Re: [syzbot] [gfs2?] INFO: task hung in gfs2_recover_journal (4)

Re: [syzbot] [gfs2?] INFO: task hung in gfs2_recover_journal (4)

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
WARNING in gfs2_fill_super

loop1: detected capacity change from 0 to 32768
------------[ cut here ]------------
kmem_cache of name 'gfs2-bufdata/syz:syz' already exists
WARNING: mm/slab_common.c:112 at kmem_cache_sanity_check mm/slab_common.c:111 [inline], CPU#0: syz.1.18/6515
WARNING: mm/slab_common.c:112 at __kmem_cache_create_args+0xac/0x440 mm/slab_common.c:352, CPU#0: syz.1.18/6515
Modules linked in:
CPU: 0 UID: 0 PID: 6515 Comm: syz.1.18 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:kmem_cache_sanity_check mm/slab_common.c:111 [inline]
RIP: 0010:__kmem_cache_create_args+0xaf/0x440 mm/slab_common.c:352
Code: 86 8e 4d 8b 24 24 49 81 fc 18 68 86 8e 74 20 49 8b 7c 24 f8 48 89 de e8 3f 5c 9c 09 85 c0 75 e2 48 8d 3d 54 70 06 0e 48 89 de <67> 48 0f b9 3a 48 89 df be 20 00 00 00 e8 df 5d 9c 09 48 85 c0 0f
RSP: 0018:ffffc90003407948 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8880563c5040 RCX: 0000000000000005
RDX: 00000000563c5004 RSI: ffff8880563c5040 RDI: ffffffff9016e0b0
RBP: 0000000000000000 R08: ffffffff901246f7 R09: 1ffffffff20248de
R10: dffffc0000000000 R11: fffffbfff20248df R12: ffff88814a3b6a60
R13: ffff888035dd4000 R14: 0000000000000050 R15: ffffc90003407a60
FS:  00007fdcb83716c0(0000) GS:ffff888125448000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdcb7585900 CR3: 000000005e392000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __kmem_cache_create include/linux/slab.h:390 [inline]
 gfs2_fill_super+0x13a7/0x21f0 fs/gfs2/ops_fstype.c:1202
 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694
 gfs2_get_tree+0x51/0x1e0 fs/gfs2/ops_fstype.c:1343
 vfs_get_tree+0x92/0x2a0 fs/super.c:1754
 fc_mount fs/namespace.c:1193 [inline]
 do_new_mount_fc fs/namespace.c:3764 [inline]
 do_new_mount+0x341/0xd30 fs/namespace.c:3840
 do_mount fs/namespace.c:4173 [inline]
 __do_sys_mount fs/namespace.c:4372 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4349
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdcb759da0a
Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fdcb8370e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fdcb8370ee0 RCX: 00007fdcb759da0a
RDX: 0000200000037f40 RSI: 0000200000037f80 RDI: 00007fdcb8370ea0
RBP: 0000200000037f40 R08: 00007fdcb8370ee0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000037f80
R13: 00007fdcb8370ea0 R14: 0000000000037fc4 R15: 0000200000000300
 </TASK>
----------------
Code disassembly (best guess):
   0:	86 8e 4d 8b 24 24    	xchg   %cl,0x24248b4d(%rsi)
   6:	49 81 fc 18 68 86 8e 	cmp    $0xffffffff8e866818,%r12
   d:	74 20                	je     0x2f
   f:	49 8b 7c 24 f8       	mov    -0x8(%r12),%rdi
  14:	48 89 de             	mov    %rbx,%rsi
  17:	e8 3f 5c 9c 09       	call   0x99c5c5b
  1c:	85 c0                	test   %eax,%eax
  1e:	75 e2                	jne    0x2
  20:	48 8d 3d 54 70 06 0e 	lea    0xe067054(%rip),%rdi        # 0xe06707b
  27:	48 89 de             	mov    %rbx,%rsi
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	48 89 df             	mov    %rbx,%rdi
  32:	be 20 00 00 00       	mov    $0x20,%esi
  37:	e8 df 5d 9c 09       	call   0x99c5e1b
  3c:	48 85 c0             	test   %rax,%rax
  3f:	0f                   	.byte 0xf


Tested on:

commit:         09c0f7f1 Add linux-next specific files for 20260323
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=10f39e16580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c0c30527ccbcb0f2
dashboard link: https://syzkaller.appspot.com/bug?extid=9013411dc43f3582823a
compiler:       Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
patch:          https://syzkaller.appspot.com/x/patch.diff?x=132fc1d6580000

Re: [syzbot] [gfs2?] INFO: task hung in gfs2_recover_journal (4)

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-use-after-free Read in gfs2_invalidate_folio

RBP: 00007ffd3cccca40 R08: 00007ffd3cccda40 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd3cccdad0
R13: 00007f2a75832050 R14: 0000000000020287 R15: 00007ffd3cccdb10
 </TASK>
gfs2: fsid=syz:syz.0: gfs2_evict_inode: -5
==================================================================
BUG: KASAN: slab-use-after-free in list_empty include/linux/list.h:381 [inline]
BUG: KASAN: slab-use-after-free in gfs2_discard fs/gfs2/aops.c:590 [inline]
BUG: KASAN: slab-use-after-free in gfs2_invalidate_folio+0x40b/0x750 fs/gfs2/aops.c:628
Read of size 8 at addr ffff88804e6038d8 by task syz-executor/6493

CPU: 0 UID: 0 PID: 6493 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 list_empty include/linux/list.h:381 [inline]
 gfs2_discard fs/gfs2/aops.c:590 [inline]
 gfs2_invalidate_folio+0x40b/0x750 fs/gfs2/aops.c:628
 folio_invalidate mm/truncate.c:140 [inline]
 truncate_cleanup_folio+0xcb/0x190 mm/truncate.c:160
 truncate_inode_pages_range+0x2ce/0xe30 mm/truncate.c:404
 gfs2_evict_inode+0xa60/0x1300 fs/gfs2/super.c:1459
 evict+0x61e/0xb10 fs/inode.c:846
 gfs2_put_super+0x355/0x890 fs/gfs2/super.c:619
 generic_shutdown_super+0x13d/0x2d0 fs/super.c:646
 kill_block_super+0x44/0x90 fs/super.c:1725
 deactivate_locked_super+0xbc/0x130 fs/super.c:476
 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
 exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
 do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2a7579d9d7
Code: a2 c7 05 1c fd 24 00 00 00 00 00 eb 96 e8 e1 12 00 00 90 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffd3cccc988 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f2a75832050 RCX: 00007f2a7579d9d7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd3cccca40
RBP: 00007ffd3cccca40 R08: 00007ffd3cccda40 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd3cccdad0
R13: 00007f2a75832050 R14: 0000000000020287 R15: 00007ffd3cccdb10
 </TASK>

