====================================================== WARNING: possible circular locking dependency detected 6.9.0-rc3-syzkaller-gb5d2afe8745b #0 Not tainted ------------------------------------------------------ syz-executor.2/7125 is trying to acquire lock: ffff0000d01b3990 (&mm->mmap_lock){++++}-{3:3}, at: __might_fault+0x9c/0x124 mm/memory.c:6219 but task is already holding lock: ffff0000d7ba0068 (&f->sem){+.+.}-{3:3}, at: jffs2_readdir+0x230/0x42c fs/jffs2/dir.c:135 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&f->sem){+.+.}-{3:3}: __mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:608 __mutex_lock kernel/locking/mutex.c:752 [inline] mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:804 jffs2_read_folio+0x6c/0xd0 fs/jffs2/file.c:125 filemap_read_folio+0x14c/0x39c mm/filemap.c:2331 filemap_fault+0xab8/0x1004 mm/filemap.c:3381 __do_fault+0x11c/0x374 mm/memory.c:4531 do_read_fault mm/memory.c:4894 [inline] do_fault mm/memory.c:5024 [inline] do_pte_missing mm/memory.c:3880 [inline] handle_pte_fault mm/memory.c:5300 [inline] __handle_mm_fault+0x36d0/0x5920 mm/memory.c:5441 handle_mm_fault+0x1e8/0x63c mm/memory.c:5606 __do_page_fault arch/arm64/mm/fault.c:505 [inline] do_page_fault+0x550/0xaec arch/arm64/mm/fault.c:620 do_translation_fault+0xc4/0x114 arch/arm64/mm/fault.c:704 do_mem_abort+0x74/0x200 arch/arm64/mm/fault.c:840 el1_abort+0x3c/0x5c arch/arm64/kernel/entry-common.c:432 el1h_64_sync_handler+0x60/0xac arch/arm64/kernel/entry-common.c:492 el1h_64_sync+0x64/0x68 arch/arm64/kernel/entry.S:593 __uaccess_mask_ptr arch/arm64/include/asm/uaccess.h:169 [inline] netlink_getsockopt+0x168/0x83c net/netlink/af_netlink.c:1740 do_sock_getsockopt+0x274/0x660 net/socket.c:2373 __sys_getsockopt+0x120/0x19c net/socket.c:2402 __do_sys_getsockopt net/socket.c:2412 [inline] __se_sys_getsockopt net/socket.c:2409 [inline] __arm64_sys_getsockopt+0xb8/0xd4 net/socket.c:2409 __invoke_syscall arch/arm64/kernel/syscall.c:34 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:48 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:133 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:152 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:712 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598 -> #1 (mapping.invalidate_lock#3){.+.+}-{3:3}: down_read+0x58/0x2fc kernel/locking/rwsem.c:1526 filemap_invalidate_lock_shared include/linux/fs.h:850 [inline] filemap_fault+0x6b4/0x1004 mm/filemap.c:3296 __do_fault+0x11c/0x374 mm/memory.c:4531 do_read_fault mm/memory.c:4894 [inline] do_fault mm/memory.c:5024 [inline] do_pte_missing mm/memory.c:3880 [inline] handle_pte_fault mm/memory.c:5300 [inline] __handle_mm_fault+0x36d0/0x5920 mm/memory.c:5441 handle_mm_fault+0x1e8/0x63c mm/memory.c:5606 __do_page_fault arch/arm64/mm/fault.c:505 [inline] do_page_fault+0x550/0xaec arch/arm64/mm/fault.c:620 do_translation_fault+0xc4/0x114 arch/arm64/mm/fault.c:704 do_mem_abort+0x74/0x200 arch/arm64/mm/fault.c:840 el1_abort+0x3c/0x5c arch/arm64/kernel/entry-common.c:432 el1h_64_sync_handler+0x60/0xac arch/arm64/kernel/entry-common.c:492 el1h_64_sync+0x64/0x68 arch/arm64/kernel/entry.S:593 __uaccess_mask_ptr arch/arm64/include/asm/uaccess.h:169 [inline] netlink_getsockopt+0x168/0x83c net/netlink/af_netlink.c:1740 do_sock_getsockopt+0x274/0x660 net/socket.c:2373 __sys_getsockopt+0x120/0x19c net/socket.c:2402 __do_sys_getsockopt net/socket.c:2412 [inline] __se_sys_getsockopt net/socket.c:2409 [inline] __arm64_sys_getsockopt+0xb8/0xd4 net/socket.c:2409 __invoke_syscall arch/arm64/kernel/syscall.c:34 