syzbot


possible deadlock in __ocfs2_write_remove_suid

Status: upstream: reported on 2024/11/02 15:20
Subsystems: ocfs2
[Documentation on labels]
Reported-by: syzbot+61eb9f5be190a23ea4df@syzkaller.appspotmail.com
First crash: 45d, last: 45d
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [ocfs2?] possible deadlock in __ocfs2_write_remove_suid 0 (1) 2024/11/02 15:20

Sample crash report:
loop5: detected capacity change from 0 to 32768
ocfs2: Mounting device (7,5) on (node local, slot 0) with ordered data mode.
======================================================
WARNING: possible circular locking dependency detected
6.12.0-rc5-syzkaller-g1bf329c696cf #0 Not tainted
------------------------------------------------------
syz.5.170/7612 is trying to acquire lock:
ffff0000dfae4610 (sb_internal#4){.+.+}-{0:0}, at: __ocfs2_write_remove_suid+0x1ac/0x7b0 fs/ocfs2/file.c:1385

but task is already holding lock:
ffff0000ef3294a0 (&oi->ip_alloc_sem){++++}-{3:3}, at: ocfs2_inode_lock_for_extent_tree+0xf0/0x1cc fs/ocfs2/file.c:2202

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #4 (&oi->ip_alloc_sem){++++}-{3:3}:
       down_write+0x50/0xc0 kernel/locking/rwsem.c:1577
       ocfs2_try_remove_refcount_tree+0xb4/0x2f0 fs/ocfs2/refcounttree.c:932
       ocfs2_xattr_set+0x670/0x1448 fs/ocfs2/xattr.c:3670
       ocfs2_set_acl+0x410/0x4b4 fs/ocfs2/acl.c:254
       ocfs2_iop_set_acl+0x230/0x374 fs/ocfs2/acl.c:286
       set_posix_acl fs/posix_acl.c:955 [inline]
       vfs_set_acl+0x7a0/0xa24 fs/posix_acl.c:1134
       do_set_acl+0xc8/0x1ac fs/posix_acl.c:1279
       do_setxattr fs/xattr.c:626 [inline]
       path_setxattr+0x334/0x428 fs/xattr.c:658
       __do_sys_lsetxattr fs/xattr.c:683 [inline]
       __se_sys_lsetxattr fs/xattr.c:679 [inline]
       __arm64_sys_lsetxattr+0xbc/0xd8 fs/xattr.c:679
       __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
       invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
       el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
       do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
       el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744
       el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762
       el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600

-> #3 (&oi->ip_xattr_sem){++++}-{3:3}:
       down_read+0x58/0x2fc kernel/locking/rwsem.c:1524
       ocfs2_init_acl+0x2c8/0x764 fs/ocfs2/acl.c:366
       ocfs2_mknod+0x1388/0x243c fs/ocfs2/namei.c:408
       ocfs2_create+0x194/0x4e0 fs/ocfs2/namei.c:672
       lookup_open fs/namei.c:3595 [inline]
       open_last_lookups fs/namei.c:3694 [inline]
       path_openat+0x13e4/0x2b14 fs/namei.c:3930
       do_filp_open+0x1bc/0x3cc fs/namei.c:3960
       do_sys_openat2+0x124/0x1b8 fs/open.c:1415
       do_sys_open fs/open.c:1430 [inline]
       __do_sys_openat fs/open.c:1446 [inline]
       __se_sys_openat fs/open.c:1441 [inline]
       __arm64_sys_openat+0x1f0/0x240 fs/open.c:1441
       __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
       invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
       el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
       do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
       el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744
       el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762
       el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600