Allocated by task 6493:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 unpoison_slab_object mm/kasan/common.c:340 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4569 [inline]
 slab_alloc_node mm/slub.c:4898 [inline]
 kmem_cache_alloc_noprof+0x2bc/0x650 mm/slub.c:4905
 gfs2_alloc_bufdata fs/gfs2/trans.c:176 [inline]
 gfs2_trans_add_data+0x1e8/0x610 fs/gfs2/trans.c:215
 gfs2_unstuffer_folio fs/gfs2/bmap.c:81 [inline]
 __gfs2_unstuff_inode fs/gfs2/bmap.c:119 [inline]
 gfs2_unstuff_dinode+0xace/0x1240 fs/gfs2/bmap.c:166
 gfs2_adjust_quota+0x23f/0x850 fs/gfs2/quota.c:848
 do_sync+0x872/0xcb0 fs/gfs2/quota.c:962
 gfs2_quota_sync+0x370/0x470 fs/gfs2/quota.c:1358
 gfs2_sync_fs+0x4c/0xb0 fs/gfs2/super.c:661
 sync_filesystem+0xee/0x230 fs/sync.c:56
 generic_shutdown_super+0x77/0x2d0 fs/super.c:625
 kill_block_super+0x44/0x90 fs/super.c:1725
 deactivate_locked_super+0xbc/0x130 fs/super.c:476
 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
 exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
 do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 6493:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2689 [inline]
 slab_free mm/slub.c:6242 [inline]
 kmem_cache_free+0x182/0x650 mm/slub.c:6369
 gfs2_trans_drain_list fs/gfs2/log.c:995 [inline]
 gfs2_trans_drain fs/gfs2/log.c:1013 [inline]
 gfs2_log_flush+0x18c1/0x2640 fs/gfs2/log.c:1185
 do_sync+0xa48/0xcb0 fs/gfs2/quota.c:982
 gfs2_quota_sync+0x370/0x470 fs/gfs2/quota.c:1358
 gfs2_sync_fs+0x4c/0xb0 fs/gfs2/super.c:661
 sync_filesystem+0xee/0x230 fs/sync.c:56
 generic_shutdown_super+0x77/0x2d0 fs/super.c:625
 kill_block_super+0x44/0x90 fs/super.c:1725
 deactivate_locked_super+0xbc/0x130 fs/super.c:476
 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
 exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
 do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88804e6038c0
 which belongs to the cache gfs2-bufdata/syz:syz of size 80
The buggy address is located 24 bytes inside of
 freed 80-byte region [ffff88804e6038c0, ffff88804e603910)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88804e603a80 pfn:0x4e603
flags: 0xfff00000000200(workingset|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000200 ffff888140adea00 ffff888034f85e88 ffff888034f85e88
raw: ffff88804e603a80 0000000800240018 00000000f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0xd2c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 6493, tgid 6493 (syz-executor), ts 131787600701, free_ts 125848846283
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x231/0x280 mm/page_alloc.c:1859
 prep_new_page mm/page_alloc.c:1867 [inline]
 get_page_from_freelist+0x2418/0x24b0 mm/page_alloc.c:3926
 __alloc_frozen_pages_noprof+0x233/0x3d0 mm/page_alloc.c:5213
 alloc_slab_page mm/slub.c:3278 [inline]
 allocate_slab+0x77/0x660 mm/slub.c:3467
 new_slab mm/slub.c:3525 [inline]
 refill_objects+0x339/0x3d0 mm/slub.c:7247
 refill_sheaf mm/slub.c:2816 [inline]
 __pcs_replace_empty_main+0x321/0x720 mm/slub.c:4651
 alloc_from_pcs mm/slub.c:4749 [inline]
 slab_alloc_node mm/slub.c:4883 [inline]
 kmem_cache_alloc_noprof+0x37d/0x650 mm/slub.c:4905
 gfs2_alloc_bufdata fs/gfs2/trans.c:176 [inline]
 gfs2_trans_add_meta+0x214/0x8e0 fs/gfs2/trans.c:279
 gfs2_alloc_extent fs/gfs2/rgrp.c:2237 [inline]
 gfs2_alloc_blocks+0x7ae/0x2090 fs/gfs2/rgrp.c:2447
 __gfs2_unstuff_inode fs/gfs2/bmap.c:107 [inline]
 gfs2_unstuff_dinode+0x249/0x1240 fs/gfs2/bmap.c:166
 gfs2_adjust_quota+0x23f/0x850 fs/gfs2/quota.c:848
 do_sync+0x872/0xcb0 fs/gfs2/quota.c:962
 gfs2_quota_sync+0x370/0x470 fs/gfs2/quota.c:1358
 gfs2_sync_fs+0x4c/0xb0 fs/gfs2/super.c:661
 sync_filesystem+0xee/0x230 fs/sync.c:56
 generic_shutdown_super+0x77/0x2d0 fs/super.c:625
page last free pid 6391 tgid 6391 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1403 [inline]
 __free_frozen_pages+0xbc7/0xd30 mm/page_alloc.c:2944
 vfree+0x1d1/0x2f0 mm/vmalloc.c:3472
 kcov_put kernel/kcov.c:442 [inline]
 kcov_close+0x28/0x50 kernel/kcov.c:543
 __fput+0x44f/0xa70 fs/file_table.c:469
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x70f/0x22c0 kernel/exit.c:974
 do_group_exit+0x21b/0x2d0 kernel/exit.c:1116
 get_signal+0x1284/0x1330 kernel/signal.c:3036
 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
 exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
 do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88804e603780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88804e603800: fc fc fc fc fc fc fc fc fc fc fa fb fb fb fb fb
>ffff88804e603880: fb fb fb fb fc fc fc fc fa fb fb fb fb fb fb fb
                                                    ^
 ffff88804e603900: fb fb fc fc fc fc fa fb fb fb fb fb fb fb fb fb
 ffff88804e603980: fc fc fc fc fa fb fb fb fb fb fb fb fb fb fc fc
==================================================================


