====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.7.1250/13857 is trying to acquire lock: ffff88804f6c6b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: do_writepages+0x27a/0x600 mm/page-writeback.c:2598 but task is already holding lock: ffff88804ba06aa8 (&ei->xattr_sem){++++}-{4:4}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:164 [inline] ffff88804ba06aa8 (&ei->xattr_sem){++++}-{4:4}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:6389 [inline] ffff88804ba06aa8 (&ei->xattr_sem){++++}-{4:4}, at: __ext4_mark_inode_dirty+0x4ba/0x840 fs/ext4/inode.c:6470 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&ei->xattr_sem){++++}-{4:4}: down_write+0x92/0x200 kernel/locking/rwsem.c:1590 ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline] ext4_inline_data_truncate+0x1b3/0xc80 fs/ext4/inline.c:1856 ext4_truncate+0x9bd/0x11c0 fs/ext4/inode.c:4566 ext4_evict_inode+0x76d/0x1730 fs/ext4/inode.c:260 evict+0x3c2/0xad0 fs/inode.c:837 iput_final fs/inode.c:1951 [inline] iput.part.0+0x621/0x1190 fs/inode.c:2003 iput+0x35/0x40 fs/inode.c:1966 d_delete_notify include/linux/fsnotify.h:377 [inline] vfs_rmdir fs/namei.c:5249 [inline] vfs_rmdir+0x622/0x840 fs/namei.c:5209 do_rmdir+0x3be/0x560 fs/namei.c:5291 __do_sys_unlinkat fs/namei.c:5468 [inline] __se_sys_unlinkat fs/namei.c:5462 [inline] __x64_sys_unlinkat+0xef/0x130 fs/namei.c:5462 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (sb_internal){.+.+}-{0:0}: percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline] percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline] __sb_start_write include/linux/fs/super.h:19 [inline] sb_start_intwrite include/linux/fs/super.h:177 [inline] ext4_evict_inode+0xccd/0x1730 fs/ext4/inode.c:214 evict+0x3c2/0xad0 fs/inode.c:837 iput_final fs/inode.c:1951 [inline] iput.part.0+0x621/0x1190 fs/inode.c:2003 iput+0x35/0x40 fs/inode.c:1966 ext4_ext_migrate+0xc6f/0x1ee0 fs/ext4/migrate.c:588 __ext4_ioctl+0x1de3/0x4220 fs/ext4/ioctl.c:1688 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&sbi->s_writepages_rwsem){++++}-{0:0}: check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x1669/0x2890 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825 percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline] percpu_down_read include/linux/percpu-rwsem.h:77 [inline] ext4_writepages_down_read fs/ext4/ext4.h:1820 [inline] ext4_writepages+0x224/0x7d0 fs/ext4/inode.c:3025 do_writepages+0x27a/0x600 mm/page-writeback.c:2598 __writeback_single_inode+0x168/0x14a0 fs/fs-writeback.c:1737 writeback_single_inode+0x425/0x10f0 fs/fs-writeback.c:1858 write_inode_now+0x170/0x1e0 fs/fs-writeback.c:2924 iput_final fs/inode.c:1941 [inline] iput.part.0+0x815/0x1190 fs/inode.c:2003 iput+0x35/0x40 fs/inode.c:1966 ext4_xattr_block_set+0x67c/0x3640 fs/ext4/xattr.c:2203 ext4_xattr_move_to_block fs/ext4/xattr.c:2668 [inline] ext4_xattr_make_inode_space fs/ext4/xattr.c:2743 [inline] ext4_expand_extra_isize_ea+0x1442/0x1ab0 fs/ext4/xattr.c:2831 __ext4_expand_extra_isize+0x346/0x480 fs/ext4/inode.c:6349 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6392 [inline] __ext4_mark_inode_dirty+0x544/0x840 fs/ext4/inode.c:6470 ext4_evict_inode+0x713/0x1730 fs/ext4/inode.c:253 evict+0x3c2/0xad0 fs/inode.c:837 iput_final fs/inode.c:1951 [inline] iput.part.0+0x621/0x1190 fs/inode.c:2003 iput+0x35/0x40 fs/inode.c:1966 ext4_orphan_cleanup+0x731/0x11e0 fs/ext4/orphan.c:472 __ext4_fill_super fs/ext4/super.c:5658 [inline] ext4_fill_super+0x7ec1/0xb570 fs/ext4/super.c:5777 get_tree_bdev_flags+0x38c/0x620 fs/super.c:1691 vfs_get_tree+0x8e/0x330 fs/super.c:1751 