gfs2: fsid=syz:syz.0: found 1 quota changes
======================================================
WARNING: possible circular locking dependency detected
5.15.186-syzkaller #0 Not tainted
------------------------------------------------------
syz.0.1028/7772 is trying to acquire lock:
ffff0000c8b20ae0 (&sdp->sd_quota_mutex){+.+.}-{3:3}, at: do_qc+0xbc/0x690 fs/gfs2/quota.c:678

but task is already holding lock:
ffff0000ea435080 (&ip->i_rw_mutex){++++}-{3:3}, at: __gfs2_iomap_alloc+0x1e8/0x13dc fs/gfs2/bmap.c:681

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+0xc0/0x390 kernel/locking/rwsem.c:1498
       __gfs2_iomap_get+0x10c/0x100c fs/gfs2/bmap.c:858
       gfs2_iomap_get fs/gfs2/bmap.c:1398 [inline]
       gfs2_block_map+0x2b4/0xbc8 fs/gfs2/bmap.c:1213
       bh_get+0x1bc/0x51c fs/gfs2/quota.c:385
       qdsb_get+0x1e0/0x3a8 fs/gfs2/quota.c:518
       gfs2_quota_hold+0x16c/0x558 fs/gfs2/quota.c:604
       gfs2_quota_lock+0xbc/0x75c fs/gfs2/quota.c:1076
       gfs2_quota_lock_check fs/gfs2/quota.h:50 [inline]
       gfs2_iomap_begin_write fs/gfs2/bmap.c:1015 [inline]
       gfs2_iomap_begin+0x5dc/0x1198 fs/gfs2/bmap.c:1114
       iomap_iter+0x5ec/0xf20 fs/iomap/iter.c:74
       iomap_file_buffered_write+0x154/0x4f0 fs/iomap/buffered-io.c:814
       gfs2_file_buffered_write+0x3d0/0x880 fs/gfs2/file.c:1058
       gfs2_file_write_iter+0x39c/0xbd8 fs/gfs2/file.c:1166
       call_write_iter include/linux/fs.h:2172 [inline]
       new_sync_write fs/read_write.c:507 [inline]
       vfs_write+0x7c8/0xa2c fs/read_write.c:594
       ksys_write+0x120/0x210 fs/read_write.c:647
       __do_sys_write fs/read_write.c:659 [inline]
       __se_sys_write fs/read_write.c:656 [inline]
       __arm64_sys_write+0x7c/0x90 fs/read_write.c:656
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
       el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
       do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
       el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608
       el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626
       el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

-> #0 (&sdp->sd_quota_mutex){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3053 [inline]
       check_prevs_add kernel/locking/lockdep.c:3172 [inline]
       validate_chain kernel/locking/lockdep.c:3788 [inline]
       __lock_acquire+0x2928/0x651c kernel/locking/lockdep.c:5012
       lock_acquire+0x1f4/0x620 kernel/locking/lockdep.c:5623
       __mutex_lock_common+0x194/0x1edc kernel/locking/mutex.c:596
       __mutex_lock kernel/locking/mutex.c:729 [inline]
       mutex_lock_nested+0xac/0x11c kernel/locking/mutex.c:743
       do_qc+0xbc/0x690 fs/gfs2/quota.c:678
       gfs2_quota_change+0x238/0x718 fs/gfs2/quota.c:1295
       gfs2_alloc_blocks+0x1398/0x1e78 fs/gfs2/rgrp.c:2504
       __gfs2_iomap_alloc+0x37c/0x13dc fs/gfs2/bmap.c:707
       gfs2_iomap_begin_write fs/gfs2/bmap.c:1049 [inline]
       gfs2_iomap_begin+0x948/0x1198 fs/gfs2/bmap.c:1114
       iomap_iter+0x5ec/0xf20 fs/iomap/iter.c:74
       iomap_file_buffered_write+0x154/0x4f0 fs/iomap/buffered-io.c:814
       gfs2_file_buffered_write+0x3d0/0x880 fs/gfs2/file.c:1058
       gfs2_file_write_iter+0x39c/0xbd8 fs/gfs2/file.c:1166
       call_write_iter include/linux/fs.h:2172 [inline]
       new_sync_write fs/read_write.c:507 [inline]
       vfs_write+0x7c8/0xa2c fs/read_write.c:594
       ksys_write+0x120/0x210 fs/read_write.c:647
       __do_sys_write fs/read_write.c:659 [inline]
       __se_sys_write fs/read_write.c:656 [inline]
       __arm64_sys_write+0x7c/0x90 fs/read_write.c:656
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
       el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
       do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
       el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608
       el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626
       el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