Tested on:

commit:         09c0f7f1 Add linux-next specific files for 20260323
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
console output: https://syzkaller.appspot.com/x/log.txt?x=1277ac26580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c0c30527ccbcb0f2
dashboard link: https://syzkaller.appspot.com/bug?extid=9013411dc43f3582823a
compiler:       Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
patch:          https://syzkaller.appspot.com/x/patch.diff?x=11ced6da580000

Re: [syzbot] [gfs2?] INFO: task hung in gfs2_recover_journal (4)

[Edward Adam Davis]

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git 09c0f7f1bcdb

diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index 1cd8ec0bce83..fd11d5aa93b6 100644
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -2266,6 +2266,9 @@ int gfs2_map_journal_extents(struct gfs2_sbd *sdp, struct gfs2_jdesc *jd)
 	u64 size;
 	int rc;
 	ktime_t start, end;
+	struct super_block *sb = sdp->sd_vfs;
+	sector_t maxsector = bdev_nr_sectors(sb->s_bdev);
+	u32 bshift = sdp->sd_fsb2bb_shift;
 
 	start = ktime_get();
 	lblock_stop = i_size_read(jd->jd_inode) >> shift;
@@ -2280,6 +2283,10 @@ int gfs2_map_journal_extents(struct gfs2_sbd *sdp, struct gfs2_jdesc *jd)
 		rc = gfs2_block_map(jd->jd_inode, lblock, &bh, 0);
 		if (rc || !buffer_mapped(&bh))
 			goto fail;
+		if (bh.b_blocknr << bshift > maxsector) {
+			rc = -EIO;
+			goto fail;
+		}
 		rc = gfs2_add_jextent(jd, lblock, bh.b_blocknr, bh.b_size >> shift);
 		if (rc)
 			goto fail;

Re: [syzbot] [gfs2?] INFO: task hung in gfs2_recover_journal (4)

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-use-after-free Read in gfs2_invalidate_folio

RBP: 00007ffc7d4253b0 R08: 00007ffc7d4263b0 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc7d426440
R13: 00007f8d07e32050 R14: 0000000000025091 R15: 00007ffc7d426480
 </TASK>
gfs2: fsid=syz:syz.0: gfs2_evict_inode: -5
==================================================================
BUG: KASAN: slab-use-after-free in list_empty include/linux/list.h:381 [inline]
BUG: KASAN: slab-use-after-free in gfs2_discard fs/gfs2/aops.c:590 [inline]
BUG: KASAN: slab-use-after-free in gfs2_invalidate_folio+0x40b/0x750 fs/gfs2/aops.c:628
Read of size 8 at addr ffff88807e71e8d8 by task syz-executor/6427

CPU: 0 UID: 0 PID: 6427 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 list_empty include/linux/list.h:381 [inline]
 gfs2_discard fs/gfs2/aops.c:590 [inline]
 gfs2_invalidate_folio+0x40b/0x750 fs/gfs2/aops.c:628
 folio_invalidate mm/truncate.c:140 [inline]
 truncate_cleanup_folio+0xcb/0x190 mm/truncate.c:160
 truncate_inode_pages_range+0x2ce/0xe30 mm/truncate.c:404
 gfs2_evict_inode+0x9da/0x12d0 fs/gfs2/super.c:1476
 evict+0x61e/0xb10 fs/inode.c:846
 gfs2_put_super+0x355/0x890 fs/gfs2/super.c:619
 generic_shutdown_super+0x13d/0x2d0 fs/super.c:646
 kill_block_super+0x44/0x90 fs/super.c:1725
 deactivate_locked_super+0xbc/0x130 fs/super.c:476
 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
 exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
 do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8d07d9d9d7
Code: a2 c7 05 1c fd 24 00 00 00 00 00 eb 96 e8 e1 12 00 00 90 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffc7d4252f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f8d07e32050 RCX: 00007f8d07d9d9d7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc7d4253b0
RBP: 00007ffc7d4253b0 R08: 00007ffc7d4263b0 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc7d426440
R13: 00007f8d07e32050 R14: 0000000000025091 R15: 00007ffc7d426480
 </TASK>

