c0/0x640 fs/dcache.c:607
shrink_dentry_list+0x23c/0x800 fs/dcache.c:1201
prune_dcache_sb+0xe7/0x140 fs/dcache.c:1282
super_cache_scan+0x336/0x590 fs/super.c:104
do_shrink_slab+0x42d/0xbd0 mm/vmscan.c:774
shrink_slab+0x17c/0x6f0 mm/vmscan.c:934
shrink_node_memcgs mm/vmscan.c:3100 [inline]
shrink_node+0x8b3/0x1df0 mm/vmscan.c:3221
shrink_zones mm/vmscan.c:3458 [inline]
do_try_to_free_pages+0x3b5/0x1700 mm/vmscan.c:3516
try_to_free_pages+0x2ac/0x840 mm/vmscan.c:3751
__perform_reclaim mm/page_alloc.c:4624 [inline]
__alloc_pages_direct_reclaim mm/page_alloc.c:4646 [inline]
__alloc_pages_slowpath.constprop.0+0xac7/0x20e0 mm/page_alloc.c:5046
__alloc_pages+0x412/0x500 mm/page_alloc.c:5421
__alloc_pages_node include/linux/gfp.h:587 [inline]
khugepaged_alloc_page+0xa0/0x170 mm/khugepaged.c:868
collapse_huge_page mm/khugepaged.c:1071 [inline]
khugepaged_scan_pmd mm/khugepaged.c:1357 [inline]
khugepaged_scan_mm_slot mm/khugepaged.c:2167 [inline]
khugepaged_do_scan mm/khugepaged.c:2248 [inline]
khugepaged+0x3474/0x66e0 mm/khugepaged.c:2293
kthread+0x2e9/0x3a0 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
-> #1 (fs_reclaim){+.+.}-{0:0}:
__fs_reclaim_acquire mm/page_alloc.c:4572 [inline]
fs_reclaim_acquire+0x115/0x160 mm/page_alloc.c:4586
might_alloc include/linux/sched/mm.h:254 [inline]
slab_pre_alloc_hook mm/slab.h:722 [inline]
slab_alloc_node mm/slab.c:3214 [inline]
kmem_cache_alloc_node_trace+0x48/0x5b0 mm/slab.c:3625
kmalloc_node include/linux/slab.h:599 [inline]
kzalloc_node include/linux/slab.h:725 [inline]
mempool_create_node mm/mempool.c:266 [inline]
mempool_create+0x4e/0xc0 mm/mempool.c:255
mempool_create_page_pool include/linux/mempool.h:107 [inline]
fscrypt_initialize+0x86/0xa0 fs/crypto/crypto.c:330
fscrypt_setup_encryption_info+0xef/0xf00 fs/crypto/keysetup.c:545
fscrypt_get_encryption_info+0x34a/0x3f0 fs/crypto/keysetup.c:654
fscrypt_setup_filename+0x238/0xec0 fs/crypto/fname.c:426
__fscrypt_prepare_lookup+0x28/0xf0 fs/crypto/hooks.c:102
fscrypt_prepare_lookup include/linux/fscrypt.h:898 [inline]
ext4_fname_prepare_lookup+0x2b1/0x330 fs/ext4/ext4.h:2770
ext4_lookup_entry fs/ext4/namei.c:1694 [inline]
ext4_lookup fs/ext4/namei.c:1769 [inline]
ext4_lookup+0x12d/0x730 fs/ext4/namei.c:1760
lookup_open.isra.0+0x9aa/0x1690 fs/namei.c:3308
open_last_lookups fs/namei.c:3400 [inline]
path_openat+0x9a2/0x2910 fs/namei.c:3606
do_filp_open+0x1aa/0x400 fs/namei.c:3636
do_sys_openat2+0x16d/0x4c0 fs/open.c:1213
do_sys_open fs/open.c:1229 [inline]
__do_sys_openat fs/open.c:1245 [inline]
__se_sys_openat fs/open.c:1240 [inline]
__x64_sys_openat+0x13f/0x1f0 fs/open.c:1240
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #0 (fscrypt_init_mutex){+.+.}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3065 [inline]
check_prevs_add kernel/locking/lockdep.c:3188 [inline]
validate_chain kernel/locking/lockdep.c:3803 [inline]
__lock_acquire+0x2ac6/0x56c0 kernel/locking/lockdep.c:5029
lock_acquire kernel/locking/lockdep.c:5641 [inline]
lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5606
__mutex_lock_common kernel/locking/mutex.c:600 [inline]
__mutex_lock+0x12f/0x12f0 kernel/locking/mutex.c:733
fscrypt_initialize+0x3c/0xa0 fs/crypto/crypto.c:324
fscrypt_setup_encryption_info+0xef/0xf00 fs/crypto/keysetup.c:545
fscrypt_get_encryption_info+0x34a/0x3f0 fs/crypto/keysetup.c:654
fscrypt_setup_filename+0x238/0xec0 fs/crypto/fname.c:426
ext4_fname_setup_filename+0x8d/0x240 fs/ext4/ext4.h:2751
ext4_find_entry+0x8c/0x170 fs/ext4/namei.c:1674
__ext4_unlink+0x92/0x920 fs/ext4/namei.c:3155
ext4_unlink+0x346/0x9e0 fs/ext4/namei.c:3231
vfs_unlink+0x351/0x920 fs/namei.c:4148
do_unlinkat+0x3c9/0x650 fs/namei.c:4216
__do_sys_unlink fs/namei.c:4264 [inline]
__se_sys_unlink fs/namei.c:4262 [inline]
__x64_sys_unlink+0xc6/0x110 fs/namei.c:4262
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
other info that might help us debug this:
Chain exists of:
fscrypt_init_mutex --> fs_reclaim --> jbd2_handle
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(jbd2_handle);
lock(fs_reclaim);
lock(jbd2_handle);
lock(fscrypt_init_mutex);
*** DEADLOCK ***
4 locks held by syz-executor.0/3694:
#0: ffff8880434f6460 (sb_writers#5){.+.+}-{0:0}, at: do_unlinkat+0x17f/0x650 fs/namei.c:4195
#1: ffff8880784f46c0 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:783 [inline]
#1: ffff8880784f46c0 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: do_unlinkat+0x269/0x650 fs/namei.c:4199
