====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.1.98/4986 is trying to acquire lock: ffff0000f61d8ae0 (&sdp->sd_quota_mutex){+.+.}-{3:3}, at: do_qc+0xbc/0x648 fs/gfs2/quota.c:682 but task is already holding lock: ffff0000fd81a780 (&ip->i_rw_mutex){++++}-{3:3}, at: sweep_bh_for_rgrps fs/gfs2/bmap.c:1529 [inline] ffff0000fd81a780 (&ip->i_rw_mutex){++++}-{3:3}, at: punch_hole+0x20d8/0x2e88 fs/gfs2/bmap.c:1854 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+0x64/0x300 kernel/locking/rwsem.c:1520 __gfs2_iomap_get+0x114/0x1044 fs/gfs2/bmap.c:862 gfs2_iomap_get+0xd4/0x144 fs/gfs2/bmap.c:1413 bh_get+0x1e4/0x604 fs/gfs2/quota.c:385 qdsb_get+0x1d4/0x378 fs/gfs2/quota.c:522 gfs2_quota_hold+0x16c/0x558 fs/gfs2/quota.c:608 punch_hole+0xb74/0x2e88 fs/gfs2/bmap.c:1815 __gfs2_punch_hole+0x694/0x89c fs/gfs2/bmap.c:2469 gfs2_fallocate+0x384/0x494 fs/gfs2/file.c:1393 vfs_fallocate+0x4a4/0x5f4 fs/open.c:323 ioctl_preallocate+0x20c/0x2b4 fs/ioctl.c:290 file_ioctl fs/ioctl.c:-1 [inline] do_vfs_ioctl+0x1874/0x2100 fs/ioctl.c:849 __do_sys_ioctl fs/ioctl.c:868 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __arm64_sys_ioctl+0xe4/0x1c8 fs/ioctl.c:856 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 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+0x2880/0x6800 kernel/locking/lockdep.c:5049 lock_acquire+0x20c/0x63c kernel/locking/lockdep.c:5662 __mutex_lock_common+0x190/0x1f60 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/0x648 fs/gfs2/quota.c:682 gfs2_quota_change+0x238/0x718 fs/gfs2/quota.c:1295 punch_hole+0x2968/0x2e88 fs/gfs2/bmap.c:1955 __gfs2_punch_hole+0x694/0x89c fs/gfs2/bmap.c:2469 gfs2_fallocate+0x384/0x494 fs/gfs2/file.c:1393 vfs_fallocate+0x4a4/0x5f4 fs/open.c:323 ioctl_preallocate+0x20c/0x2b4 fs/ioctl.c:290 file_ioctl fs/ioctl.c:-1 [inline] do_vfs_ioctl+0x1874/0x2100 fs/ioctl.c:849 __do_sys_ioctl fs/ioctl.c:868 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __arm64_sys_ioctl+0xe4/0x1c8 fs/ioctl.c:856 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 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.1.98/4986: #0: ffff0000dc92c460 (sb_writers#23){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3015 [inline] #0: ffff0000dc92c460 (sb_writers#23){.+.+}-{0:0}, at: vfs_fallocate+0x434/0x5f4 fs/open.c:322 #1: ffff0000fd81a2e8 (&sb->s_type->i_mutex_key#27){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #1: ffff0000fd81a2e8 (&sb->s_type->i_mutex_key#27){+.+.}-{3:3}, at: gfs2_fallocate+0x190/0x494 fs/gfs2/file.c:1374 #2: ffff0000dc92c650 (sb_internal#6){.+.+}-{0:0}, at: gfs2_trans_begin+0xa8/0x114 fs/gfs2/trans.c:118 #3: ffff0000f61d9058 (&sdp->sd_log_flush_lock){.+.+}-{3:3}, at: __gfs2_trans_begin+0x500/0x870 fs/gfs2/trans.c:87 #4: ffff0000fd81a780 (&ip->i_rw_mutex){++++}-{3:3}, at: sweep_bh_for_rgrps fs/gfs2/bmap.c:1529 [inline] #4: ffff0000fd81a780 (&ip->i_rw_mutex){++++}-{3:3}, at: punch_hole+0x20d8/0x2e88 fs/gfs2/bmap.c:1854 stack backtrace: CPU: 0 PID: 4986 Comm: syz.1.98 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/26/2026 Call trace: dump_backtrace+0x1c0/0x1ec arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __dump_stack+0x30/0x40 lib/dump_stack.c:88 dump_stack_lvl+0xf4/0x15c lib/dump_stack.c:106 dump_stack+0x1c/0x5c lib/dump_stack.c:113 print_circular_bug+0x148/0x1b0 kernel/locking/lockdep.c:2048 check_noncircular+0x264/0x2f8 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+0x2880/0x6800 kernel/locking/lockdep.c:5049 lock_acquire+0x20c/0x63c kernel/locking/lockdep.c:5662 __mutex_lock_common+0x190/0x1f60 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/0x648 fs/gfs2/quota.c:682 gfs2_quota_change+0x238/0x718 fs/gfs2/quota.c:1295 punch_hole+0x2968/0x2e88 fs/gfs2/bmap.c:1955 __gfs2_punch_hole+0x694/0x89c fs/gfs2/bmap.c:2469 gfs2_fallocate+0x384/0x494 fs/gfs2/file.c:1393 vfs_fallocate+0x4a4/0x5f4 fs/open.c:323 ioctl_preallocate+0x20c/0x2b4 fs/ioctl.c:290 file_ioctl fs/ioctl.c:-1 [inline] do_vfs_ioctl+0x1874/0x2100 fs/ioctl.c:849 __do_sys_ioctl fs/ioctl.c:868 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __arm64_sys_ioctl+0xe4/0x1c8 fs/ioctl.c:856 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585