syzbot


possible deadlock in ocfs2_read_virt_blocks

Status: upstream: reported on 2024/12/22 11:42
Reported-by: syzbot+3e2174c956a9427f8739@syzkaller.appspotmail.com
First crash: 8h52m, last: 8h52m
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream possible deadlock in ocfs2_read_virt_blocks ocfs2 1 101d 101d 0/28 auto-obsoleted due to no activity on 2024/12/21 05:39

Sample crash report:
======================================================
WARNING: possible circular locking dependency detected
5.15.175-syzkaller #0 Not tainted
------------------------------------------------------
syz.0.1772/8977 is trying to acquire lock:
ffff8880713b22e0 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_read_virt_blocks+0x2b3/0xa10 fs/ocfs2/extent_map.c:976

but task is already holding lock:
ffff88802a4f8990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x12b9/0x1570 fs/jbd2/transaction.c:462

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (jbd2_handle){++++}-{0:0}
:
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
       start_this_handle+0x12e1/0x1570 fs/jbd2/transaction.c:464
       jbd2__journal_start+0x2d1/0x5c0 fs/jbd2/transaction.c:521
       __ext4_journal_start_sb+0x175/0x370 fs/ext4/ext4_jbd2.c:105
       __ext4_journal_start fs/ext4/ext4_jbd2.h:326 [inline]
       ext4_dirty_inode+0x8b/0x100 fs/ext4/inode.c:6007
       __mark_inode_dirty+0x2fd/0xd60 fs/fs-writeback.c:2464
       generic_update_time fs/inode.c:1856 [inline]
       inode_update_time fs/inode.c:1869 [inline]
       touch_atime+0x3fa/0x680 fs/inode.c:1941
       file_accessed include/linux/fs.h:2523 [inline]
       ext4_file_mmap+0x18e/0x370 fs/ext4/file.c:763
       call_mmap include/linux/fs.h:2179 [inline]
       mmap_file+0x5a/0xb0 mm/util.c:1092
       __mmap_region mm/mmap.c:1784 [inline]
       mmap_region+0x1035/0x1870 mm/mmap.c:2921
       do_mmap+0x78d/0xe00 mm/mmap.c:1574
       vm_mmap_pgoff+0x1ca/0x2d0 mm/util.c:551
       ksys_mmap_pgoff+0x559/0x780 mm/mmap.c:1623
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #1 (&mm->mmap_lock){++++}-{3:3}:
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
       __might_fault+0xb4/0x110 mm/memory.c:5355
       _copy_to_user+0x28/0x130 lib/usercopy.c:35
       copy_to_user include/linux/uaccess.h:200 [inline]
       fiemap_fill_next_extent+0x231/0x410 fs/ioctl.c:144
       ocfs2_fiemap_inline fs/ocfs2/extent_map.c:725 [inline]
       ocfs2_fiemap+0xc1d/0xf80 fs/ocfs2/extent_map.c:762
       ioctl_fiemap fs/ioctl.c:219 [inline]
       do_vfs_ioctl+0x1934/0x2b70 fs/ioctl.c:814
       __do_sys_ioctl fs/ioctl.c:872 [inline]
       __se_sys_ioctl+0x81/0x160 fs/ioctl.c:860
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #0 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3053 [inline]
       check_prevs_add kernel/locking/lockdep.c:3172 [inline]
       validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788
       __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
       down_read+0x45/0x2e0 kernel/locking/rwsem.c:1498
       ocfs2_read_virt_blocks+0x2b3/0xa10 fs/ocfs2/extent_map.c:976
       ocfs2_read_dir_block+0x102/0x5b0 fs/ocfs2/dir.c:508
       ocfs2_dir_foreach_blk_el fs/ocfs2/dir.c:1829 [inline]
       ocfs2_dir_foreach_blk+0x2a8/0x1ba0 fs/ocfs2/dir.c:1915
       ocfs2_dir_foreach fs/ocfs2/dir.c:1925 [inline]
       ocfs2_empty_dir+0x1d1/0x8c0 fs/ocfs2/dir.c:2139
       ocfs2_rename+0x25d5/0x3ea0 fs/ocfs2/namei.c:1499
       vfs_rename+0xd32/0x10f0 fs/namei.c:4832
       do_renameat2+0xe0f/0x1700 fs/namei.c:4985
       __do_sys_rename fs/namei.c:5031 [inline]
       __se_sys_rename fs/namei.c:5029 [inline]
       __x64_sys_rename+0x82/0x90 fs/namei.c:5029
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

other info that might help us debug this:

