Messages in this thread | | | Date | Mon, 16 Jan 2023 18:57:41 -0800 | Subject | [syzbot] [f2fs?] possible deadlock in __f2fs_ioctl (2) | From | syzbot <> |
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Hello,
syzbot found the following issue on:
HEAD commit: 5dc4c995db9e Linux 6.2-rc4 git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=11cc0da1480000 kernel config: https://syzkaller.appspot.com/x/.config?x=2d1e01fb80d3df97 dashboard link: https://syzkaller.appspot.com/bug?extid=0d79d79c510d77a7c661 compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/e52acf94631e/disk-5dc4c995.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/8ead5c940574/vmlinux-5dc4c995.xz kernel image: https://storage.googleapis.com/syzbot-assets/f6b43b71bf31/bzImage-5dc4c995.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+0d79d79c510d77a7c661@syzkaller.appspotmail.com
====================================================== WARNING: possible circular locking dependency detected 6.2.0-rc4-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.4/7644 is trying to acquire lock: ffff8880193935d8 (&mm->mmap_lock){++++}-{3:3}, at: __might_fault+0x8f/0x110 mm/memory.c:5646
but task is already holding lock: ffff88802babc088 (&sbi->sb_lock){++++}-{3:3}, at: f2fs_down_write fs/f2fs/f2fs.h:2213 [inline] ffff88802babc088 (&sbi->sb_lock){++++}-{3:3}, at: f2fs_ioc_get_encryption_pwsalt fs/f2fs/file.c:2350 [inline] ffff88802babc088 (&sbi->sb_lock){++++}-{3:3}, at: __f2fs_ioctl+0x3572/0xb540 fs/f2fs/file.c:4169
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #3 (&sbi->sb_lock){++++}-{3:3}: lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5668 down_write+0x9c/0x270 kernel/locking/rwsem.c:1562 f2fs_down_write fs/f2fs/f2fs.h:2213 [inline] f2fs_handle_error+0xe0/0x230 fs/f2fs/super.c:3926 scan_nat_page fs/f2fs/node.c:2387 [inline] __f2fs_build_free_nids fs/f2fs/node.c:2493 [inline] f2fs_build_free_nids+0xb8c/0x1190 fs/f2fs/node.c:2531 f2fs_fill_super+0x4a5f/0x6ee0 fs/f2fs/super.c:4334 mount_bdev+0x26c/0x3a0 fs/super.c:1359 legacy_get_tree+0xea/0x180 fs/fs_context.c:610 vfs_get_tree+0x88/0x270 fs/super.c:1489 do_new_mount+0x289/0xad0 fs/namespace.c:3145 do_mount fs/namespace.c:3488 [inline] __do_sys_mount fs/namespace.c:3697 [inline] __se_sys_mount+0x2d3/0x3c0 fs/namespace.c:3674 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
-> #2 (&nm_i->nat_tree_lock){++++}-{3:3}: lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5668 down_read+0x39/0x50 kernel/locking/rwsem.c:1509 f2fs_down_read fs/f2fs/f2fs.h:2188 [inline] f2fs_get_node_info+0x100/0x1720 fs/f2fs/node.c:564 f2fs_new_node_page+0x402/0xea0 fs/f2fs/node.c:1295 f2fs_get_dnode_of_data+0x5b0/0x1da0 fs/f2fs/node.c:810 f2fs_reserve_block+0x50/0x240 fs/f2fs/data.c:1199 f2fs_get_new_data_page+0x180/0x7b0 fs/f2fs/data.c:1387 f2fs_add_regular_entry+0x687/0xea0 fs/f2fs/dir.c:754 f2fs_add_dentry fs/f2fs/dir.c:816 [inline] f2fs_do_add_link+0x2a7/0x470 fs/f2fs/dir.c:855 f2fs_add_link fs/f2fs/f2fs.h:3564 [inline] f2fs_create+0x324/0x530 fs/f2fs/namei.c:363 lookup_open fs/namei.c:3413 [inline] open_last_lookups fs/namei.c:3481 [inline] path_openat+0x12ac/0x2dd0 fs/namei.c:3711 do_filp_open+0x264/0x4f0 fs/namei.c:3741 do_sys_openat2+0x124/0x4e0 fs/open.c:1310 do_sys_open fs/open.c:1326 [inline] __do_sys_creat fs/open.c:1402 [inline] __se_sys_creat fs/open.c:1396 [inline] __x64_sys_creat+0x11f/0x160 fs/open.c:1396 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
