====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.4.2390/14114 is trying to acquire lock: ffff8880562f1090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27 but task is already holding lock: ffff88805bcb2558 (sb_pagefaults#2){.+.+}-{0:0}, at: do_page_mkwrite+0x16b/0x5c0 mm/memory.c:3011 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (sb_pagefaults#2){.+.+}-{0:0}: percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1891 [inline] sb_start_pagefault include/linux/fs.h:1995 [inline] filemap_page_mkwrite+0x167/0x630 mm/filemap.c:3545 do_page_mkwrite+0x16b/0x5c0 mm/memory.c:3011 do_shared_fault mm/memory.c:4696 [inline] do_fault mm/memory.c:4764 [inline] handle_pte_fault mm/memory.c:5031 [inline] __handle_mm_fault mm/memory.c:5173 [inline] handle_mm_fault+0x1b10/0x3e60 mm/memory.c:5294 faultin_page mm/gup.c:1026 [inline] __get_user_pages+0x3ff/0xeb0 mm/gup.c:1250 faultin_vma_page_range+0x1dc/0x270 mm/gup.c:1670 madvise_populate mm/madvise.c:928 [inline] madvise_vma_behavior mm/madvise.c:1037 [inline] madvise_walk_vmas mm/madvise.c:1259 [inline] do_madvise+0x122a/0x33d0 mm/madvise.c:1438 __do_sys_madvise mm/madvise.c:1451 [inline] __se_sys_madvise mm/madvise.c:1449 [inline] __x64_sys_madvise+0xa2/0xb0 mm/madvise.c:1449 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #1 (&mm->mmap_lock){++++}-{3:3}: __might_fault+0xc2/0x120 mm/memory.c:5852 reiserfs_ioctl+0x13b/0x330 fs/reiserfs/ioctl.c:96 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #0 (&sbi->lock){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x2cf8/0x7c50 kernel/locking/lockdep.c:5049 lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x120/0xaf0 kernel/locking/mutex.c:747 reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27 reiserfs_dirty_inode+0xf0/0x240 fs/reiserfs/super.c:704 __mark_inode_dirty+0x2eb/0xe90 fs/fs-writeback.c:2443 generic_update_time fs/inode.c:1946 [inline] inode_update_time fs/inode.c:1959 [inline] __file_update_time+0x21d/0x240 fs/inode.c:2147 file_update_time+0x2d3/0x340 fs/inode.c:2178 filemap_page_mkwrite+0x271/0x630 mm/filemap.c:3546 do_page_mkwrite+0x16b/0x5c0 mm/memory.c:3011 wp_page_shared+0x167/0x370 mm/memory.c:3360 handle_pte_fault mm/memory.c:5049 [inline] __handle_mm_fault mm/memory.c:5173 [inline] handle_mm_fault+0x1ca6/0x3e60 mm/memory.c:5294 do_user_addr_fault+0x51f/0xb10 arch/x86/mm/fault.c:1340 handle_page_fault arch/x86/mm/fault.c:1431 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1487 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608 other info that might help us debug this: Chain exists of: &sbi->lock --> &mm->mmap_lock --> sb_pagefaults#2 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(sb_pagefaults#2); lock(&mm->mmap_lock); lock(sb_pagefaults#2); lock(&sbi->lock); *** DEADLOCK *** 2 locks held by syz.4.2390/14114: #0: ffff88807743cc58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline] #0: ffff88807743cc58 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5322 [inline] #0: ffff88807743cc58 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x2e/0x2f0 mm/memory.c:5384 #1: ffff88805bcb2558 (sb_pagefaults#2){.+.+}-{0:0}, at: do_page_mkwrite+0x16b/0x5c0 mm/memory.c:3011 stack backtrace: CPU: 0 PID: 14114 Comm: syz.4.2390 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 check_noncircular+0x274/0x310 kernel/locking/lockdep.c:2170 check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x2cf8/0x7c50 kernel/locking/lockdep.c:5049 lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x120/0xaf0 kernel/locking/mutex.c:747 reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27 reiserfs_dirty_inode+0xf0/0x240 fs/reiserfs/super.c:704 __mark_inode_dirty+0x2eb/0xe90 fs/fs-writeback.c:2443 generic_update_time fs/inode.c:1946 [inline] inode_update_time fs/inode.c:1959 [inline] __file_update_time+0x21d/0x240 fs/inode.c:2147 file_update_time+0x2d3/0x340 fs/inode.c:2178 filemap_page_mkwrite+0x271/0x630 mm/filemap.c:3546 do_page_mkwrite+0x16b/0x5c0 mm/memory.c:3011 wp_page_shared+0x167/0x370 mm/memory.c:3360 handle_pte_fault mm/memory.c:5049 [inline] __handle_mm_fault mm/memory.c:5173 [inline] handle_mm_fault+0x1ca6/0x3e60 mm/memory.c:5294 do_user_addr_fault+0x51f/0xb10 arch/x86/mm/fault.c:1340 handle_page_fault arch/x86/mm/fault.c:1431 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1487 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0x7ff029f57398 Code: fc 89 37 c3 c5 fa 6f 06 c5 fa 6f 4c 16 f0 c5 fa 7f 07 c5 fa 7f 4c 17 f0 c3 66 0f 1f 84 00 00 00 00 00 48 8b 4c 16 f8 48 8b 36 <48> 89 37 48 89 4c 17 f8 c3 c5 fe 6f 54 16 e0 c5 fe 6f 5c 16 c0 c5 RSP: 002b:00007ffe3c374148 EFLAGS: 00010202 RAX: 00002000000001c0 RBX: 0000000000000004 RCX: 0072736d2f232f75 RDX: 000000000000000f RSI: 7570632f7665642f RDI: 00002000000001c0 RBP: 00007ff02a1e7da0 R08: 0000001b2e920000 R09: 0000000000000001 R10: 0000000000000001 R11: 0000000000000009 R12: 00007ff02a1e5fac R13: 00007ff02a1e5fa0 R14: fffffffffffffffe R15: 00007ffe3c374260