fc_mount fs/namespace.c:1199 [inline] do_new_mount_fc fs/namespace.c:3636 [inline] do_new_mount fs/namespace.c:3712 [inline] path_mount+0x7bf/0x23a0 fs/namespace.c:4022 do_mount fs/namespace.c:4035 [inline] __do_sys_mount fs/namespace.c:4224 [inline] __se_sys_mount fs/namespace.c:4201 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:4201 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: &sbi->s_writepages_rwsem --> sb_internal --> &ei->xattr_sem Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ei->xattr_sem); lock(sb_internal); lock(&ei->xattr_sem); rlock(&sbi->s_writepages_rwsem); *** DEADLOCK *** 3 locks held by syz.7.1250/13857: #0: ffff888031ce80e0 (&type->s_umount_key#27/1){+.+.}-{4:4}, at: alloc_super+0x244/0xd00 fs/super.c:344 #1: ffff888031ce8610 (sb_internal){.+.+}-{0:0}, at: evict+0x3c2/0xad0 fs/inode.c:837 #2: ffff88804ba06aa8 (&ei->xattr_sem){++++}-{4:4}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:164 [inline] #2: ffff88804ba06aa8 (&ei->xattr_sem){++++}-{4:4}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:6389 [inline] #2: ffff88804ba06aa8 (&ei->xattr_sem){++++}-{4:4}, at: __ext4_mark_inode_dirty+0x4ba/0x840 fs/ext4/inode.c:6470 stack backtrace: CPU: 1 UID: 0 PID: 13857 Comm: syz.7.1250 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_circular_bug+0x275/0x340 kernel/locking/lockdep.c:2043 check_noncircular+0x146/0x160 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x1669/0x2890 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825 percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline] percpu_down_read include/linux/percpu-rwsem.h:77 [inline] ext4_writepages_down_read fs/ext4/ext4.h:1820 [inline] ext4_writepages+0x224/0x7d0 fs/ext4/inode.c:3025 do_writepages+0x27a/0x600 mm/page-writeback.c:2598 __writeback_single_inode+0x168/0x14a0 fs/fs-writeback.c:1737 writeback_single_inode+0x425/0x10f0 fs/fs-writeback.c:1858 write_inode_now+0x170/0x1e0 fs/fs-writeback.c:2924 iput_final fs/inode.c:1941 [inline] iput.part.0+0x815/0x1190 fs/inode.c:2003 iput+0x35/0x40 fs/inode.c:1966 ext4_xattr_block_set+0x67c/0x3640 fs/ext4/xattr.c:2203 ext4_xattr_move_to_block fs/ext4/xattr.c:2668 [inline] ext4_xattr_make_inode_space fs/ext4/xattr.c:2743 [inline] ext4_expand_extra_isize_ea+0x1442/0x1ab0 fs/ext4/xattr.c:2831 __ext4_expand_extra_isize+0x346/0x480 fs/ext4/inode.c:6349 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6392 [inline] __ext4_mark_inode_dirty+0x544/0x840 fs/ext4/inode.c:6470 ext4_evict_inode+0x713/0x1730 fs/ext4/inode.c:253 evict+0x3c2/0xad0 fs/inode.c:837 iput_final fs/inode.c:1951 [inline] iput.part.0+0x621/0x1190 fs/inode.c:2003 iput+0x35/0x40 fs/inode.c:1966 ext4_orphan_cleanup+0x731/0x11e0 fs/ext4/orphan.c:472 __ext4_fill_super fs/ext4/super.c:5658 [inline] ext4_fill_super+0x7ec1/0xb570 fs/ext4/super.c:5777 get_tree_bdev_flags+0x38c/0x620 fs/super.c:1691 vfs_get_tree+0x8e/0x330 fs/super.c:1751 fc_mount fs/namespace.c:1199 [inline] do_new_mount_fc fs/namespace.c:3636 [inline] do_new_mount fs/namespace.c:3712 [inline] path_mount+0x7bf/0x23a0 fs/namespace.c:4022 do_mount fs/namespace.c:4035 [inline] __do_sys_mount fs/namespace.c:4224 [inline] __se_sys_mount fs/namespace.c:4201 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:4201 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f395db90eea Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007f395e970e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f395e970ef0 RCX: 00007f395db90eea RDX: 0000200000000180 RSI: 00002000000001c0 RDI: 00007f395e970eb0 RBP: 0000200000000180 R08: 00007f395e970ef0 R09: 0000000000800700 