Chain exists of:
  &ocfs2_file_ip_alloc_sem_key --> &mm->mmap_lock --> jbd2_handle

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(jbd2_handle);
                               lock(&mm->mmap_lock);
                               lock(jbd2_handle);
  lock(&ocfs2_file_ip_alloc_sem_key);

 *** DEADLOCK ***

7 locks held by syz.0.1772/8977:
 #0: ffff88807e34e460 (sb_writers#34){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 fs/namespace.c:377
 #1: ffff8880712e5108 (&type->i_mutex_dir_key#23/1){+.+.}-{3:3}, at: do_renameat2+0x67e/0x1700 fs/namei.c:4924
 #2: ffff8880713b2648 (&sb->s_type->i_mutex_key#39){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:789 [inline]
 #2: ffff8880713b2648 (&sb->s_type->i_mutex_key#39){+.+.}-{3:3}, at: vfs_rename+0x814/0x10f0 fs/namei.c:4797
 #3: ffff8880712e6d88 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:789 [inline]
 #3: ffff8880712e6d88 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]){+.+.}-{3:3}, at: ocfs2_lookup_lock_orphan_dir+0xfe/0x340 fs/ocfs2/namei.c:2116
 #4: ffff88807e34e650 (sb_internal#4){.+.+}-{0:0}, at: ocfs2_rename+0x1e36/0x3ea0 fs/ocfs2/namei.c:1488
 #5: ffff888060f20ce8 (&journal->j_trans_barrier){.+.+}-{3:3}, at: ocfs2_start_trans+0x3b7/0x6f0 fs/ocfs2/journal.c:352
 #6: ffff88802a4f8990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x12b9/0x1570 fs/jbd2/transaction.c:462

stack backtrace:
CPU: 1 PID: 8977 Comm: syz.0.1772 Not tainted 5.15.175-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 check_noncircular+0x2f8/0x3b0 kernel/locking/lockdep.c:2133
 check_prev_add kernel/locking/lockdep.c:3053 [inline]
 check_prevs_add kernel/locking/lockdep.c:3172 [inline]
 validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788
 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012
 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
 down_read+0x45/0x2e0 kernel/locking/rwsem.c:1498
 ocfs2_read_virt_blocks+0x2b3/0xa10 fs/ocfs2/extent_map.c:976
 ocfs2_read_dir_block+0x102/0x5b0 fs/ocfs2/dir.c:508
 ocfs2_dir_foreach_blk_el fs/ocfs2/dir.c:1829 [inline]
 ocfs2_dir_foreach_blk+0x2a8/0x1ba0 fs/ocfs2/dir.c:1915
 ocfs2_dir_foreach fs/ocfs2/dir.c:1925 [inline]
 ocfs2_empty_dir+0x1d1/0x8c0 fs/ocfs2/dir.c:2139
 ocfs2_rename+0x25d5/0x3ea0 fs/ocfs2/namei.c:1499
 vfs_rename+0xd32/0x10f0 fs/namei.c:4832
 do_renameat2+0xe0f/0x1700 fs/namei.c:4985
 __do_sys_rename fs/namei.c:5031 [inline]
 __se_sys_rename fs/namei.c:5029 [inline]
 __x64_sys_rename+0x82/0x90 fs/namei.c:5029
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f9af53d0d29
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:00007f9af3241038 EFLAGS: 00000246 ORIG_RAX: 0000000000000052
RAX: ffffffffffffffda RBX: 00007f9af55c0fa0 RCX: 00007f9af53d0d29
RDX: 0000000000000000 RSI: 0000000020000180 RDI: 0000000020000200
RBP: 00007f9af544caa8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f9af55c0fa0 R15: 00007ffc8aa151e8
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/12/22 11:42 linux-5.15.y 91786f140358 b4fbdbd4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ocfs2_read_virt_blocks
2024/12/22 11:42 linux-5.15.y 91786f140358 b4fbdbd4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ocfs2_read_virt_blocks
* Struck through repros no longer work on HEAD.