syzbot


possible deadlock in f2fs_handle_error

Status: auto-obsoleted due to no activity on 2023/07/09 11:05
Reported-by: syzbot+ce62f2505197acb97356@syzkaller.appspotmail.com
First crash: 472d, last: 472d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream possible deadlock in f2fs_handle_error f2fs 80 484d 575d 0/27 auto-obsoleted due to no activity on 2023/06/25 13:29

Sample crash report:
loop4: detected capacity change from 0 to 131072
F2FS-fs (loop4): invalid crc value
F2FS-fs (loop4): Found nat_bits in checkpoint
F2FS-fs (loop4): f2fs_check_nid_range: out-of-range nid=2, run fsck to fix.
======================================================
WARNING: possible circular locking dependency detected
6.1.17-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.4/10081 is trying to acquire lock:
ffff88801f31c088 (&sbi->sb_lock){++++}-{3:3}, at: f2fs_down_write fs/f2fs/f2fs.h:2205 [inline]
ffff88801f31c088 (&sbi->sb_lock){++++}-{3:3}, at: f2fs_handle_error+0xeb/0x230 fs/f2fs/super.c:3898

but task is already holding lock:
ffff8880752ce130 (&nm_i->nat_tree_lock){++++}-{3:3}, at: f2fs_down_read fs/f2fs/f2fs.h:2180 [inline]
ffff8880752ce130 (&nm_i->nat_tree_lock){++++}-{3:3}, at: __f2fs_build_free_nids fs/f2fs/node.c:2479 [inline]
ffff8880752ce130 (&nm_i->nat_tree_lock){++++}-{3:3}, at: f2fs_build_free_nids+0x72a/0x1190 fs/f2fs/node.c:2527

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #5 (&nm_i->nat_tree_lock){++++}-{3:3}:
       lock_acquire+0x23a/0x630 kernel/locking/lockdep.c:5669
       down_read+0x39/0x50 kernel/locking/rwsem.c:1520
       f2fs_down_read fs/f2fs/f2fs.h:2180 [inline]
       f2fs_get_node_info+0xef/0x12c0 fs/f2fs/node.c:560
       __write_node_page+0x71f/0x2710 fs/f2fs/node.c:1612
       f2fs_sync_node_pages+0xec0/0x16d0 fs/f2fs/node.c:2016
       block_operations fs/f2fs/checkpoint.c:1270 [inline]
       f2fs_write_checkpoint+0xe51/0x1cd0 fs/f2fs/checkpoint.c:1650
       __write_checkpoint_sync fs/f2fs/checkpoint.c:1767 [inline]
       __checkpoint_and_complete_reqs+0xd6/0x3b0 fs/f2fs/checkpoint.c:1786
       issue_checkpoint_thread+0xd6/0x260 fs/f2fs/checkpoint.c:1817
       kthread+0x268/0x300 kernel/kthread.c:376
       ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306

-> #4 (&sbi->node_change){++++}-{3:3}:
       lock_acquire+0x23a/0x630 kernel/locking/lockdep.c:5669
       down_read+0x39/0x50 kernel/locking/rwsem.c:1520
       f2fs_vm_page_mkwrite+0x763/0x1410 fs/f2fs/file.c:116
       do_page_mkwrite+0x1a1/0x5f0 mm/memory.c:2973
       do_shared_fault mm/memory.c:4614 [inline]
       do_fault mm/memory.c:4682 [inline]
       handle_pte_fault mm/memory.c:4950 [inline]
       __handle_mm_fault mm/memory.c:5092 [inline]
       handle_mm_fault+0x22f0/0x5140 mm/memory.c:5213
       do_user_addr_fault arch/x86/mm/fault.c:1428 [inline]
       handle_page_fault arch/x86/mm/fault.c:1519 [inline]
       exc_page_fault+0x655/0x860 arch/x86/mm/fault.c:1575
       asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570