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 ***

6 locks held by syz.0.1028/7772:
 #0: ffff0000c7ef4870 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x118/0x170 fs/file.c:1058
 #1: ffff0000f1aba460 (sb_writers#31){.+.+}-{0:0}, at: vfs_write+0x228/0xa2c fs/read_write.c:590
 #2: ffff0000ea434be8 (&sb->s_type->i_mutex_key#36){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #2: ffff0000ea434be8 (&sb->s_type->i_mutex_key#36){+.+.}-{3:3}, at: gfs2_file_write_iter+0x28c/0xbd8 fs/gfs2/file.c:1123
 #3: ffff0000f1aba650 (sb_internal#7){.+.+}-{0:0}, at: gfs2_trans_begin+0x120/0x1bc fs/gfs2/trans.c:118
 #4: ffff0000c8b210a8 (&sdp->sd_log_flush_lock){.+.+}-{3:3}, at: __gfs2_trans_begin+0x558/0x8fc fs/gfs2/trans.c:87
 #5: ffff0000ea435080 (&ip->i_rw_mutex){++++}-{3:3}, at: __gfs2_iomap_alloc+0x1e8/0x13dc fs/gfs2/bmap.c:681

stack backtrace:
CPU: 0 PID: 7772 Comm: syz.0.1028 Not tainted 5.15.186-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call trace:
 dump_backtrace+0x0/0x43c arch/arm64/kernel/stacktrace.c:152
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216
 __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:2011
 check_noncircular+0x240/0x2d4 kernel/locking/lockdep.c:2133
 check_prev_add kernel/locking/lockdep.c:3053 [inline]
 check_prevs_add kernel/locking/lockdep.c:3172 [inline]
 validate_chain kernel/locking/lockdep.c:3788 [inline]
 __lock_acquire+0x2928/0x651c kernel/locking/lockdep.c:5012
 lock_acquire+0x1f4/0x620 kernel/locking/lockdep.c:5623
 __mutex_lock_common+0x194/0x1edc kernel/locking/mutex.c:596
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0xac/0x11c kernel/locking/mutex.c:743
 do_qc+0xbc/0x690 fs/gfs2/quota.c:678
 gfs2_quota_change+0x238/0x718 fs/gfs2/quota.c:1295
 gfs2_alloc_blocks+0x1398/0x1e78 fs/gfs2/rgrp.c:2504
 __gfs2_iomap_alloc+0x37c/0x13dc fs/gfs2/bmap.c:707
 gfs2_iomap_begin_write fs/gfs2/bmap.c:1049 [inline]
 gfs2_iomap_begin+0x948/0x1198 fs/gfs2/bmap.c:1114
 iomap_iter+0x5ec/0xf20 fs/iomap/iter.c:74
 iomap_file_buffered_write+0x154/0x4f0 fs/iomap/buffered-io.c:814
 gfs2_file_buffered_write+0x3d0/0x880 fs/gfs2/file.c:1058
 gfs2_file_write_iter+0x39c/0xbd8 fs/gfs2/file.c:1166
 call_write_iter include/linux/fs.h:2172 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0x7c8/0xa2c fs/read_write.c:594
 ksys_write+0x120/0x210 fs/read_write.c:647
 __do_sys_write fs/read_write.c:659 [inline]
 __se_sys_write fs/read_write.c:656 [inline]
 __arm64_sys_write+0x7c/0x90 fs/read_write.c:656
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
==================================================================
BUG: KASAN: stack-out-of-bounds in should_fault_in_pages fs/gfs2/file.c:785 [inline]
BUG: KASAN: stack-out-of-bounds in gfs2_file_buffered_write+0x4bc/0x880 fs/gfs2/file.c:1070
Read of size 8 at addr ffff8000201f7b50 by task syz.0.1028/7772

CPU: 0 PID: 7772 Comm: syz.0.1028 Not tainted 5.15.186-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call trace:
 dump_backtrace+0x0/0x43c arch/arm64/kernel/stacktrace.c:152
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216
 __dump_stack+0x30/0x40 lib/dump_stack.c:88
 dump_stack_lvl+0xf8/0x160 lib/dump_stack.c:106
 print_address_description+0x78/0x30c mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0xec/0x15c mm/kasan/report.c:451
 __asan_report_load8_noabort+0x44/0x50 mm/kasan/report_generic.c:309
 should_fault_in_pages fs/gfs2/file.c:785 [inline]
 gfs2_file_buffered_write+0x4bc/0x880 fs/gfs2/file.c:1070
 gfs2_file_write_iter+0x39c/0xbd8 fs/gfs2/file.c:1166
 call_write_iter include/linux/fs.h:2172 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0x7c8/0xa2c fs/read_write.c:594
 ksys_write+0x120/0x210 fs/read_write.c:647
 __do_sys_write fs/read_write.c:659 [inline]
 __se_sys_write fs/read_write.c:656 [inline]
 __arm64_sys_write+0x7c/0x90 fs/read_write.c:656
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584


addr ffff8000201f7b50 is located in stack of task syz.0.1028/7772 at offset 48 in frame:
 percpu_up_read include/linux/percpu-rwsem.h:-1 [inline]
 __sb_end_write include/linux/fs.h:1806 [inline]
 vfs_write+0x0/0xa2c include/linux/fs.h:3056

this frame has 3 objects:
 [32, 48) 'iov.i'
 [64, 112) 'kiocb.i'
 [144, 184) 'iter.i'

Memory state around the buggy address:
 ffff8000201f7a00: 00 00 00 00 00 00 00 f3 f3 f3 f3 f3 00 00 00 00
 ffff8000201f7a80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8000201f7b00: 00 00 00 00 f1 f1 f1 f1 00 00 f2 f2 00 00 00 00
                                                 ^
 ffff8000201f7b80: 00 00 f2 f2 f2 f2 00 00 00 00 00 f3 f3 f3 f3 f3
 ffff8000201f7c00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================