R10: 0000000000800700 R11: 0000000000000246 R12: 00002000000001c0 R13: 00007f395e970eb0 R14: 000000000000046f R15: 000000000000002c ------------[ cut here ]------------ EA inode 11 i_nlink=2 WARNING: fs/ext4/xattr.c:1056 at ext4_xattr_inode_update_ref+0x4b7/0x5b0 fs/ext4/xattr.c:1056, CPU#0: syz.7.1250/13857 Modules linked in: CPU: 0 UID: 0 PID: 13857 Comm: syz.7.1250 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:ext4_xattr_inode_update_ref+0x4be/0x5b0 fs/ext4/xattr.c:1056 Code: 40 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 f1 00 00 00 48 8d 3d 29 10 fb 0d 48 8b 73 40 44 89 e2 <67> 48 0f b9 3a e9 06 ff ff ff e8 63 09 2b ff 48 8d 7b 40 48 b8 00 RSP: 0018:ffffc90003437178 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: ffff88804bad1f78 RCX: ffffc90004431000 RDX: 0000000000000002 RSI: 000000000000000b RDI: ffffffff908eda50 RBP: ffffc90003437240 R08: 0000000000000005 R09: 0000000000000001 R10: 0000000000000002 R11: 0000000000000001 R12: 0000000000000002 R13: ffffffffffffffff R14: 1ffff92000686e32 R15: ffff88804bad2168 FS: 00007f395e9716c0(0000) GS:ffff8881248f6000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4a34e64fb8 CR3: 000000002a5d5000 CR4: 0000000000350ef0 Call Trace: ext4_xattr_inode_dec_ref fs/ext4/xattr.c:1081 [inline] ext4_xattr_set_entry+0x158f/0x1f00 fs/ext4/xattr.c:1723 ext4_xattr_ibody_set+0x3d6/0x5d0 fs/ext4/xattr.c:2272 ext4_xattr_move_to_block fs/ext4/xattr.c:2675 [inline] ext4_xattr_make_inode_space fs/ext4/xattr.c:2743 [inline] ext4_expand_extra_isize_ea+0x148c/0x1ab0 fs/ext4/xattr.c:2831 __ext4_expand_extra_isize+0x346/0x480 fs/ext4/inode.c:6349 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6392 [inline] __ext4_mark_inode_dirty+0x544/0x840 fs/ext4/inode.c:6470 ext4_evict_inode+0x713/0x1730 fs/ext4/inode.c:253 evict+0x3c2/0xad0 fs/inode.c:837 iput_final fs/inode.c:1951 [inline] iput.part.0+0x621/0x1190 fs/inode.c:2003 iput+0x35/0x40 fs/inode.c:1966 ext4_orphan_cleanup+0x731/0x11e0 fs/ext4/orphan.c:472 __ext4_fill_super fs/ext4/super.c:5658 [inline] ext4_fill_super+0x7ec1/0xb570 fs/ext4/super.c:5777 get_tree_bdev_flags+0x38c/0x620 fs/super.c:1691 vfs_get_tree+0x8e/0x330 fs/super.c:1751 fc_mount fs/namespace.c:1199 [inline] do_new_mount_fc fs/namespace.c:3636 [inline] do_new_mount fs/namespace.c:3712 [inline] path_mount+0x7bf/0x23a0 fs/namespace.c:4022 do_mount fs/namespace.c:4035 [inline] __do_sys_mount fs/namespace.c:4224 [inline] __se_sys_mount fs/namespace.c:4201 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:4201 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f395db90eea Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007f395e970e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f395e970ef0 RCX: 00007f395db90eea RDX: 0000200000000180 RSI: 00002000000001c0 RDI: 00007f395e970eb0 RBP: 0000200000000180 R08: 00007f395e970ef0 R09: 0000000000800700 R10: 0000000000800700 R11: 0000000000000246 R12: 00002000000001c0 R13: 00007f395e970eb0 R14: 000000000000046f R15: 000000000000002c ---------------- Code disassembly (best guess): 0: 40 rex 1: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 8: fc ff df b: 48 89 fa mov %rdi,%rdx e: 48 c1 ea 03 shr $0x3,%rdx 12: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) 16: 0f 85 f1 00 00 00 jne 0x10d 1c: 48 8d 3d 29 10 fb 0d lea 0xdfb1029(%rip),%rdi # 0xdfb104c 23: 48 8b 73 40 mov 0x40(%rbx),%rsi 27: 44 89 e2 mov %r12d,%edx * 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction 2f: e9 06 ff ff ff jmp 0xffffff3a 34: e8 63 09 2b ff call 0xff2b099c 39: 48 8d 7b 40 lea 0x40(%rbx),%rdi 3d: 48 rex.W 3e: b8 .byte 0xb8