-> #3 (mapping.invalidate_lock#4){.+.+}-{3:3}:
       lock_acquire+0x23a/0x630 kernel/locking/lockdep.c:5669
       down_read+0x39/0x50 kernel/locking/rwsem.c:1520
       filemap_invalidate_lock_shared include/linux/fs.h:811 [inline]
       f2fs_vm_page_mkwrite+0x543/0x1410 fs/f2fs/file.c:104
       do_page_mkwrite+0x1a1/0x5f0 mm/memory.c:2973
       do_shared_fault mm/memory.c:4614 [inline]
       do_fault mm/memory.c:4682 [inline]
       handle_pte_fault mm/memory.c:4950 [inline]
       __handle_mm_fault mm/memory.c:5092 [inline]
       handle_mm_fault+0x22f0/0x5140 mm/memory.c:5213
       do_user_addr_fault arch/x86/mm/fault.c:1428 [inline]
       handle_page_fault arch/x86/mm/fault.c:1519 [inline]
       exc_page_fault+0x655/0x860 arch/x86/mm/fault.c:1575
       asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570

-> #2 (sb_pagefaults#2){.+.+}-{0:0}:
       lock_acquire+0x23a/0x630 kernel/locking/lockdep.c:5669
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write+0x58/0x1c0 include/linux/fs.h:1832
       sb_start_pagefault include/linux/fs.h:1936 [inline]
       f2fs_vm_page_mkwrite+0x477/0x1410 fs/f2fs/file.c:99
       do_page_mkwrite+0x1a1/0x5f0 mm/memory.c:2973
       do_shared_fault mm/memory.c:4614 [inline]
       do_fault mm/memory.c:4682 [inline]
       handle_pte_fault mm/memory.c:4950 [inline]
       __handle_mm_fault mm/memory.c:5092 [inline]
       handle_mm_fault+0x22f0/0x5140 mm/memory.c:5213
       do_user_addr_fault arch/x86/mm/fault.c:1428 [inline]
       handle_page_fault arch/x86/mm/fault.c:1519 [inline]
       exc_page_fault+0x655/0x860 arch/x86/mm/fault.c:1575
       asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570

-> #1 (&mm->mmap_lock#2){++++}-{3:3}:
       lock_acquire+0x23a/0x630 kernel/locking/lockdep.c:5669
       __might_fault+0xb2/0x110 mm/memory.c:5641
       _copy_to_user+0x26/0x130 lib/usercopy.c:36
       copy_to_user include/linux/uaccess.h:169 [inline]
       f2fs_ioc_get_encryption_pwsalt fs/f2fs/file.c:2353 [inline]
       __f2fs_ioctl+0xb718/0xbdc0 fs/f2fs/file.c:4155
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:870 [inline]
       __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:856
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #0 (&sbi->sb_lock){++++}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3098 [inline]
       check_prevs_add kernel/locking/lockdep.c:3217 [inline]
       validate_chain+0x1667/0x58e0 kernel/locking/lockdep.c:3832
       __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5056
       lock_acquire+0x23a/0x630 kernel/locking/lockdep.c:5669
       down_write+0x36/0x60 kernel/locking/rwsem.c:1573
       f2fs_down_write fs/f2fs/f2fs.h:2205 [inline]
       f2fs_handle_error+0xeb/0x230 fs/f2fs/super.c:3898
       scan_nat_page fs/f2fs/node.c:2383 [inline]
       __f2fs_build_free_nids fs/f2fs/node.c:2489 [inline]
       f2fs_build_free_nids+0xcae/0x1190 fs/f2fs/node.c:2527
       f2fs_fill_super+0x53f9/0x7cb0 fs/f2fs/super.c:4308
       mount_bdev+0x26d/0x3a0 fs/super.c:1414
       legacy_get_tree+0xeb/0x180 fs/fs_context.c:610
       vfs_get_tree+0x88/0x270 fs/super.c:1544
       do_new_mount+0x28b/0xad0 fs/namespace.c:3040
       do_mount fs/namespace.c:3383 [inline]
       __do_sys_mount fs/namespace.c:3591 [inline]
       __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3568
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

other info that might help us debug this:

