====================================================== WARNING: possible circular locking dependency detected 5.15.172-syzkaller #0 Not tainted ------------------------------------------------------ syz.2.2045/13061 is trying to acquire lock: ffff888021e24ae0 (&sdp->sd_quota_mutex){+.+.}-{3:3}, at: do_qc+0xc8/0x720 fs/gfs2/quota.c:678 but task is already holding lock: ffff8880611d2108 (&ip->i_rw_mutex){++++}-{3:3}, at: __gfs2_iomap_alloc+0x2b7/0x2090 fs/gfs2/bmap.c:681 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&ip->i_rw_mutex){++++}-{3:3}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 down_read+0x45/0x2e0 kernel/locking/rwsem.c:1498 __gfs2_iomap_get+0x178/0x1480 fs/gfs2/bmap.c:858 gfs2_iomap_get fs/gfs2/bmap.c:1398 [inline] gfs2_block_map+0x292/0x830 fs/gfs2/bmap.c:1213 bh_get+0x26d/0x6a0 fs/gfs2/quota.c:385 qdsb_get+0x209/0x3b0 fs/gfs2/quota.c:518 gfs2_quota_hold+0x19d/0x5c0 fs/gfs2/quota.c:604 gfs2_quota_lock+0x9f/0x450 fs/gfs2/quota.c:1076 gfs2_quota_lock_check fs/gfs2/quota.h:50 [inline] gfs2_page_mkwrite+0xda6/0x1590 fs/gfs2/file.c:489 do_page_mkwrite+0x1a9/0x440 mm/memory.c:2909 do_shared_fault mm/memory.c:4315 [inline] do_fault mm/memory.c:4383 [inline] handle_pte_fault mm/memory.c:4637 [inline] __handle_mm_fault mm/memory.c:4772 [inline] handle_mm_fault+0x2803/0x5960 mm/memory.c:4870 do_user_addr_fault arch/x86/mm/fault.c:1357 [inline] handle_page_fault arch/x86/mm/fault.c:1445 [inline] exc_page_fault+0x271/0x700 arch/x86/mm/fault.c:1501 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606 copy_user_enhanced_fast_string+0xe/0x40 arch/x86/lib/copy_user_64.S:205 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:58 [inline] _copy_to_user+0xef/0x130 lib/usercopy.c:40 copy_to_user include/linux/uaccess.h:200 [inline] rng_dev_read+0x397/0x6a0 drivers/char/hw_random/core.c:262 do_iter_read+0x4c6/0x760 fs/read_write.c:792 vfs_readv fs/read_write.c:910 [inline] do_preadv+0x211/0x350 fs/read_write.c:1002 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #0 (&sdp->sd_quota_mutex){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __mutex_lock_common+0x1da/0x25a0 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 do_qc+0xc8/0x720 fs/gfs2/quota.c:678 gfs2_quota_change+0x2db/0x8c0 fs/gfs2/quota.c:1295 gfs2_alloc_blocks+0x1f0a/0x2970 fs/gfs2/rgrp.c:2504 __gfs2_iomap_alloc+0x4f0/0x2090 fs/gfs2/bmap.c:707 gfs2_iomap_alloc+0x155/0x1f0 fs/gfs2/bmap.c:1411 gfs2_allocate_page_backing+0x134/0x250 fs/gfs2/file.c:401 gfs2_page_mkwrite+0x1245/0x1590 fs/gfs2/file.c:531 do_page_mkwrite+0x1a9/0x440 mm/memory.c:2909 do_shared_fault mm/memory.c:4315 [inline] do_fault mm/memory.c:4383 [inline] handle_pte_fault mm/memory.c:4637 [inline] __handle_mm_fault mm/memory.c:4772 [inline] handle_mm_fault+0x2803/0x5960 mm/memory.c:4870 do_user_addr_fault arch/x86/mm/fault.c:1357 [inline] handle_page_fault arch/x86/mm/fault.c:1445 [inline] exc_page_fault+0x271/0x700 arch/x86/mm/fault.c:1501 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606 copy_user_enhanced_fast_string+0xe/0x40 arch/x86/lib/copy_user_64.S:205 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:58 [inline] _copy_to_user+0xef/0x130 lib/usercopy.c:40 copy_to_user include/linux/uaccess.h:200 [inline] rng_dev_read+0x397/0x6a0 drivers/char/hw_random/core.c:262 do_iter_read+0x4c6/0x760 fs/read_write.c:792 vfs_readv fs/read_write.c:910 [inline] do_preadv+0x211/0x350 fs/read_write.c:1002 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ip->i_rw_mutex); lock(&sdp->sd_quota_mutex); lock(&ip->i_rw_mutex); lock(&sdp->sd_quota_mutex); *** DEADLOCK *** 5 locks held by syz.2.2045/13061: #0: ffff88802c79ea28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock+0x1c/0x50 include/linux/mmap_lock.h:117 #1: ffff888060d1a558 (sb_pagefaults#3){.