-> #1 (&sbi->cp_rwsem){++++}-{3:3}: lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5668 down_read+0x39/0x50 kernel/locking/rwsem.c:1509 f2fs_down_read fs/f2fs/f2fs.h:2188 [inline] f2fs_lock_op fs/f2fs/f2fs.h:2231 [inline] f2fs_convert_inline_inode+0x55f/0x820 fs/f2fs/inline.c:219 f2fs_vm_page_mkwrite+0x2d8/0x1350 fs/f2fs/file.c:79 do_page_mkwrite+0x19e/0x5e0 mm/memory.c:2947 wp_page_shared+0x15e/0x380 mm/memory.c:3295 handle_pte_fault mm/memory.c:4949 [inline] __handle_mm_fault mm/memory.c:5073 [inline] handle_mm_fault+0x1b79/0x26b0 mm/memory.c:5219 do_user_addr_fault+0x69b/0xcb0 arch/x86/mm/fault.c:1428 handle_page_fault arch/x86/mm/fault.c:1519 [inline] exc_page_fault+0x7a/0x110 arch/x86/mm/fault.c:1575 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570
-> #0 (&mm->mmap_lock){++++}-{3:3}: check_prev_add kernel/locking/lockdep.c:3097 [inline] check_prevs_add kernel/locking/lockdep.c:3216 [inline] validate_chain+0x1898/0x6ae0 kernel/locking/lockdep.c:3831 __lock_acquire+0x1292/0x1f60 kernel/locking/lockdep.c:5055 lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5668 __might_fault+0xb2/0x110 mm/memory.c:5647 _copy_to_user+0x26/0x130 lib/usercopy.c:29 copy_to_user include/linux/uaccess.h:169 [inline] f2fs_ioc_get_encryption_pwsalt fs/f2fs/file.c:2365 [inline] __f2fs_ioctl+0xaf72/0xb540 fs/f2fs/file.c:4169 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xfb/0x170 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
other info that might help us debug this:
Chain exists of: &mm->mmap_lock --> &nm_i->nat_tree_lock --> &sbi->sb_lock
Possible unsafe locking scenario:
CPU0 CPU1 ---- ---- lock(&sbi->sb_lock); lock(&nm_i->nat_tree_lock); lock(&sbi->sb_lock); lock(&mm->mmap_lock);
*** DEADLOCK ***
2 locks held by syz-executor.4/7644: #0: ffff888029ce0460 (sb_writers#30){.+.+}-{0:0}, at: mnt_want_write_file+0x5a/0x1f0 fs/namespace.c:552 #1: ffff88802babc088 (&sbi->sb_lock){++++}-{3:3}, at: f2fs_down_write fs/f2fs/f2fs.h:2213 [inline] #1: ffff88802babc088 (&sbi->sb_lock){++++}-{3:3}, at: f2fs_ioc_get_encryption_pwsalt fs/f2fs/file.c:2350 [inline] #1: ffff88802babc088 (&sbi->sb_lock){++++}-{3:3}, at: __f2fs_ioctl+0x3572/0xb540 fs/f2fs/file.c:4169
stack backtrace: CPU: 1 PID: 7644 Comm: syz-executor.4 Not tainted 6.2.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1b1/0x290 lib/dump_stack.c:106 check_noncircular+0x2cc/0x390 kernel/locking/lockdep.c:2177 check_prev_add kernel/locking/lockdep.c:3097 [inline] check_prevs_add kernel/locking/lockdep.c:3216 [inline] validate_chain+0x1898/0x6ae0 kernel/locking/lockdep.c:3831 __lock_acquire+0x1292/0x1f60 kernel/locking/lockdep.c:5055 lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5668 __might_fault+0xb2/0x110 mm/memory.c:5647 _copy_to_user+0x26/0x130 lib/usercopy.c:29 copy_to_user include/linux/uaccess.h:169 [inline] f2fs_ioc_get_encryption_pwsalt fs/f2fs/file.c:2365 [inline] __f2fs_ioctl+0xaf72/0xb540 fs/f2fs/file.c:4169 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xfb/0x170 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 RIP: 0033:0x7f84dbc8c0c9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f84dc990168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f84dbdac050 RCX: 00007f84dbc8c0c9 RDX: 0000000020000680 RSI: 0000000040106614 RDI: 0000000000000006 RBP: 00007f84dbce7ae9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fffc413f05f R14: 00007f84dc990300 R15: 0000000000022000 </TASK>
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