-> #2 (jbd2_handle){++++}-{0:0}:
       start_this_handle+0xf34/0x11c4 fs/jbd2/transaction.c:448
       jbd2__journal_start+0x298/0x544 fs/jbd2/transaction.c:505
       jbd2_journal_start+0x3c/0x4c fs/jbd2/transaction.c:544
       ocfs2_start_trans+0x3d0/0x71c fs/ocfs2/journal.c:352
       ocfs2_block_group_alloc fs/ocfs2/suballoc.c:685 [inline]
       ocfs2_reserve_suballoc_bits+0x840/0x4288 fs/ocfs2/suballoc.c:832
       ocfs2_reserve_new_metadata_blocks+0x384/0x848 fs/ocfs2/suballoc.c:982
       ocfs2_mknod+0xdc8/0x243c fs/ocfs2/namei.c:345
       ocfs2_create+0x194/0x4e0 fs/ocfs2/namei.c:672
       lookup_open fs/namei.c:3595 [inline]
       open_last_lookups fs/namei.c:3694 [inline]
       path_openat+0x13e4/0x2b14 fs/namei.c:3930
       do_filp_open+0x1bc/0x3cc fs/namei.c:3960
       do_sys_openat2+0x124/0x1b8 fs/open.c:1415
       do_sys_open fs/open.c:1430 [inline]
       __do_sys_openat fs/open.c:1446 [inline]
       __se_sys_openat fs/open.c:1441 [inline]
       __arm64_sys_openat+0x1f0/0x240 fs/open.c:1441
       __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
       invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
       el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
       do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
       el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744
       el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762
       el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600

-> #1 (&journal->j_trans_barrier){.+.+}-{3:3}:
       down_read+0x58/0x2fc kernel/locking/rwsem.c:1524
       ocfs2_start_trans+0x3c4/0x71c fs/ocfs2/journal.c:350
       ocfs2_block_group_alloc fs/ocfs2/suballoc.c:685 [inline]
       ocfs2_reserve_suballoc_bits+0x840/0x4288 fs/ocfs2/suballoc.c:832
       ocfs2_reserve_new_metadata_blocks+0x384/0x848 fs/ocfs2/suballoc.c:982
       ocfs2_mknod+0xdc8/0x243c fs/ocfs2/namei.c:345
       ocfs2_create+0x194/0x4e0 fs/ocfs2/namei.c:672
       lookup_open fs/namei.c:3595 [inline]
       open_last_lookups fs/namei.c:3694 [inline]
       path_openat+0x13e4/0x2b14 fs/namei.c:3930
       do_filp_open+0x1bc/0x3cc fs/namei.c:3960
       do_sys_openat2+0x124/0x1b8 fs/open.c:1415
       do_sys_open fs/open.c:1430 [inline]
       __do_sys_openat fs/open.c:1446 [inline]
       __se_sys_openat fs/open.c:1441 [inline]
       __arm64_sys_openat+0x1f0/0x240 fs/open.c:1441
       __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
       invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
       el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
       do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
       el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744
       el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762
       el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600

-> #0 (sb_internal#4){.+.+}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3161 [inline]
       check_prevs_add kernel/locking/lockdep.c:3280 [inline]
       validate_chain kernel/locking/lockdep.c:3904 [inline]
       __lock_acquire+0x33f8/0x77c8 kernel/locking/lockdep.c:5202
       lock_acquire+0x240/0x728 kernel/locking/lockdep.c:5825
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1716 [inline]
       sb_start_intwrite include/linux/fs.h:1899 [inline]
       ocfs2_start_trans+0x244/0x71c fs/ocfs2/journal.c:348
       __ocfs2_write_remove_suid+0x1ac/0x7b0 fs/ocfs2/file.c:1385
       ocfs2_write_remove_suid fs/ocfs2/file.c:1426 [inline]
       ocfs2_prepare_inode_for_write fs/ocfs2/file.c:2303 [inline]
       ocfs2_file_write_iter+0x8ac/0x1e10 fs/ocfs2/file.c:2441
       new_sync_write fs/read_write.c:590 [inline]
       vfs_write+0x920/0xcf4 fs/read_write.c:683
       ksys_write+0x15c/0x26c fs/read_write.c:736
       __do_sys_write fs/read_write.c:748 [inline]
       __se_sys_write fs/read_write.c:745 [inline]
       __arm64_sys_write+0x7c/0x90 fs/read_write.c:745
       __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
       invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
       el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
       do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
       el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744
       el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762
       el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600

other info that might help us debug this:

