======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.3.64/6180 is trying to acquire lock:
ffff8880250b8ae8 (&sdp->sd_quota_mutex){+.+.}-{3:3}, at: do_qc+0xa1/0x5f0 fs/gfs2/quota.c:689

but task is already holding lock:
ffff88805e8f3ba8 (&ip->i_rw_mutex){++++}-{3:3}, at: sweep_bh_for_rgrps fs/gfs2/bmap.c:1543 [inline]
ffff88805e8f3ba8 (&ip->i_rw_mutex){++++}-{3:3}, at: punch_hole+0x1c8e/0x2e00 fs/gfs2/bmap.c:1867

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+0x168/0x1390 fs/gfs2/bmap.c:862
       gfs2_iomap_get+0xef/0x170 fs/gfs2/bmap.c:1427
       bh_get+0x251/0x760 fs/gfs2/quota.c:401
       qdsb_get+0x210/0x330 fs/gfs2/quota.c:535
       gfs2_quota_hold+0x191/0x5c0 fs/gfs2/quota.c:615
       ea_remove_unstuffed fs/gfs2/xattr.c:338 [inline]
       ea_set_remove_unstuffed+0x182/0x280 fs/gfs2/xattr.c:1086
       __gfs2_xattr_set+0x8b5/0xb20 fs/gfs2/xattr.c:1217
       gfs2_xattr_set+0x341/0x430 fs/gfs2/xattr.c:1258
       __vfs_setxattr+0x437/0x470 fs/xattr.c:201
       __vfs_setxattr_noperm+0x12a/0x5e0 fs/xattr.c:235
       vfs_setxattr+0x16b/0x2f0 fs/xattr.c:322
       do_setxattr fs/xattr.c:630 [inline]
       path_setxattr+0x33a/0x590 fs/xattr.c:659
       __do_sys_setxattr fs/xattr.c:677 [inline]
       __se_sys_setxattr fs/xattr.c:673 [inline]
       __x64_sys_setxattr+0xbb/0xd0 fs/xattr.c:673
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #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+0x37ef/0x7d80 kernel/locking/lockdep.c:5137
       lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x135/0xc80 kernel/locking/mutex.c:747
       do_qc+0xa1/0x5f0 fs/gfs2/quota.c:689
       gfs2_quota_change+0x28f/0x7a0 fs/gfs2/quota.c:1289
       punch_hole+0x282f/0x2e00 fs/gfs2/bmap.c:1968
       gfs2_iomap_end+0x4a5/0x7b0 fs/gfs2/bmap.c:1188
       iomap_iter+0x203/0xe70 fs/iomap/iter.c:79
       iomap_file_buffered_write+0xbc8/0xda0 fs/iomap/buffered-io.c:1007
       gfs2_file_buffered_write+0x4c0/0x820 fs/gfs2/file.c:1060
       gfs2_file_write_iter+0x43d/0xe90 fs/gfs2/file.c:1158
       __kernel_write_iter+0x29f/0x6d0 fs/read_write.c:517
       dump_emit_page fs/coredump.c:958 [inline]
       dump_user_range+0x418/0x840 fs/coredump.c:985
       elf_core_dump+0x320e/0x37c0 fs/binfmt_elf.c:2184
       do_coredump+0x1791/0x24a0 fs/coredump.c:834
       get_signal+0x10da/0x1390 kernel/signal.c:2897
       arch_do_signal_or_restart+0xc2/0x7b0 arch/x86/kernel/signal.c:310
       exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
       exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
       irqentry_exit_to_user_mode+0x9/0x30 kernel/entry/common.c:315
       exc_page_fault+0x8c/0x100 arch/x86/mm/fault.c:1519
       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.3.64/6180:
 #0: ffff888030b7c418 (sb_writers#22){.+.+}-{0:0}, at: do_coredump+0x1774/0x24a0 fs/coredump.c:833
 #1: ffff88805e8f3720 (&sb->s_type->i_mutex_key#26){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
 #1: ffff88805e8f3720 (&sb->s_type->i_mutex_key#26){+.+.}-{3:3}, at: gfs2_file_write_iter+0x364/0xe90 fs/gfs2/file.c:1115
 #2: ffff888030b7c608 (sb_internal#5){.+.+}-{0:0}, at: gfs2_trans_begin+0x6f/0xe0 fs/gfs2/trans.c:118
 #3: ffff8880250b9060 (&sdp->sd_log_flush_lock){.+.+}-{3:3}, at: __gfs2_trans_begin+0x537/0x8b0 fs/gfs2/trans.c:87
 #4: ffff88805e8f3ba8 (&ip->i_rw_mutex){++++}-{3:3}, at: sweep_bh_for_rgrps fs/gfs2/bmap.c:1543 [inline]
 #4: ffff88805e8f3ba8 (&ip->i_rw_mutex){++++}-{3:3}, at: punch_hole+0x1c8e/0x2e00 fs/gfs2/bmap.c:1867

stack backtrace:
CPU: 1 PID: 6180 Comm: syz.3.64 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 check_noncircular+0x2fc/0x400 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+0x37ef/0x7d80 kernel/locking/lockdep.c:5137
 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
 __mutex_lock_common kernel/locking/mutex.c:603 [inline]
 __mutex_lock+0x135/0xc80 kernel/locking/mutex.c:747
 do_qc+0xa1/0x5f0 fs/gfs2/quota.c:689
 gfs2_quota_change+0x28f/0x7a0 fs/gfs2/quota.c:1289
 punch_hole+0x282f/0x2e00 fs/gfs2/bmap.c:1968
 gfs2_iomap_end+0x4a5/0x7b0 fs/gfs2/bmap.c:1188
 iomap_iter+0x203/0xe70 fs/iomap/iter.c:79
 iomap_file_buffered_write+0xbc8/0xda0 fs/iomap/buffered-io.c:1007
 gfs2_file_buffered_write+0x4c0/0x820 fs/gfs2/file.c:1060
 gfs2_file_write_iter+0x43d/0xe90 fs/gfs2/file.c:1158
 __kernel_write_iter+0x29f/0x6d0 fs/read_write.c:517
 dump_emit_page fs/coredump.c:958 [inline]
 dump_user_range+0x418/0x840 fs/coredump.c:985
 elf_core_dump+0x320e/0x37c0 fs/binfmt_elf.c:2184
 do_coredump+0x1791/0x24a0 fs/coredump.c:834
 get_signal+0x10da/0x1390 kernel/signal.c:2897
 arch_do_signal_or_restart+0xc2/0x7b0 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
 irqentry_exit_to_user_mode+0x9/0x30 kernel/entry/common.c:315
 exc_page_fault+0x8c/0x100 arch/x86/mm/fault.c:1519
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0033:0x7f4dd499e161
Code: 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 48 3d 01 f0 ff ff 73 01 <c3> 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f
RSP: 002b:0000000000000050 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f4dd4c25fa0 RCX: 00007f4dd499e159
RDX: 0000000000000000 RSI: 0000000000000050 RDI: 0000000000904000
RBP: 00007f4dd4a35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f4dd4c26038 R14: 00007f4dd4c25fa0 R15: 00007ffffb8b0c48
 </TASK>