Allocated by task 6427:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 unpoison_slab_object mm/kasan/common.c:340 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4569 [inline]
 slab_alloc_node mm/slub.c:4898 [inline]
 kmem_cache_alloc_noprof+0x2bc/0x650 mm/slub.c:4905
 gfs2_alloc_bufdata fs/gfs2/trans.c:176 [inline]
 gfs2_trans_add_data+0x1e8/0x610 fs/gfs2/trans.c:215
 gfs2_unstuffer_folio fs/gfs2/bmap.c:81 [inline]
 __gfs2_unstuff_inode fs/gfs2/bmap.c:119 [inline]
 gfs2_unstuff_dinode+0xace/0x1240 fs/gfs2/bmap.c:166
 gfs2_adjust_quota+0x23f/0x850 fs/gfs2/quota.c:848
 do_sync+0x872/0xcb0 fs/gfs2/quota.c:962
 gfs2_quota_sync+0x370/0x470 fs/gfs2/quota.c:1358
 gfs2_sync_fs+0x4c/0xb0 fs/gfs2/super.c:661
 sync_filesystem+0xee/0x230 fs/sync.c:56
 generic_shutdown_super+0x77/0x2d0 fs/super.c:625
 kill_block_super+0x44/0x90 fs/super.c:1725
 deactivate_locked_super+0xbc/0x130 fs/super.c:476
 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
 exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
 do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 6427:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2689 [inline]
 slab_free mm/slub.c:6242 [inline]
 kmem_cache_free+0x182/0x650 mm/slub.c:6369
 gfs2_trans_drain_list fs/gfs2/log.c:995 [inline]
 gfs2_trans_drain fs/gfs2/log.c:1013 [inline]
 gfs2_log_flush+0x18c1/0x2640 fs/gfs2/log.c:1185
 do_sync+0xa48/0xcb0 fs/gfs2/quota.c:982
 gfs2_quota_sync+0x370/0x470 fs/gfs2/quota.c:1358
 gfs2_sync_fs+0x4c/0xb0 fs/gfs2/super.c:661
 sync_filesystem+0xee/0x230 fs/sync.c:56
 generic_shutdown_super+0x77/0x2d0 fs/super.c:625
 kill_block_super+0x44/0x90 fs/super.c:1725
 deactivate_locked_super+0xbc/0x130 fs/super.c:476
 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
 exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
 do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88807e71e8c0
 which belongs to the cache gfs2-bufdata/syz:syz of size 80
The buggy address is located 24 bytes inside of
 freed 80-byte region [ffff88807e71e8c0, ffff88807e71e910)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88807e71ea80 pfn:0x7e71e
flags: 0xfff00000000200(workingset|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000200 ffff888141ad78c0 ffff8880307dde88 ffff8880307dde88
raw: ffff88807e71ea80 0000000800240018 00000000f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0xd2c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 6427, tgid 6427 (syz-executor), ts 151784205341, free_ts 151343117657
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x231/0x280 mm/page_alloc.c:1859
 prep_new_page mm/page_alloc.c:1867 [inline]
 get_page_from_freelist+0x2418/0x24b0 mm/page_alloc.c:3926
 __alloc_frozen_pages_noprof+0x233/0x3d0 mm/page_alloc.c:5213
 alloc_slab_page mm/slub.c:3278 [inline]
 allocate_slab+0x77/0x660 mm/slub.c:3467
 new_slab mm/slub.c:3525 [inline]
 refill_objects+0x339/0x3d0 mm/slub.c:7247
 refill_sheaf mm/slub.c:2816 [inline]
 __pcs_replace_empty_main+0x321/0x720 mm/slub.c:4651
 alloc_from_pcs mm/slub.c:4749 [inline]
 slab_alloc_node mm/slub.c:4883 [inline]
 kmem_cache_alloc_noprof+0x37d/0x650 mm/slub.c:4905
 gfs2_alloc_bufdata fs/gfs2/trans.c:176 [inline]
 gfs2_trans_add_meta+0x214/0x8e0 fs/gfs2/trans.c:279
 gfs2_alloc_extent fs/gfs2/rgrp.c:2237 [inline]
 gfs2_alloc_blocks+0x7ae/0x2090 fs/gfs2/rgrp.c:2447
 __gfs2_unstuff_inode fs/gfs2/bmap.c:107 [inline]
 gfs2_unstuff_dinode+0x249/0x1240 fs/gfs2/bmap.c:166
 gfs2_adjust_quota+0x23f/0x850 fs/gfs2/quota.c:848
 do_sync+0x872/0xcb0 fs/gfs2/quota.c:962
 gfs2_quota_sync+0x370/0x470 fs/gfs2/quota.c:1358
 gfs2_sync_fs+0x4c/0xb0 fs/gfs2/super.c:661
 sync_filesystem+0xee/0x230 fs/sync.c:56
 generic_shutdown_super+0x77/0x2d0 fs/super.c:625
page last free pid 6500 tgid 6499 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1403 [inline]
 free_unref_folios+0xcec/0x1480 mm/page_alloc.c:3005
 folios_put_refs+0x9ff/0xb40 mm/swap.c:1008
 folio_batch_release include/linux/folio_batch.h:101 [inline]
 truncate_inode_pages_range+0x3dd/0xe30 mm/truncate.c:408
 kill_bdev block/bdev.c:91 [inline]
 set_blocksize+0x2ce/0x440 block/bdev.c:207
 sb_set_blocksize+0xf8/0x240 block/bdev.c:240
 init_sb+0x9d4/0x12f0 fs/gfs2/ops_fstype.c:490
 gfs2_fill_super+0x1739/0x21d0 fs/gfs2/ops_fstype.c:1225
 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694
 gfs2_get_tree+0x51/0x1e0 fs/gfs2/ops_fstype.c:1342
 vfs_get_tree+0x92/0x2a0 fs/super.c:1754
 fc_mount fs/namespace.c:1193 [inline]
 do_new_mount_fc fs/namespace.c:3764 [inline]
 do_new_mount+0x341/0xd30 fs/namespace.c:3840
 do_mount fs/namespace.c:4173 [inline]
 __do_sys_mount fs/namespace.c:4372 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4349
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88807e71e780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88807e71e800: fc fc fc fc fc fc fc fc fc fc fa fb fb fb fb fb
>ffff88807e71e880: fb fb fb fb fc fc fc fc fa fb fb fb fb fb fb fb
                                                    ^
 ffff88807e71e900: fb fb fc fc fc fc fa fb fb fb fb fb fb fb fb fb
 ffff88807e71e980: fc fc fc fc fa fb fb fb fb fb fb fb fb fb fc fc
==================================================================


Tested on:

commit:         85964cdc Add linux-next specific files for 20260324
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=126f0c26580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=84ab18c6f45b39c
dashboard link: https://syzkaller.appspot.com/bug?extid=9013411dc43f3582823a
compiler:       Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
patch:          https://syzkaller.appspot.com/x/patch.diff?x=14bbc4ca580000

Re: [syzbot] [gfs2?] INFO: task hung in gfs2_recover_journal (4)

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-use-after-free Read in gfs2_invalidate_folio

RBP: 00007ffde9a1cf60 R08: 00007ffde9a1df60 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffde9a1dff0
R13: 00007fe90d032050 R14: 000000000001f130 R15: 00007ffde9a1e030
 </TASK>
gfs2: fsid=syz:syz.0: gfs2_evict_inode: -5
==================================================================
BUG: KASAN: slab-use-after-free in list_empty include/linux/list.h:381 [inline]
BUG: KASAN: slab-use-after-free in gfs2_discard fs/gfs2/aops.c:590 [inline]
BUG: KASAN: slab-use-after-free in gfs2_invalidate_folio+0x40b/0x750 fs/gfs2/aops.c:628
Read of size 8 at addr ffff88807c9098d8 by task syz-executor/6336