+.+}-{0:0}, at: do_page_mkwrite+0x1a9/0x440 mm/memory.c:2909 #2: ffff888060d1a650 (sb_internal#6){.+.+}-{0:0}, at: gfs2_trans_begin+0x6d/0xe0 fs/gfs2/trans.c:118 #3: ffff888021e250a8 (&sdp->sd_log_flush_lock){++++}-{3:3}, at: __gfs2_trans_begin+0x55a/0x940 fs/gfs2/trans.c:87 #4: ffff8880611d2108 (&ip->i_rw_mutex){++++}-{3:3}, at: __gfs2_iomap_alloc+0x2b7/0x2090 fs/gfs2/bmap.c:681 stack backtrace: CPU: 0 PID: 13061 Comm: syz.2.2045 Not tainted 5.15.172-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 check_noncircular+0x2f8/0x3b0 kernel/locking/lockdep.c:2133 check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __mutex_lock_common+0x1da/0x25a0 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 do_qc+0xc8/0x720 fs/gfs2/quota.c:678 gfs2_quota_change+0x2db/0x8c0 fs/gfs2/quota.c:1295 gfs2_alloc_blocks+0x1f0a/0x2970 fs/gfs2/rgrp.c:2504 __gfs2_iomap_alloc+0x4f0/0x2090 fs/gfs2/bmap.c:707 gfs2_iomap_alloc+0x155/0x1f0 fs/gfs2/bmap.c:1411 gfs2_allocate_page_backing+0x134/0x250 fs/gfs2/file.c:401 gfs2_page_mkwrite+0x1245/0x1590 fs/gfs2/file.c:531 do_page_mkwrite+0x1a9/0x440 mm/memory.c:2909 do_shared_fault mm/memory.c:4315 [inline] do_fault mm/memory.c:4383 [inline] handle_pte_fault mm/memory.c:4637 [inline] __handle_mm_fault mm/memory.c:4772 [inline] handle_mm_fault+0x2803/0x5960 mm/memory.c:4870 do_user_addr_fault arch/x86/mm/fault.c:1357 [inline] handle_page_fault arch/x86/mm/fault.c:1445 [inline] exc_page_fault+0x271/0x700 arch/x86/mm/fault.c:1501 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606 RIP: 0010:copy_user_enhanced_fast_string+0xe/0x40 arch/x86/lib/copy_user_64.S:206 Code: 89 d1 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 31 c0 0f 01 ca c3 0f 1f 80 00 00 00 00 0f 01 cb 83 fa 40 0f 82 70 ff ff ff 89 d1 a4 31 c0 0f 01 ca c3 66 2e 0f 1f 84 00 00 00 00 00 89 d1 83 f8 RSP: 0018:ffffc900042d7b48 EFLAGS: 00050246 RAX: ffffffff84096f01 RBX: 0000000020021440 RCX: 0000000000000040 RDX: 0000000000000040 RSI: ffffc900042d7be0 RDI: 0000000020021400 RBP: ffffc900042d7c90 R08: dffffc0000000000 R09: fffff5200085af84 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000040 R13: 00007ffffffff000 R14: ffffc900042d7be0 R15: 0000000020021400 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:58 [inline] _copy_to_user+0xef/0x130 lib/usercopy.c:40 copy_to_user include/linux/uaccess.h:200 [inline] rng_dev_read+0x397/0x6a0 drivers/char/hw_random/core.c:262 do_iter_read+0x4c6/0x760 fs/read_write.c:792 vfs_readv fs/read_write.c:910 [inline] do_preadv+0x211/0x350 fs/read_write.c:1002 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f8110ee1719 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f810f359038 EFLAGS: 00000246 ORIG_RAX: 0000000000000127 RAX: ffffffffffffffda RBX: 00007f8111098f80 RCX: 00007f8110ee1719 RDX: 0000000000000001 RSI: 0000000020000580 RDI: 0000000000000006 RBP: 00007f8110f5475e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f8111098f80 R15: 00007ffcaefe09c8 ---------------- Code disassembly (best guess): 0: 89 d1 mov %edx,%ecx 2: c1 e9 03 shr $0x3,%ecx 5: 83 e2 07 and $0x7,%edx 8: f3 48 a5 rep movsq %ds:(%rsi),%es:(%rdi) b: 89 d1 mov %edx,%ecx d: f3 a4 rep movsb %ds:(%rsi),%es:(%rdi) f: 31 c0 xor %eax,%eax 11: 0f 01 ca clac 14: c3 ret 15: 0f 1f 80 00 00 00 00 nopl 0x0(%rax) 1c: 0f 01 cb stac 1f: 83 fa 40 cmp $0x40,%edx 22: 0f 82 70 ff ff ff jb 0xffffff98 28: 89 d1 mov %edx,%ecx * 2a: f3 a4 rep movsb %ds:(%rsi),%es:(%rdi) <-- trapping instruction 2c: 31 c0 xor %eax,%eax 2e: 0f 01 ca clac 31: c3 ret 32: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1) 39: 00 00 00 3c: 89 d1 mov %edx,%ecx 3e: 83 .byte 0x83 3f: f8 clc