Chain exists of:
  &sbi->sb_lock --> &sbi->node_change --> &nm_i->nat_tree_lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&nm_i->nat_tree_lock);
                               lock(&sbi->node_change);
                               lock(&nm_i->nat_tree_lock);
  lock(&sbi->sb_lock);

 *** DEADLOCK ***

3 locks held by syz-executor.4/10081:
 #0: ffff8880541f00e0 (&type->s_umount_key#62/1){+.+.}-{3:3}, at: alloc_super+0x217/0x930 fs/super.c:228
 #1: ffff8880752ce2c8 (&nm_i->build_lock){+.+.}-{3:3}, at: f2fs_build_free_nids+0xc8/0x1190 fs/f2fs/node.c:2526
 #2: ffff8880752ce130 (&nm_i->nat_tree_lock){++++}-{3:3}, at: f2fs_down_read fs/f2fs/f2fs.h:2180 [inline]
 #2: ffff8880752ce130 (&nm_i->nat_tree_lock){++++}-{3:3}, at: __f2fs_build_free_nids fs/f2fs/node.c:2479 [inline]
 #2: ffff8880752ce130 (&nm_i->nat_tree_lock){++++}-{3:3}, at: f2fs_build_free_nids+0x72a/0x1190 fs/f2fs/node.c:2527

stack backtrace:
CPU: 1 PID: 10081 Comm: syz-executor.4 Not tainted 6.1.17-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2178
 check_prev_add kernel/locking/lockdep.c:3098 [inline]
 check_prevs_add kernel/locking/lockdep.c:3217 [inline]
 validate_chain+0x1667/0x58e0 kernel/locking/lockdep.c:3832
 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5056
 lock_acquire+0x23a/0x630 kernel/locking/lockdep.c:5669
 down_write+0x36/0x60 kernel/locking/rwsem.c:1573
 f2fs_down_write fs/f2fs/f2fs.h:2205 [inline]
 f2fs_handle_error+0xeb/0x230 fs/f2fs/super.c:3898
 scan_nat_page fs/f2fs/node.c:2383 [inline]
 __f2fs_build_free_nids fs/f2fs/node.c:2489 [inline]
 f2fs_build_free_nids+0xcae/0x1190 fs/f2fs/node.c:2527
 f2fs_fill_super+0x53f9/0x7cb0 fs/f2fs/super.c:4308
 mount_bdev+0x26d/0x3a0 fs/super.c:1414
 legacy_get_tree+0xeb/0x180 fs/fs_context.c:610
 vfs_get_tree+0x88/0x270 fs/super.c:1544
 do_new_mount+0x28b/0xad0 fs/namespace.c:3040
 do_mount fs/namespace.c:3383 [inline]
 __do_sys_mount fs/namespace.c:3591 [inline]
 __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3568
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fe4eea8d62a
Code: 48 c7 c2 b8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d2 e8 b8 04 00 00 0f 1f 84 00 00 00 00 00 49 89 ca b8 a5 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:00007fe4ef8d8f88 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00000000000105fb RCX: 00007fe4eea8d62a
RDX: 0000000020010600 RSI: 0000000020010640 RDI: 00007fe4ef8d8fe0
RBP: 00007fe4ef8d9020 R08: 00007fe4ef8d9020 R09: 0000000001008050
R10: 0000000001008050 R11: 0000000000000202 R12: 0000000020010600
R13: 0000000020010640 R14: 00007fe4ef8d8fe0 R15: 0000000020000000
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/03/11 11:05 linux-6.1.y 11585e2f8b9d 5205ef30 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in f2fs_handle_error
* Struck through repros no longer work on HEAD.