====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.6.442/6679 is trying to acquire lock: ffff0000df88cae0 (&sdp->sd_quota_mutex){+.+.}-{3:3}, at: do_qc+0xb8/0x648 fs/gfs2/quota.c:682 but task is already holding lock: ffff0000fedc0ca0 (&ip->i_rw_mutex){++++}-{3:3}, at: gfs2_unstuff_dinode+0xa8/0xfbc 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+0x64/0x304 kernel/locking/rwsem.c:1520 __gfs2_iomap_get+0x10c/0x100c fs/gfs2/bmap.c:856 gfs2_iomap_get+0xc0/0x120 fs/gfs2/bmap.c:1396 bh_get+0x1d8/0x5e4 fs/gfs2/quota.c:385 qdsb_get+0x1d4/0x37c fs/gfs2/quota.c:522 gfs2_quota_hold+0x16c/0x558 fs/gfs2/quota.c:608 gfs2_quota_lock+0xbc/0x748 fs/gfs2/quota.c:1076 gfs2_quota_lock_check fs/gfs2/quota.h:50 [inline] do_grow fs/gfs2/bmap.c:2063 [inline] gfs2_setattr_size+0x2e0/0x670 fs/gfs2/bmap.c:2138 gfs2_setattr+0x230/0x3a8 fs/gfs2/inode.c:2003 notify_change+0xb0c/0xdcc fs/attr.c:499 do_truncate+0x178/0x1f0 fs/open.c:65 do_sys_ftruncate+0x284/0x31c fs/open.c:193 __do_sys_ftruncate fs/open.c:204 [inline] __se_sys_ftruncate fs/open.c:202 [inline] __arm64_sys_ftruncate+0x60/0x74 fs/open.c:202 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x138 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+0x293c/0x6544 kernel/locking/lockdep.c:5049 lock_acquire+0x20c/0x644 kernel/locking/lockdep.c:5662 __mutex_lock_common+0x190/0x1f38 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+0xb8/0x648 fs/gfs2/quota.c:682 gfs2_quota_change+0x238/0x718 fs/gfs2/quota.c:1295 gfs2_alloc_blocks+0x13bc/0x1abc fs/gfs2/rgrp.c:2494 __gfs2_unstuff_inode fs/gfs2/bmap.c:109 [inline] gfs2_unstuff_dinode+0x1a4/0xfbc fs/gfs2/bmap.c:168 do_grow fs/gfs2/bmap.c:2082 [inline] gfs2_setattr_size+0x28c/0x670 fs/gfs2/bmap.c:2138 gfs2_setattr+0x230/0x3a8 fs/gfs2/inode.c:2003 notify_change+0xb0c/0xdcc fs/attr.c:499 do_truncate+0x178/0x1f0 fs/open.c:65 do_sys_ftruncate+0x284/0x31c fs/open.c:193 __do_sys_ftruncate fs/open.c:204 [inline] __se_sys_ftruncate fs/open.c:202 [inline] __arm64_sys_ftruncate+0x60/0x74 fs/open.c:202 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x138 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.6.442/6679: #0: ffff0000fada0460 (sb_writers#34){.+.+}-{0:0}, at: do_sys_ftruncate+0x210/0x31c fs/open.c:190 #1: ffff0000fedc0808 (&sb->s_type->i_mutex_key#37){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #1: ffff0000fedc0808 (&sb->s_type->i_mutex_key#37){+.+.}-{3:3}, at: do_truncate+0x164/0x1f0 fs/open.c:63 #2: ffff0000fada0650 (sb_internal#7){.+.+}-{0:0}, at: gfs2_trans_begin+0xa8/0x114 fs/gfs2/trans.c:118 #3: ffff0000df88d058 (&sdp->sd_log_flush_lock){++++}-{3:3}, at: __gfs2_trans_begin+0x4f0/0x85c fs/gfs2/trans.c:87 #4: ffff0000fedc0ca0 (&ip->i_rw_mutex){++++}-{3:3}, at: gfs2_unstuff_dinode+0xa8/0xfbc fs/gfs2/bmap.c:163 stack backtrace: CPU: 1 PID: 6679 Comm: syz.6.442 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025 Call trace: dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __dump_stack+0x30/0x40 lib/dump_stack.c:88 dump_stack_lvl+0xf8/0x160 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+0x240/0x2d4 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+0x293c/0x6544 kernel/locking/lockdep.c:5049 lock_acquire+0x20c/0x644 kernel/locking/lockdep.c:5662 __mutex_lock_common+0x190/0x1f38 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+0xb8/0x648 fs/gfs2/quota.c:682 gfs2_quota_change+0x238/0x718 fs/gfs2/quota.c:1295 gfs2_alloc_blocks+0x13bc/0x1abc fs/gfs2/rgrp.c:2494 __gfs2_unstuff_inode fs/gfs2/bmap.c:109 [inline] gfs2_unstuff_dinode+0x1a4/0xfbc fs/gfs2/bmap.c:168 do_grow fs/gfs2/bmap.c:2082 [inline] gfs2_setattr_size+0x28c/0x670 fs/gfs2/bmap.c:2138 gfs2_setattr+0x230/0x3a8 fs/gfs2/inode.c:2003 notify_change+0xb0c/0xdcc fs/attr.c:499 do_truncate+0x178/0x1f0 fs/open.c:65 do_sys_ftruncate+0x284/0x31c fs/open.c:193 __do_sys_ftruncate fs/open.c:204 [inline] __se_sys_ftruncate fs/open.c:202 [inline] __arm64_sys_ftruncate+0x60/0x74 fs/open.c:202 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x138 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