CPU: 0 UID: 0 PID: 6336 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 list_empty include/linux/list.h:381 [inline]
 gfs2_discard fs/gfs2/aops.c:590 [inline]
 gfs2_invalidate_folio+0x40b/0x750 fs/gfs2/aops.c:628
 folio_invalidate mm/truncate.c:140 [inline]
 truncate_cleanup_folio+0xcb/0x190 mm/truncate.c:160
 truncate_inode_pages_range+0x2ce/0xe30 mm/truncate.c:404
 gfs2_evict_inode+0x9da/0x12d0 fs/gfs2/super.c:1476
 evict+0x61e/0xb10 fs/inode.c:846
 gfs2_put_super+0x355/0x890 fs/gfs2/super.c:619
 generic_shutdown_super+0x13d/0x2d0 fs/super.c:646
 kill_block_super+0x44/0x90 fs/super.c:1725
 deactivate_locked_super+0xbc/0x130 fs/super.c:476
 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
 exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
 do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe90cf9d9d7
Code: a2 c7 05 1c fd 24 00 00 00 00 00 eb 96 e8 e1 12 00 00 90 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffde9a1cea8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fe90d032050 RCX: 00007fe90cf9d9d7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffde9a1cf60
RBP: 00007ffde9a1cf60 R08: 00007ffde9a1df60 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffde9a1dff0
R13: 00007fe90d032050 R14: 000000000001f130 R15: 00007ffde9a1e030
 </TASK>

Allocated by task 6336:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 unpoison_slab_object mm/kasan/common.c:340 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4569 [inline]
 slab_alloc_node mm/slub.c:4898 [inline]
 kmem_cache_alloc_noprof+0x2bc/0x650 mm/slub.c:4905
 gfs2_alloc_bufdata fs/gfs2/trans.c:176 [inline]
 gfs2_trans_add_data+0x1e8/0x610 fs/gfs2/trans.c:215
 gfs2_unstuffer_folio fs/gfs2/bmap.c:81 [inline]
 __gfs2_unstuff_inode fs/gfs2/bmap.c:119 [inline]
 gfs2_unstuff_dinode+0xace/0x1240 fs/gfs2/bmap.c:166
 gfs2_adjust_quota+0x23f/0x850 fs/gfs2/quota.c:848
 do_sync+0x872/0xcb0 fs/gfs2/quota.c:962
 gfs2_quota_sync+0x370/0x470 fs/gfs2/quota.c:1358
 gfs2_sync_fs+0x4c/0xb0 fs/gfs2/super.c:661
 sync_filesystem+0xee/0x230 fs/sync.c:56
 generic_shutdown_super+0x77/0x2d0 fs/super.c:625
 kill_block_super+0x44/0x90 fs/super.c:1725
 deactivate_locked_super+0xbc/0x130 fs/super.c:476
 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
 exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
 do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 6336:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2689 [inline]
 slab_free mm/slub.c:6242 [inline]
 kmem_cache_free+0x182/0x650 mm/slub.c:6369
 gfs2_trans_drain_list fs/gfs2/log.c:995 [inline]
 gfs2_trans_drain fs/gfs2/log.c:1013 [inline]
 gfs2_log_flush+0x18c1/0x2640 fs/gfs2/log.c:1185
 do_sync+0xa48/0xcb0 fs/gfs2/quota.c:982
 gfs2_quota_sync+0x370/0x470 fs/gfs2/quota.c:1358
 gfs2_sync_fs+0x4c/0xb0 fs/gfs2/super.c:661
 sync_filesystem+0xee/0x230 fs/sync.c:56
 generic_shutdown_super+0x77/0x2d0 fs/super.c:625
 kill_block_super+0x44/0x90 fs/super.c:1725
 deactivate_locked_super+0xbc/0x130 fs/super.c:476
 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
 exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
 do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88807c9098c0
 which belongs to the cache gfs2-bufdata/syz:syz of size 80
The buggy address is located 24 bytes inside of
 freed 80-byte region [ffff88807c9098c0, ffff88807c909910)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88807c909a80 pfn:0x7c909
flags: 0xfff00000000200(workingset|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000200 ffff8881499c0500 ffff888035149d08 ffff888035149d08
raw: ffff88807c909a80 0000000800240018 00000000f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0xd2c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 6336, tgid 6336 (syz-executor), ts 127950955156, free_ts 125551511102
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x231/0x280 mm/page_alloc.c:1859
 prep_new_page mm/page_alloc.c:1867 [inline]
 get_page_from_freelist+0x2418/0x24b0 mm/page_alloc.c:3926
 __alloc_frozen_pages_noprof+0x233/0x3d0 mm/page_alloc.c:5213
 alloc_slab_page mm/slub.c:3278 [inline]
 allocate_slab+0x77/0x660 mm/slub.c:3467
 new_slab mm/slub.c:3525 [inline]
 refill_objects+0x339/0x3d0 mm/slub.c:7247
 refill_sheaf mm/slub.c:2816 [inline]
 __pcs_replace_empty_main+0x321/0x720 mm/slub.c:4651
 alloc_from_pcs mm/slub.c:4749 [inline]
 slab_alloc_node mm/slub.c:4883 [inline]
 kmem_cache_alloc_noprof+0x37d/0x650 mm/slub.c:4905
 gfs2_alloc_bufdata fs/gfs2/trans.c:176 [inline]
 gfs2_trans_add_meta+0x214/0x8e0 fs/gfs2/trans.c:279
 gfs2_alloc_extent fs/gfs2/rgrp.c:2237 [inline]
 gfs2_alloc_blocks+0x7ae/0x2090 fs/gfs2/rgrp.c:2447
 __gfs2_unstuff_inode fs/gfs2/bmap.c:107 [inline]
 gfs2_unstuff_dinode+0x249/0x1240 fs/gfs2/bmap.c:166
 gfs2_adjust_quota+0x23f/0x850 fs/gfs2/quota.c:848
 do_sync+0x872/0xcb0 fs/gfs2/quota.c:962
 gfs2_quota_sync+0x370/0x470 fs/gfs2/quota.c:1358
 gfs2_sync_fs+0x4c/0xb0 fs/gfs2/super.c:661
 sync_filesystem+0xee/0x230 fs/sync.c:56
 generic_shutdown_super+0x77/0x2d0 fs/super.c:625
page last free pid 23 tgid 23 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1403 [inline]
 __free_frozen_pages+0xbc7/0xd30 mm/page_alloc.c:2944
 __tlb_remove_table_free mm/mmu_gather.c:228 [inline]
 tlb_remove_table_rcu+0x85/0x100 mm/mmu_gather.c:291
 rcu_do_batch kernel/rcu/tree.c:2617 [inline]
 rcu_core+0x7cd/0x1070 kernel/rcu/tree.c:2869
 handle_softirqs+0x22a/0x840 kernel/softirq.c:622
 run_ksoftirqd+0x36/0x60 kernel/softirq.c:1076
 smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Memory state around the buggy address:
 ffff88807c909780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88807c909800: fc fc fc fc fc fc fc fc fc fc fa fb fb fb fb fb
>ffff88807c909880: fb fb fb fb fc fc fc fc fa fb fb fb fb fb fb fb
                                                    ^
 ffff88807c909900: fb fb fc fc fc fc fa fb fb fb fb fb fb fb fb fb
 ffff88807c909980: fc fc fc fc fa fb fb fb fb fb fb fb fb fb fc fc
==================================================================