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:48 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:133 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:152 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:712 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598 -> #0 (&mm->mmap_lock){++++}-{3:3}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x3384/0x763c kernel/locking/lockdep.c:5137 lock_acquire+0x248/0x73c kernel/locking/lockdep.c:5754 __might_fault+0xc4/0x124 mm/memory.c:6220 filldir64+0x2d4/0x948 fs/readdir.c:375 dir_emit include/linux/fs.h:3570 [inline] jffs2_readdir+0x314/0x42c fs/jffs2/dir.c:152 iterate_dir+0x3f8/0x580 fs/readdir.c:110 __do_sys_getdents64 fs/readdir.c:409 [inline] __se_sys_getdents64 fs/readdir.c:394 [inline] __arm64_sys_getdents64+0x1c4/0x4a0 fs/readdir.c:394 __invoke_syscall arch/arm64/kernel/syscall.c:34 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:48 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:133 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:152 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:712 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598 other info that might help us debug this: Chain exists of: &mm->mmap_lock --> mapping.invalidate_lock#3 --> &f->sem Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&f->sem); lock(mapping.invalidate_lock#3); lock(&f->sem); rlock(&mm->mmap_lock); *** DEADLOCK *** 3 locks held by syz-executor.2/7125: #0: ffff0000d96619c8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x218/0x2a4 fs/file.c:1191 #1: ffff0000d7ba0218 (&type->i_mutex_dir_key#10){++++}-{3:3}, at: iterate_dir+0x340/0x580 fs/readdir.c:103 #2: ffff0000d7ba0068 (&f->sem){+.+.}-{3:3}, at: jffs2_readdir+0x230/0x42c fs/jffs2/dir.c:135 stack backtrace: CPU: 0 PID: 7125 Comm: syz-executor.2 Not tainted 6.9.0-rc3-syzkaller-gb5d2afe8745b #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call trace: dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:317 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:324 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xe4/0x150 lib/dump_stack.c:114 dump_stack+0x1c/0x28 lib/dump_stack.c:123 print_circular_bug+0x150/0x1b8 kernel/locking/lockdep.c:2060 check_noncircular+0x310/0x404 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x3384/0x763c kernel/locking/lockdep.c:5137 lock_acquire+0x248/0x73c kernel/locking/lockdep.c:5754 __might_fault+0xc4/0x124 mm/memory.c:6220 filldir64+0x2d4/0x948 fs/readdir.c:375 dir_emit include/linux/fs.h:3570 [inline] jffs2_readdir+0x314/0x42c fs/jffs2/dir.c:152 iterate_dir+0x3f8/0x580 fs/readdir.c:110 __do_sys_getdents64 fs/readdir.c:409 [inline] __se_sys_getdents64 fs/readdir.c:394 [inline] __arm64_sys_getdents64+0x1c4/0x4a0 fs/readdir.c:394 __invoke_syscall arch/arm64/kernel/syscall.c:34 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:48 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:133 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:152 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:712 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598 EXT4-fs (loop2): unmounting filesystem 00000000-0000-0000-0000-000000000000. EXT4-fs (loop2): unmounting filesystem 00000000-0000-0000-0000-000000000000. EXT4-fs (loop2): unmounting filesystem 00000000-0000-0000-0000-000000000000. EXT4-fs (loop2): unmounting filesystem 00000000-0000-0000-0000-000000000000. BTRFS info (device loop2): last unmount of filesystem 395ef67a-297e-477c-816d-cd80a5b93e5d XFS (loop2): Unmounting Filesystem c496e05e-540d-4c72-b591-04d79d8b4eeb