#2: ffff88801b236440 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: inode_lock include/linux/fs.h:748 [inline]
#2: ffff88801b236440 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: vfs_unlink+0xd5/0x920 fs/namei.c:4137
#3: ffff8880430c8990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0xfb4/0x14a0 fs/jbd2/transaction.c:461
stack backtrace:
CPU: 0 PID: 3694 Comm: syz-executor.0 Not tainted 5.18.0-rc2-syzkaller-00291-g90ea17a9e27b #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2145
check_prev_add kernel/locking/lockdep.c:3065 [inline]
check_prevs_add kernel/locking/lockdep.c:3188 [inline]
validate_chain kernel/locking/lockdep.c:3803 [inline]
__lock_acquire+0x2ac6/0x56c0 kernel/locking/lockdep.c:5029
lock_acquire kernel/locking/lockdep.c:5641 [inline]
lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5606
__mutex_lock_common kernel/locking/mutex.c:600 [inline]
__mutex_lock+0x12f/0x12f0 kernel/locking/mutex.c:733
fscrypt_initialize+0x3c/0xa0 fs/crypto/crypto.c:324
fscrypt_setup_encryption_info+0xef/0xf00 fs/crypto/keysetup.c:545
fscrypt_get_encryption_info+0x34a/0x3f0 fs/crypto/keysetup.c:654
fscrypt_setup_filename+0x238/0xec0 fs/crypto/fname.c:426
ext4_fname_setup_filename+0x8d/0x240 fs/ext4/ext4.h:2751
ext4_find_entry+0x8c/0x170 fs/ext4/namei.c:1674
__ext4_unlink+0x92/0x920 fs/ext4/namei.c:3155
ext4_unlink+0x346/0x9e0 fs/ext4/namei.c:3231
vfs_unlink+0x351/0x920 fs/namei.c:4148
do_unlinkat+0x3c9/0x650 fs/namei.c:4216
__do_sys_unlink fs/namei.c:4264 [inline]
__se_sys_unlink fs/namei.c:4262 [inline]
__x64_sys_unlink+0xc6/0x110 fs/namei.c:4262
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f7581288a27
Code: 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 57 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd33ea0ca8 EFLAGS: 00000206 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7581288a27
RDX: 00007ffd33ea0ce0 RSI: 00007ffd33ea0ce0 RDI: 00007ffd33ea0d70
RBP: 00007ffd33ea0d70 R08: 0000000000000001 R09: 00007ffd33ea0b40
R10: 0000555556665893 R11: 0000000000000206 R12: 00007f75812e21f8
R13: 00007ffd33ea1e70 R14: 0000555556665850 R15: 00007ffd33ea2f70
</TASK>
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [syzbot] possible deadlock in fscrypt_initialize
2022-04-21 1:05 [syzbot] possible deadlock in fscrypt_initialize syzbot
@ 2022-04-21 1:42 ` Eric Biggers
0 siblings, 0 replies; 2+ messages in thread
From: Eric Biggers @ 2022-04-21 1:42 UTC (permalink / raw)
To: syzbot
Cc: jaegeuk, linux-fscrypt, linux-kernel, syzkaller-bugs, tytso, linux-ext4
On Wed, Apr 20, 2022 at 06:05:24PM -0700, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 90ea17a9e27b Merge tag 'scsi-fixes' of git://git.kernel.or..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=16bf09d0f00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=ac042ae170e2c50f
> dashboard link: https://syzkaller.appspot.com/bug?extid=1a748d0007eeac3ab079
> compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
>
> Unfortunately, I don't have any reproducer for this issue yet.
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+1a748d0007eeac3ab079@syzkaller.appspotmail.com
>
> ======================================================
> WARNING: possible circular locking dependency detected
> 5.18.0-rc2-syzkaller-00291-g90ea17a9e27b #0 Not tainted
> ------------------------------------------------------
> syz-executor.0/3694 is trying to acquire lock:
> ffffffff8bf36428 (fscrypt_init_mutex){+.+.}-{3:3}, at: fscrypt_initialize+0x3c/0xa0 fs/crypto/crypto.c:324
>
> but task is already holding lock:
> ffff8880430c8990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0xfb4/0x14a0 fs/jbd2/transaction.c:461
This is a regression from a while back from the ext4 fast_commit changes,
specifically commit a80f7fcf1867 ("ext4: fixup ext4_fc_track_* functions'
signature") which extended the scope of the transaction in ext4_unlink() too
far. It's been on my TODO list to fix, along with the reports of fast_commit
and encryption not working together. I'll try to get to it soon.
- Eric
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2022-04-21 1:42 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-04-21 1:05 [syzbot] possible deadlock in fscrypt_initialize syzbot
2022-04-21 1:42 ` Eric Biggers
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.