====================================================== WARNING: possible circular locking dependency detected 6.6.97-syzkaller #0 Not tainted ------------------------------------------------------ syz.8.239/7227 is trying to acquire lock: ffff88807913cae8 (&sdp->sd_quota_mutex){+.+.}-{3:3}, at: do_qc+0xaf/0x670 fs/gfs2/quota.c:689 but task is already holding lock: ffff88805bb585e8 (&ip->i_rw_mutex){++++}-{3:3}, at: gfs2_unstuff_dinode+0x9f/0x17d0 fs/gfs2/bmap.c:163 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+0x46/0x2e0 kernel/locking/rwsem.c:1520 __gfs2_iomap_get+0x159/0x13f0 fs/gfs2/bmap.c:856 gfs2_iomap_get+0xc5/0x120 fs/gfs2/bmap.c:1410 bh_get+0x225/0x710 fs/gfs2/quota.c:401 qdsb_get+0x210/0x330 fs/gfs2/quota.c:535 gfs2_quota_hold+0x198/0x5e0 fs/gfs2/quota.c:615 gfs2_quota_lock+0xba/0x7b0 fs/gfs2/quota.c:1070 gfs2_quota_lock_check fs/gfs2/quota.h:50 [inline] alloc_dinode+0x169/0x580 fs/gfs2/inode.c:409 gfs2_create_inode+0xcb4/0x1430 fs/gfs2/inode.c:739 gfs2_atomic_open+0xd2/0x220 fs/gfs2/inode.c:1315 atomic_open fs/namei.c:3351 [inline] lookup_open fs/namei.c:3459 [inline] open_last_lookups fs/namei.c:3556 [inline] path_openat+0xf27/0x3190 fs/namei.c:3786 do_filp_open+0x1c5/0x3d0 fs/namei.c:3816 file_open_name fs/open.c:1364 [inline] filp_open+0x177/0x1d0 fs/open.c:1384 do_coredump+0x1c22/0x2480 fs/coredump.c:774 get_signal+0x1133/0x1400 kernel/signal.c:2888 arch_do_signal_or_restart+0x96/0x780 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 irqentry_exit_to_user_mode+0x9/0x40 kernel/entry/common.c:315 exc_page_fault+0x8f/0x110 arch/x86/mm/fault.c:1524 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608 -> #0 (&sdp->sd_quota_mutex){+.+.}-{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+0x2ddb/0x7c80 kernel/locking/lockdep.c:5137 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x129/0xcc0 kernel/locking/mutex.c:747 do_qc+0xaf/0x670 fs/gfs2/quota.c:689 gfs2_quota_change+0x2b9/0x800 fs/gfs2/quota.c:1289 gfs2_alloc_blocks+0x18a8/0x2060 fs/gfs2/rgrp.c:2496 __gfs2_unstuff_inode fs/gfs2/bmap.c:109 [inline] gfs2_unstuff_dinode+0x212/0x17d0 fs/gfs2/bmap.c:168 gfs2_iomap_begin_write fs/gfs2/bmap.c:1050 [inline] gfs2_iomap_begin+0x9ea/0x1260 fs/gfs2/bmap.c:1126 iomap_iter+0x6b1/0xec0 fs/iomap/iter.c:91 iomap_file_buffered_write+0x1b5/0xd10 fs/iomap/buffered-io.c:974 gfs2_file_buffered_write+0x4bd/0x820 fs/gfs2/file.c:1060 gfs2_file_write_iter+0x427/0xe10 fs/gfs2/file.c:1158 __kernel_write_iter+0x274/0x670 fs/read_write.c:517 __kernel_write+0xf0/0x140 fs/read_write.c:537 __dump_emit+0x206/0x310 fs/coredump.c:882 elf_core_dump+0x2b53/0x36e0 fs/binfmt_elf.c:2163 do_coredump+0x1755/0x2480 fs/coredump.c:833 get_signal+0x1133/0x1400 kernel/signal.c:2888 arch_do_signal_or_restart+0x96/0x780 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 irqentry_exit_to_user_mode+0x9/0x40 kernel/entry/common.c:315 exc_page_fault+0x8f/0x110 arch/x86/mm/fault.c:1524 asm_exc_page_fault+0x26/0x30 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.8.239/7227: #0: ffff888027572418 (sb_writers#22){.+.+}-{0:0}, at: do_coredump+0x1734/0x2480 fs/coredump.c:832 #1: ffff88805bb58160 (&sb->s_type->i_mutex_key#27){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline] #1: ffff88805bb58160 (&sb->s_type->i_mutex_key#27){+.+.}-{3:3}, at: gfs2_file_write_iter+0x304/0xe10 fs/gfs2/file.c:1115 #2: ffff888027572608 (sb_internal#5){.+.+}-{0:0}, at: gfs2_trans_begin+0x6f/0xe0 fs/gfs2/trans.c:118 #3: ffff88807913d060 (&sdp->sd_log_flush_lock){++++}-{3:3}, at: __gfs2_trans_begin+0x511/0x880 fs/gfs2/trans.c:87 #4: ffff88805bb585e8 (&ip->i_rw_mutex){++++}-{3:3}, at: gfs2_unstuff_dinode+0x9f/0x17d0 fs/gfs2/bmap.c:163 stack backtrace: CPU: 0 PID: 7227 Comm: syz.8.239 Not tainted 6.6.97-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 check_noncircular+0x2bd/0x3c0 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+0x2ddb/0x7c80 kernel/locking/lockdep.c:5137 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x129/0xcc0 kernel/locking/mutex.c:747 do_qc+0xaf/0x670 fs/gfs2/quota.c:689 gfs2_quota_change+0x2b9/0x800 fs/gfs2/quota.c:1289 gfs2_alloc_blocks+0x18a8/0x2060 fs/gfs2/rgrp.c:2496 __gfs2_unstuff_inode fs/gfs2/bmap.c:109 [inline] gfs2_unstuff_dinode+0x212/0x17d0 fs/gfs2/bmap.c:168 gfs2_iomap_begin_write fs/gfs2/bmap.c:1050 [inline] gfs2_iomap_begin+0x9ea/0x1260 fs/gfs2/bmap.c:1126 iomap_iter+0x6b1/0xec0 fs/iomap/iter.c:91 iomap_file_buffered_write+0x1b5/0xd10 fs/iomap/buffered-io.c:974 gfs2_file_buffered_write+0x4bd/0x820 fs/gfs2/file.c:1060 gfs2_file_write_iter+0x427/0xe10 fs/gfs2/file.c:1158 __kernel_write_iter+0x274/0x670 fs/read_write.c:517 __kernel_write+0xf0/0x140 fs/read_write.c:537 __dump_emit+0x206/0x310 fs/coredump.c:882 elf_core_dump+0x2b53/0x36e0 fs/binfmt_elf.c:2163 do_coredump+0x1755/0x2480 fs/coredump.c:833 get_signal+0x1133/0x1400 kernel/signal.c:2888 arch_do_signal_or_restart+0x96/0x780 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 irqentry_exit_to_user_mode+0x9/0x40 kernel/entry/common.c:315 exc_page_fault+0x8f/0x110 arch/x86/mm/fault.c:1524 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0xc1828f Code: Unable to access opcode bytes at 0xc18265. RSP: 002b:0000200000000148 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007f3ee09b5fa0 RCX: 00007f3ee078e929 RDX: 0000000000000000 RSI: 0000200000000140 RDI: 0000000000000080 RBP: 00007f3ee0810b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f3ee09b5fa0 R15: 00007ffce41c0778