Tested on:

commit:         85964cdc Add linux-next specific files for 20260324
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=14e9506a580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=84ab18c6f45b39c
dashboard link: https://syzkaller.appspot.com/bug?extid=9013411dc43f3582823a
compiler:       Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
patch:          https://syzkaller.appspot.com/x/patch.diff?x=11b46a06580000

Re: [syzbot] [gfs2?] INFO: task hung in gfs2_recover_journal (4)

[Edward Adam Davis]

#syz test

diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index 1cd8ec0bce83..fd11d5aa93b6 100644
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -2266,6 +2266,9 @@ int gfs2_map_journal_extents(struct gfs2_sbd *sdp, struct gfs2_jdesc *jd)
 	u64 size;
 	int rc;
 	ktime_t start, end;
+	struct super_block *sb = sdp->sd_vfs;
+	sector_t maxsector = bdev_nr_sectors(sb->s_bdev);
+	u32 bshift = sdp->sd_fsb2bb_shift;
 
 	start = ktime_get();
 	lblock_stop = i_size_read(jd->jd_inode) >> shift;
@@ -2280,6 +2283,10 @@ int gfs2_map_journal_extents(struct gfs2_sbd *sdp, struct gfs2_jdesc *jd)
 		rc = gfs2_block_map(jd->jd_inode, lblock, &bh, 0);
 		if (rc || !buffer_mapped(&bh))
 			goto fail;
+		if (bh.b_blocknr << bshift > maxsector) {
+			rc = -EIO;
+			goto fail;
+		}
 		rc = gfs2_add_jextent(jd, lblock, bh.b_blocknr, bh.b_size >> shift);
 		if (rc)
 			goto fail;

Re: [syzbot] [gfs2?] INFO: task hung in gfs2_recover_journal (4)

[Edward Adam Davis]

#syz test

diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index 1cd8ec0bce83..fd11d5aa93b6 100644
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -2266,6 +2266,9 @@ int gfs2_map_journal_extents(struct gfs2_sbd *sdp, struct gfs2_jdesc *jd)
 	u64 size;
 	int rc;
 	ktime_t start, end;
+	struct super_block *sb = sdp->sd_vfs;
+	sector_t maxsector = bdev_nr_sectors(sb->s_bdev);
+	u32 bshift = sdp->sd_fsb2bb_shift;
 
 	start = ktime_get();
 	lblock_stop = i_size_read(jd->jd_inode) >> shift;
@@ -2280,6 +2283,10 @@ int gfs2_map_journal_extents(struct gfs2_sbd *sdp, struct gfs2_jdesc *jd)
 		rc = gfs2_block_map(jd->jd_inode, lblock, &bh, 0);
 		if (rc || !buffer_mapped(&bh))
 			goto fail;
+		if (bh.b_blocknr << bshift > maxsector) {
+			rc = -EIO;
+			goto fail;
+		}
 		rc = gfs2_add_jextent(jd, lblock, bh.b_blocknr, bh.b_size >> shift);
 		if (rc)
 			goto fail;

Re: [syzbot] [gfs2?] INFO: task hung in gfs2_recover_journal (4)

