====================================================== WARNING: possible circular locking dependency detected 6.15.0-rc4-syzkaller-00011-gf15d97df5afa #0 Not tainted ------------------------------------------------------ syz.0.0/5315 is trying to acquire lock: ffff888042f96a20 (&oi->ip_alloc_sem){++++}-{4:4}, at: ocfs2_page_mkwrite+0x2ff/0xc40 fs/ocfs2/mmap.c:142 but task is already holding lock: ffff88804225e518 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x14a/0x310 mm/memory.c:3287 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (sb_pagefaults){.+.+}-{0:0}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5866 percpu_down_read include/linux/percpu-rwsem.h:52 [inline] __sb_start_write include/linux/fs.h:1783 [inline] sb_start_pagefault include/linux/fs.h:1948 [inline] ocfs2_page_mkwrite+0x1da/0xc40 fs/ocfs2/mmap.c:122 do_page_mkwrite+0x14a/0x310 mm/memory.c:3287 wp_page_shared mm/memory.c:3688 [inline] do_wp_page+0x2626/0x5760 mm/memory.c:3907 handle_pte_fault mm/memory.c:6013 [inline] __handle_mm_fault+0x1028/0x5380 mm/memory.c:6140 handle_mm_fault+0x3f6/0x8c0 mm/memory.c:6309 do_user_addr_fault+0x764/0x1390 arch/x86/mm/fault.c:1388 handle_page_fault arch/x86/mm/fault.c:1480 [inline] exc_page_fault+0x68/0x110 arch/x86/mm/fault.c:1538 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 -> #1 (&mm->mmap_lock){++++}-{4:4}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5866 __might_fault+0xcc/0x130 mm/memory.c:7151 _inline_copy_to_user include/linux/uaccess.h:192 [inline] _copy_to_user+0x2c/0xb0 lib/usercopy.c:26 copy_to_user include/linux/uaccess.h:225 [inline] fiemap_fill_next_extent+0x1c0/0x390 fs/ioctl.c:145 ocfs2_fiemap_inline fs/ocfs2/extent_map.c:735 [inline] ocfs2_fiemap+0x9dc/0xc90 fs/ocfs2/extent_map.c:772 ioctl_fiemap fs/ioctl.c:220 [inline] do_vfs_ioctl+0x1638/0x1eb0 fs/ioctl.c:840 __do_sys_ioctl fs/ioctl.c:904 [inline] __se_sys_ioctl+0x82/0x170 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&oi->ip_alloc_sem){++++}-{4:4}: check_prev_add kernel/locking/lockdep.c:3166 [inline] check_prevs_add kernel/locking/lockdep.c:3285 [inline] validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3909 __lock_acquire+0xaac/0xd20 kernel/locking/lockdep.c:5235 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5866 down_write+0x96/0x1f0 kernel/locking/rwsem.c:1577 ocfs2_page_mkwrite+0x2ff/0xc40 fs/ocfs2/mmap.c:142 do_page_mkwrite+0x14a/0x310 mm/memory.c:3287 wp_page_shared mm/memory.c:3688 [inline] do_wp_page+0x2626/0x5760 mm/memory.c:3907 handle_pte_fault mm/memory.c:6013 [inline] __handle_mm_fault+0x1028/0x5380 mm/memory.c:6140 handle_mm_fault+0x3f6/0x8c0 mm/memory.c:6309 do_user_addr_fault+0x764/0x1390 arch/x86/mm/fault.c:1388 handle_page_fault arch/x86/mm/fault.c:1480 [inline] exc_page_fault+0x68/0x110 arch/x86/mm/fault.c:1538 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 other info that might help us debug this: Chain exists of: &oi->ip_alloc_sem --> &mm->mmap_lock --> sb_pagefaults Possible unsafe locking scenario: CPU0 CPU1 ---- ---- rlock(sb_pagefaults); lock(&mm->mmap_lock); lock(sb_pagefaults); lock(&oi->ip_alloc_sem); *** DEADLOCK *** 2 locks held by syz.0.0/5315: #0: ffff8880115d33e0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_trylock include/linux/mmap_lock.h:203 [inline] #0: ffff8880115d33e0 (&mm->mmap_lock){++++}-{4:4}, at: get_mmap_lock_carefully mm/memory.c:6346 [inline] #0: ffff8880115d33e0 (&mm->mmap_lock){++++}-{4:4}, at: lock_mm_and_find_vma+0x32/0x300 mm/memory.c:6406 #1: ffff88804225e518 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x14a/0x310 mm/memory.c:3287 stack backtrace: CPU: 0 UID: 0 PID: 5315 Comm: syz.0.0 Not tainted 6.15.0-rc4-syzkaller-00011-gf15d97df5afa #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2079 check_noncircular+0x134/0x160 kernel/locking/lockdep.c:2211 check_prev_add kernel/locking/lockdep.c:3166 [inline] check_prevs_add kernel/locking/lockdep.c:3285 [inline] validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3909 __lock_acquire+0xaac/0xd20 kernel/locking/lockdep.c:5235 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5866 down_write+0x96/0x1f0 kernel/locking/rwsem.c:1577 ocfs2_page_mkwrite+0x2ff/0xc40 fs/ocfs2/mmap.c:142 do_page_mkwrite+0x14a/0x310 mm/memory.c:3287 wp_page_shared mm/memory.c:3688 [inline] do_wp_page+0x2626/0x5760 mm/memory.c:3907 handle_pte_fault mm/memory.c:6013 [inline] __handle_mm_fault+0x1028/0x5380 mm/memory.c:6140 handle_mm_fault+0x3f6/0x8c0 mm/memory.c:6309 do_user_addr_fault+0x764/0x1390 arch/x86/mm/fault.c:1388 handle_page_fault arch/x86/mm/fault.c:1480 [inline] exc_page_fault+0x68/0x110 arch/x86/mm/fault.c:1538 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7f3974b57e48 Code: 66 89 74 17 02 88 0f c3 c5 fa 6f 06 c5 fa 6f 4c 16 f0 c5 fa 7f 07 c5 fa 7f 4c 17 f0 c3 0f 1f 44 00 00 48 8b 4c 16 f8 48 8b 36 <48> 89 37 48 89 4c 17 f8 c3 62 e1 fe 28 6f 54 16 ff 62 e1 fe 28 6f RSP: 002b:00007ffca0866668 EFLAGS: 00010206 RAX: 00002000000000c0 RBX: 0000000000000004 RCX: 006e75742d727472 RDX: 000000000000000e RSI: 7472712f7665642f RDI: 00002000000000c0 RBP: 00007f3974db7ba0 R08: 00007f39749ff02c R09: 0000000000000001 R10: 0000000000000001 R11: 0000000000000009 R12: 00007f3974db5fac R13: 00007f3974db5fa0 R14: fffffffffffffffe R15: 00007ffca0866780