====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.4.180/5252 is trying to acquire lock: ffff888054d0cae0 (&sdp->sd_quota_mutex){+.+.}-{3:3}, at: do_qc+0xca/0x730 fs/gfs2/quota.c:682 but task is already holding lock: ffff88807114d688 (&ip->i_rw_mutex){++++}-{3:3}, at: sweep_bh_for_rgrps fs/gfs2/bmap.c:1512 [inline] ffff88807114d688 (&ip->i_rw_mutex){++++}-{3:3}, at: punch_hole+0x241b/0x35c0 fs/gfs2/bmap.c:1837 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&ip->i_rw_mutex){++++}-{3:3}: down_read+0x42/0x2d0 kernel/locking/rwsem.c:1520 __gfs2_iomap_get+0x155/0x13e0 fs/gfs2/bmap.c:856 gfs2_iomap_get+0xc1/0x120 fs/gfs2/bmap.c:1396 bh_get+0x241/0x730 fs/gfs2/quota.c:385 qdsb_get+0x21c/0x3c0 fs/gfs2/quota.c:522 gfs2_quota_hold+0x194/0x5d0 fs/gfs2/quota.c:608 gfs2_quota_lock+0xa0/0x7d0 fs/gfs2/quota.c:1076 gfs2_quota_lock_check fs/gfs2/quota.h:50 [inline] alloc_dinode+0x164/0x4f0 fs/gfs2/inode.c:393 gfs2_create_inode+0xc73/0x1400 fs/gfs2/inode.c:712 gfs2_atomic_open+0xce/0x210 fs/gfs2/inode.c:1293 atomic_open fs/namei.c:3345 [inline] lookup_open fs/namei.c:3453 [inline] open_last_lookups fs/namei.c:3550 [inline] path_openat+0xe20/0x2e70 fs/namei.c:3780 do_filp_open+0x1c1/0x3c0 fs/namei.c:3810 do_sys_openat2+0x142/0x490 fs/open.c:1318 do_sys_open fs/open.c:1334 [inline] __do_sys_openat fs/open.c:1350 [inline] __se_sys_openat fs/open.c:1345 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1345 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 (&sdp->sd_quota_mutex){+.+.}-{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 do_qc+0xca/0x730 fs/gfs2/quota.c:682 gfs2_quota_change+0x2f5/0x8e0 fs/gfs2/quota.c:1295 punch_hole+0x304c/0x35c0 fs/gfs2/bmap.c:1938 gfs2_iomap_end+0x4f2/0x6b0 fs/gfs2/bmap.c:1157 iomap_iter+0x21a/0x1040 fs/iomap/iter.c:79 iomap_file_buffered_write+0x74a/0x880 fs/iomap/buffered-io.c:846 gfs2_file_buffered_write+0x4fe/0x880 fs/gfs2/file.c:1057 gfs2_file_write_iter+0x42c/0xdf0 fs/gfs2/file.c:1158 __kernel_write_iter+0x26d/0x630 fs/read_write.c:517 dump_emit_page fs/coredump.c:950 [inline] dump_user_range+0x3ea/0x7f0 fs/coredump.c:977 elf_core_dump+0x2f77/0x3490 fs/binfmt_elf.c:2354 do_coredump+0x15ff/0x22b0 fs/coredump.c:824 get_signal+0x10aa/0x1350 kernel/signal.c:2857 arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:316 exc_page_fault+0x88/0x100 arch/x86/mm/fault.c:1490 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608 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.4.180/5252: #0: ffff888028a88460 (sb_writers#19){.+.+}-{0:0}, at: do_coredump+0x15de/0x22b0 fs/coredump.c:823 #1: ffff88807114d1f0 (&sb->s_type->i_mutex_key#27){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #1: ffff88807114d1f0 (&sb->s_type->i_mutex_key#27){+.+.}-{3:3}, at: gfs2_file_write_iter+0x308/0xdf0 fs/gfs2/file.c:1115 #2: ffff888028a88650 (sb_internal#4){.+.+}-{0:0}, at: gfs2_trans_begin+0x6b/0xe0 fs/gfs2/trans.c:118 #3: ffff888054d0d058 (&sdp->sd_log_flush_lock){.+.+}-{3:3}, at: __gfs2_trans_begin+0x50d/0x880 fs/gfs2/trans.c:87 #4: ffff88807114d688 (&ip->i_rw_mutex){++++}-{3:3}, at: sweep_bh_for_rgrps fs/gfs2/bmap.c:1512 [inline] #4: ffff88807114d688 (&ip->i_rw_mutex){++++}-{3:3}, at: punch_hole+0x241b/0x35c0 fs/gfs2/bmap.c:1837 stack backtrace: CPU: 0 PID: 5252 Comm: syz.4.180 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 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 do_qc+0xca/0x730 fs/gfs2/quota.c:682 gfs2_quota_change+0x2f5/0x8e0 fs/gfs2/quota.c:1295 punch_hole+0x304c/0x35c0 fs/gfs2/bmap.c:1938 gfs2_iomap_end+0x4f2/0x6b0 fs/gfs2/bmap.c:1157 iomap_iter+0x21a/0x1040 fs/iomap/iter.c:79 iomap_file_buffered_write+0x74a/0x880 fs/iomap/buffered-io.c:846 gfs2_file_buffered_write+0x4fe/0x880 fs/gfs2/file.c:1057 gfs2_file_write_iter+0x42c/0xdf0 fs/gfs2/file.c:1158 __kernel_write_iter+0x26d/0x630 fs/read_write.c:517 dump_emit_page fs/coredump.c:950 [inline] dump_user_range+0x3ea/0x7f0 fs/coredump.c:977 elf_core_dump+0x2f77/0x3490 fs/binfmt_elf.c:2354 do_coredump+0x15ff/0x22b0 fs/coredump.c:824 get_signal+0x10aa/0x1350 kernel/signal.c:2857 arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:316 exc_page_fault+0x88/0x100 arch/x86/mm/fault.c:1490 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0x7f86f0b8ebb1 Code: 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 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f RSP: 002b:fffffffffffffe70 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007f86f0dd6090 RCX: 00007f86f0b8eba9 RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000 RBP: 00007f86f0c11e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f86f0dd6128 R14: 00007f86f0dd6090 R15: 00007ffdf5d63bf8