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
WARNING in gfs2_fill_super

loop1: detected capacity change from 0 to 32768
------------[ cut here ]------------
kmem_cache of name 'gfs2-bufdata/syz:syz' already exists
WARNING: mm/slab_common.c:112 at kmem_cache_sanity_check mm/slab_common.c:111 [inline], CPU#0: syz.1.21/6483
WARNING: mm/slab_common.c:112 at __kmem_cache_create_args+0xac/0x440 mm/slab_common.c:352, CPU#0: syz.1.21/6483
Modules linked in:
CPU: 0 UID: 0 PID: 6483 Comm: syz.1.21 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:kmem_cache_sanity_check mm/slab_common.c:111 [inline]
RIP: 0010:__kmem_cache_create_args+0xaf/0x440 mm/slab_common.c:352
Code: 86 8e 4d 8b 24 24 49 81 fc 18 68 86 8e 74 20 49 8b 7c 24 f8 48 89 de e8 3f 5c 9c 09 85 c0 75 e2 48 8d 3d 54 70 06 0e 48 89 de <67> 48 0f b9 3a 48 89 df be 20 00 00 00 e8 df 5d 9c 09 48 85 c0 0f
RSP: 0018:ffffc90003477948 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff888026fe5f80 RCX: 0000000000000005
RDX: 0000000026fe5f04 RSI: ffff888026fe5f80 RDI: ffffffff9016e0b0
RBP: 0000000000000000 R08: ffffffff901246f7 R09: 1ffffffff20248de
R10: dffffc0000000000 R11: fffffbfff20248df R12: ffff888027604ba0
R13: ffff888078654000 R14: 0000000000000050 R15: ffffc90003477a60
FS:  00007fe28ae0f6c0(0000) GS:ffff888125448000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe289f85900 CR3: 0000000026234000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __kmem_cache_create include/linux/slab.h:390 [inline]
 gfs2_fill_super+0x13a4/0x21d0 fs/gfs2/ops_fstype.c:1202
 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694
 gfs2_get_tree+0x51/0x1e0 fs/gfs2/ops_fstype.c:1342
 vfs_get_tree+0x92/0x2a0 fs/super.c:1754
 fc_mount fs/namespace.c:1193 [inline]
 do_new_mount_fc fs/namespace.c:3764 [inline]
 do_new_mount+0x341/0xd30 fs/namespace.c:3840
 do_mount fs/namespace.c:4173 [inline]
 __do_sys_mount fs/namespace.c:4372 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4349
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe289f9da0a
Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe28ae0ee58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fe28ae0eee0 RCX: 00007fe289f9da0a
RDX: 0000200000037f40 RSI: 0000200000037f80 RDI: 00007fe28ae0eea0
RBP: 0000200000037f40 R08: 00007fe28ae0eee0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000037f80
R13: 00007fe28ae0eea0 R14: 0000000000037fc4 R15: 0000200000000300
 </TASK>
----------------
Code disassembly (best guess):
   0:	86 8e 4d 8b 24 24    	xchg   %cl,0x24248b4d(%rsi)
   6:	49 81 fc 18 68 86 8e 	cmp    $0xffffffff8e866818,%r12
   d:	74 20                	je     0x2f
   f:	49 8b 7c 24 f8       	mov    -0x8(%r12),%rdi
  14:	48 89 de             	mov    %rbx,%rsi
  17:	e8 3f 5c 9c 09       	call   0x99c5c5b
  1c:	85 c0                	test   %eax,%eax
  1e:	75 e2                	jne    0x2
  20:	48 8d 3d 54 70 06 0e 	lea    0xe067054(%rip),%rdi        # 0xe06707b
  27:	48 89 de             	mov    %rbx,%rsi
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	48 89 df             	mov    %rbx,%rdi
  32:	be 20 00 00 00       	mov    $0x20,%esi
  37:	e8 df 5d 9c 09       	call   0x99c5e1b
  3c:	48 85 c0             	test   %rax,%rax
  3f:	0f                   	.byte 0xf


Tested on:

commit:         09c0f7f1 Add linux-next specific files for 20260323
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=16b46ada580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c0c30527ccbcb0f2
dashboard link: https://syzkaller.appspot.com/bug?extid=9013411dc43f3582823a
compiler:       Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
patch:          https://syzkaller.appspot.com/x/patch.diff?x=146f906a580000

Re: [syzbot] [gfs2?] INFO: task hung in gfs2_recover_journal (4)

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
WARNING in gfs2_fill_super

loop1: detected capacity change from 0 to 32768
------------[ cut here ]------------
kmem_cache of name 'gfs2-bufdata/syz:syz' already exists
WARNING: mm/slab_common.c:112 at kmem_cache_sanity_check mm/slab_common.c:111 [inline], CPU#1: syz.1.18/6629
WARNING: mm/slab_common.c:112 at __kmem_cache_create_args+0xac/0x440 mm/slab_common.c:352, CPU#1: syz.1.18/6629
Modules linked in:
CPU: 1 UID: 0 PID: 6629 Comm: syz.1.18 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:kmem_cache_sanity_check mm/slab_common.c:111 [inline]
RIP: 0010:__kmem_cache_create_args+0xaf/0x440 mm/slab_common.c:352
Code: 86 8e 4d 8b 24 24 49 81 fc 18 68 86 8e 74 20 49 8b 7c 24 f8 48 89 de e8 3f 5c 9c 09 85 c0 75 e2 48 8d 3d 54 70 06 0e 48 89 de <67> 48 0f b9 3a 48 89 df be 20 00 00 00 e8 df 5d 9c 09 48 85 c0 0f
RSP: 0018:ffffc90002587948 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff88805dca3500 RCX: 0000000000000005
RDX: 000000005dca3504 RSI: ffff88805dca3500 RDI: ffffffff9016e0b0
RBP: 0000000000000000 R08: ffffffff901246f7 R09: 1ffffffff20248de
R10: dffffc0000000000 R11: fffffbfff20248df R12: ffff888035c9b920
R13: ffff88807cdf8000 R14: 0000000000000050 R15: ffffc90002587a60
FS:  00007f0e2aa0a6c0(0000) GS:ffff888125548000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fffebd18738 CR3: 000000007944c000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __kmem_cache_create include/linux/slab.h:390 [inline]
 gfs2_fill_super+0x13a4/0x21d0 fs/gfs2/ops_fstype.c:1202
 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694
 gfs2_get_tree+0x51/0x1e0 fs/gfs2/ops_fstype.c:1342
 vfs_get_tree+0x92/0x2a0 fs/super.c:1754
 fc_mount fs/namespace.c:1193 [inline]
 do_new_mount_fc fs/namespace.c:3764 [inline]
 do_new_mount+0x341/0xd30 fs/namespace.c:3840
 do_mount fs/namespace.c:4173 [inline]
 __do_sys_mount fs/namespace.c:4372 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4349
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0e29b9da0a
Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f0e2aa09e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f0e2aa09ee0 RCX: 00007f0e29b9da0a
RDX: 0000200000037f40 RSI: 0000200000037f80 RDI: 00007f0e2aa09ea0
RBP: 0000200000037f40 R08: 00007f0e2aa09ee0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000037f80
R13: 00007f0e2aa09ea0 R14: 0000000000037fc4 R15: 0000200000000300
 </TASK>
----------------
Code disassembly (best guess):
   0:	86 8e 4d 8b 24 24    	xchg   %cl,0x24248b4d(%rsi)
   6:	49 81 fc 18 68 86 8e 	cmp    $0xffffffff8e866818,%r12
   d:	74 20                	je     0x2f
   f:	49 8b 7c 24 f8       	mov    -0x8(%r12),%rdi
  14:	48 89 de             	mov    %rbx,%rsi
  17:	e8 3f 5c 9c 09       	call   0x99c5c5b
  1c:	85 c0                	test   %eax,%eax
  1e:	75 e2                	jne    0x2
  20:	48 8d 3d 54 70 06 0e 	lea    0xe067054(%rip),%rdi        # 0xe06707b
  27:	48 89 de             	mov    %rbx,%rsi
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	48 89 df             	mov    %rbx,%rdi
  32:	be 20 00 00 00       	mov    $0x20,%esi
  37:	e8 df 5d 9c 09       	call   0x99c5e1b
  3c:	48 85 c0             	test   %rax,%rax
  3f:	0f                   	.byte 0xf