Chain exists of:
  sb_internal#4 --> &oi->ip_xattr_sem --> &oi->ip_alloc_sem

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  rlock(&oi->ip_alloc_sem);
                               lock(&oi->ip_xattr_sem);
                               lock(&oi->ip_alloc_sem);
  rlock(sb_internal#4);

 *** DEADLOCK ***

4 locks held by syz.5.170/7612:
 #0: ffff0000d1ba95f8 (&f->f_pos_lock){+.+.}-{3:3}, at: fdget_pos+0x214/0x2a0 fs/file.c:1160
 #1: ffff0000dfae4420 (sb_writers#19){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline]
 #1: ffff0000dfae4420 (sb_writers#19){.+.+}-{0:0}, at: vfs_write+0x354/0xcf4 fs/read_write.c:679
 #2: ffff0000ef329800 (&sb->s_type->i_mutex_key#26){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:815 [inline]
 #2: ffff0000ef329800 (&sb->s_type->i_mutex_key#26){+.+.}-{3:3}, at: ocfs2_file_write_iter+0x390/0x1e10 fs/ocfs2/file.c:2391
 #3: ffff0000ef3294a0 (&oi->ip_alloc_sem){++++}-{3:3}, at: ocfs2_inode_lock_for_extent_tree+0xf0/0x1cc fs/ocfs2/file.c:2202

stack backtrace:
CPU: 0 UID: 60928 PID: 7612 Comm: syz.5.170 Not tainted 6.12.0-rc5-syzkaller-g1bf329c696cf #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call trace:
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:484 (C)
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0xe4/0x150 lib/dump_stack.c:120
 dump_stack+0x1c/0x28 lib/dump_stack.c:129
 print_circular_bug+0x154/0x1c0 kernel/locking/lockdep.c:2074
 check_noncircular+0x310/0x404 kernel/locking/lockdep.c:2206
 check_prev_add kernel/locking/lockdep.c:3161 [inline]
 check_prevs_add kernel/locking/lockdep.c:3280 [inline]
 validate_chain kernel/locking/lockdep.c:3904 [inline]
 __lock_acquire+0x33f8/0x77c8 kernel/locking/lockdep.c:5202
 lock_acquire+0x240/0x728 kernel/locking/lockdep.c:5825
 percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
 __sb_start_write include/linux/fs.h:1716 [inline]
 sb_start_intwrite include/linux/fs.h:1899 [inline]
 ocfs2_start_trans+0x244/0x71c fs/ocfs2/journal.c:348
 __ocfs2_write_remove_suid+0x1ac/0x7b0 fs/ocfs2/file.c:1385
 ocfs2_write_remove_suid fs/ocfs2/file.c:1426 [inline]
 ocfs2_prepare_inode_for_write fs/ocfs2/file.c:2303 [inline]
 ocfs2_file_write_iter+0x8ac/0x1e10 fs/ocfs2/file.c:2441
 new_sync_write fs/read_write.c:590 [inline]
 vfs_write+0x920/0xcf4 fs/read_write.c:683
 ksys_write+0x15c/0x26c fs/read_write.c:736
 __do_sys_write fs/read_write.c:748 [inline]
 __se_sys_write fs/read_write.c:745 [inline]
 __arm64_sys_write+0x7c/0x90 fs/read_write.c:745
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744
 el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/10/29 15:11 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 1bf329c696cf 66aeb999 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 possible deadlock in __ocfs2_write_remove_suid
* Struck through repros no longer work on HEAD.