====================================================== WARNING: possible circular locking dependency detected 6.1.132-syzkaller #0 Not tainted ------------------------------------------------------ syz.4.49/4690 is trying to acquire lock: ffff0000c37c8ae0 (&sdp->sd_quota_mutex){+.+.}-{3:3}, at: do_qc+0xbc/0x664 fs/gfs2/quota.c:682 but task is already holding lock: ffff0000e12e4fd0 (&ip->i_rw_mutex){++++}-{3:3}, at: sweep_bh_for_rgrps fs/gfs2/bmap.c:1512 [inline] ffff0000e12e4fd0 (&ip->i_rw_mutex){++++}-{3:3}, at: punch_hole+0x2268/0x30dc 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+0x64/0x308 kernel/locking/rwsem.c:1520 __gfs2_iomap_get+0x138/0x1058 fs/gfs2/bmap.c:856 gfs2_iomap_get+0xd8/0x154 fs/gfs2/bmap.c:1396 bh_get+0x208/0x6ac fs/gfs2/quota.c:385 qdsb_get+0x1e0/0x398 fs/gfs2/quota.c:522 gfs2_quota_hold+0x16c/0x558 fs/gfs2/quota.c:608 punch_hole+0xbf8/0x30dc fs/gfs2/bmap.c:1798 gfs2_iomap_end+0x448/0x618 fs/gfs2/bmap.c:1157 iomap_iter+0x1fc/0x1218 fs/iomap/iter.c:79 iomap_file_buffered_write+0x7a8/0x940 fs/iomap/buffered-io.c:846 gfs2_file_buffered_write+0x49c/0x800 fs/gfs2/file.c:1057 gfs2_file_write_iter+0x3d4/0xc3c fs/gfs2/file.c:1158 __kernel_write_iter+0x264/0x600 fs/read_write.c:517 dump_emit_page fs/coredump.c:881 [inline] dump_user_range+0x384/0x6b8 fs/coredump.c:908 elf_core_dump+0x3020/0x3778 fs/binfmt_elf.c:2313 do_coredump+0x14a0/0x2234 fs/coredump.c:755 get_signal+0xf74/0x1528 kernel/signal.c:2857 do_signal arch/arm64/kernel/signal.c:1076 [inline] do_notify_resume+0x2f8/0x2cb8 arch/arm64/kernel/signal.c:1129 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] el0_da+0xb8/0x184 arch/arm64/kernel/entry-common.c:516 el0t_64_sync_handler+0xcc/0xf0 arch/arm64/kernel/entry-common.c:658 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 -> #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+0x3338/0x7680 kernel/locking/lockdep.c:5049 lock_acquire+0x26c/0x7cc kernel/locking/lockdep.c:5662 __mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799 do_qc+0xbc/0x664 fs/gfs2/quota.c:682 gfs2_quota_change+0x238/0x718 fs/gfs2/quota.c:1295 punch_hole+0x2b4c/0x30dc fs/gfs2/bmap.c:1938 gfs2_iomap_end+0x448/0x618 fs/gfs2/bmap.c:1157 iomap_iter+0x1fc/0x1218 fs/iomap/iter.c:79 iomap_file_buffered_write+0x7a8/0x940 fs/iomap/buffered-io.c:846 gfs2_file_buffered_write+0x49c/0x800 fs/gfs2/file.c:1057 gfs2_file_write_iter+0x3d4/0xc3c fs/gfs2/file.c:1158 __kernel_write_iter+0x264/0x600 fs/read_write.c:517 dump_emit_page fs/coredump.c:881 [inline] dump_user_range+0x384/0x6b8 fs/coredump.c:908 elf_core_dump+0x3020/0x3778 fs/binfmt_elf.c:2313 do_coredump+0x14a0/0x2234 fs/coredump.c:755 get_signal+0xf74/0x1528 kernel/signal.c:2857 do_signal arch/arm64/kernel/signal.c:1076 [inline] do_notify_resume+0x2f8/0x2cb8 arch/arm64/kernel/signal.c:1129 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] el0_da+0xb8/0x184 arch/arm64/kernel/entry-common.c:516 el0t_64_sync_handler+0xcc/0xf0 arch/arm64/kernel/entry-common.c:658 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 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.4.49/4690: #0: ffff0000dc9aa460 (sb_writers#18){.+.+}-{0:0}, at: do_coredump+0x1478/0x2234 fs/coredump.c:754 #1: ffff0000e12e4b38 (&sb->s_type->i_mutex_key#25){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #1: ffff0000e12e4b38 (&sb->s_type->i_mutex_key#25){+.+.}-{3:3}, at: gfs2_file_write_iter+0x2cc/0xc3c fs/gfs2/file.c:1115 #2: ffff0000dc9aa650 (sb_internal#5){.+.+}-{0:0}, at: gfs2_trans_begin+0xa8/0x11c fs/gfs2/trans.c:118 #3: ffff0000c37c9058 (&sdp->sd_log_flush_lock){.+.+}-{3:3}, at: __gfs2_trans_begin+0x524/0x91c fs/gfs2/trans.c:87 #4: ffff0000e12e4fd0 (&ip->i_rw_mutex){++++}-{3:3}, at: sweep_bh_for_rgrps fs/gfs2/bmap.c:1512 [inline] #4: ffff0000e12e4fd0 (&ip->i_rw_mutex){++++}-{3:3}, at: punch_hole+0x2268/0x30dc fs/gfs2/bmap.c:1837 stack backtrace: CPU: 1 PID: 4690 Comm: syz.4.49 Not tainted 6.1.132-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call trace: dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106 dump_stack+0x1c/0x5c lib/dump_stack.c:113 print_circular_bug+0x150/0x1b8 kernel/locking/lockdep.c:2048 check_noncircular+0x2cc/0x378 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+0x3338/0x7680 kernel/locking/lockdep.c:5049 lock_acquire+0x26c/0x7cc kernel/locking/lockdep.c:5662 __mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799 do_qc+0xbc/0x664 fs/gfs2/quota.c:682 gfs2_quota_change+0x238/0x718 fs/gfs2/quota.c:1295 punch_hole+0x2b4c/0x30dc fs/gfs2/bmap.c:1938 gfs2_iomap_end+0x448/0x618 fs/gfs2/bmap.c:1157 iomap_iter+0x1fc/0x1218 fs/iomap/iter.c:79 iomap_file_buffered_write+0x7a8/0x940 fs/iomap/buffered-io.c:846 gfs2_file_buffered_write+0x49c/0x800 fs/gfs2/file.c:1057 gfs2_file_write_iter+0x3d4/0xc3c fs/gfs2/file.c:1158 __kernel_write_iter+0x264/0x600 fs/read_write.c:517 dump_emit_page fs/coredump.c:881 [inline] dump_user_range+0x384/0x6b8 fs/coredump.c:908 elf_core_dump+0x3020/0x3778 fs/binfmt_elf.c:2313 do_coredump+0x14a0/0x2234 fs/coredump.c:755 get_signal+0xf74/0x1528 kernel/signal.c:2857 do_signal arch/arm64/kernel/signal.c:1076 [inline] do_notify_resume+0x2f8/0x2cb8 arch/arm64/kernel/signal.c:1129 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] el0_da+0xb8/0x184 arch/arm64/kernel/entry-common.c:516 el0t_64_sync_handler+0xcc/0xf0 arch/arm64/kernel/entry-common.c:658 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 bridge0: port 3(syz_tun) entered disabled state device syz_tun left promiscuous mode bridge0: port 3(syz_tun) entered disabled state