Tested on:

commit:         09c0f7f1 Add linux-next specific files for 20260323
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=13a59e16580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c0c30527ccbcb0f2
dashboard link: https://syzkaller.appspot.com/bug?extid=9013411dc43f3582823a
compiler:       Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
patch:          https://syzkaller.appspot.com/x/patch.diff?x=11d9c1d6580000

[syzbot] [gfs2?] INFO: task hung in gfs2_recover_journal (4)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    785f0eb2f85d Add linux-next specific files for 20260320
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=11b352f6580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c584910d0d74158d
dashboard link: https://syzkaller.appspot.com/bug?extid=9013411dc43f3582823a
compiler:       Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=15b352f6580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1528aada580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/a1f7fd9c1a63/disk-785f0eb2.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/6c138da87c25/vmlinux-785f0eb2.xz
kernel image: https://storage.googleapis.com/syzbot-assets/4d1be64e56db/bzImage-785f0eb2.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/b8d9a874b489/mount_0.gz
  fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=16fc7ada580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9013411dc43f3582823a@syzkaller.appspotmail.com

INFO: task kworker/0:3:5963 blocked in I/O wait for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:3     state:D stack:25400 pid:5963  tgid:5963  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: gfs2_recovery gfs2_recover_func
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5352 [inline]
 __schedule+0x165c/0x5560 kernel/sched/core.c:6964
 __schedule_loop kernel/sched/core.c:7047 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7062
 io_schedule+0x7f/0xd0 kernel/sched/core.c:7889
 folio_wait_bit_common+0x6d8/0xbc0 mm/filemap.c:1324
 folio_wait_locked include/linux/pagemap.h:1245 [inline]
 gfs2_jhead_process_page+0x175/0x670 fs/gfs2/lops.c:470
 gfs2_find_jhead+0xbd2/0xd30 fs/gfs2/lops.c:586
 gfs2_recover_func+0x6cf/0x1f60 fs/gfs2/recovery.c:459
 process_one_work+0x9a3/0x1710 kernel/workqueue.c:3288
 process_scheduled_works kernel/workqueue.c:3379 [inline]
 worker_thread+0xba8/0x11e0 kernel/workqueue.c:3465
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
INFO: task syz.0.18:6005 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.18        state:D stack:24120 pid:6005  tgid:6005  ppid:5953   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5352 [inline]
 __schedule+0x165c/0x5560 kernel/sched/core.c:6964
 __schedule_loop kernel/sched/core.c:7047 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7062
 bit_wait+0x11/0xd0 kernel/sched/wait_bit.c:240
 __wait_on_bit+0xb9/0x310 kernel/sched/wait_bit.c:52
 out_of_line_wait_on_bit+0x13b/0x190 kernel/sched/wait_bit.c:67
 wait_on_bit include/linux/wait_bit.h:77 [inline]
 gfs2_recover_journal+0xda/0x140 fs/gfs2/recovery.c:579
 init_journal+0x16ad/0x2280 fs/gfs2/ops_fstype.c:794
 init_inodes+0xdb/0x320 fs/gfs2/ops_fstype.c:844
 gfs2_fill_super+0x1a38/0x21d0 fs/gfs2/ops_fstype.c:1250
 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694
 gfs2_get_tree+0x51/0x1e0 fs/gfs2/ops_fstype.c:1332
 vfs_get_tree+0x92/0x2a0 fs/super.c:1754
 fc_mount fs/namespace.c:1193 [inline]
 do_new_mount_fc fs/namespace.c:3764 [inline]
 do_new_mount+0x341/0xd30 fs/namespace.c:3840
 do_mount fs/namespace.c:4173 [inline]
 __do_sys_mount fs/namespace.c:4372 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4349
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f611259da0a
RSP: 002b:00007ffe1764d4e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffe1764d570 RCX: 00007f611259da0a
RDX: 0000200000037f40 RSI: 0000200000037f80 RDI: 00007ffe1764d530
RBP: 0000200000037f40 R08: 00007ffe1764d570 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000037f80
R13: 00007ffe1764d530 R14: 0000000000037fc4 R15: 0000200000000300
 </TASK>

Showing all locks held in the system:
1 lock held by pool_workqueue_/3:
1 lock held by khungtaskd/30:
 #0: ffffffff8e75d7e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
 #0: ffffffff8e75d7e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
 #0: ffffffff8e75d7e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5600:
 #0: ffff888037d8f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211
2 locks held by kworker/0:3/5963:
 #0: ffff8880232a6140 ((wq_completion)gfs2_recovery){+.+.}-{0:0}, at: process_one_work+0x890/0x1710 kernel/workqueue.c:3260
 #1: ffffc900043b7c40 ((work_completion)(&jd->jd_work)){+.+.}-{0:0}, at: process_one_work+0x8b7/0x1710 kernel/workqueue.c:3261
1 lock held by syz.0.18/6005:
 #0: ffff8880346ce0d8 (&type->s_umount_key#54/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xab0 fs/super.c:345
3 locks held by syz.1.203/6599:

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x135/0x170 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
 watchdog+0xfd3/0x1030 kernel/hung_task.c:561
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 6599 Comm: syz.1.203 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:mark_lock+0xa4/0x190 kernel/locking/lockdep.c:4774
Code: 0e 48 c7 c6 19 03 06 8e 67 48 0f b9 3a 90 31 c9 4c 89 fe 4c 89 f7 b8 01 00 00 00 85 69 60 74 10 5b 41 5c 41 5d 41 5e 41 5f 5d <c3> cc cc cc cc cc 49 89 fe 49 89 f7 e8 5b 94 ff ff 89 c1 31 c0 85
RSP: 0018:ffffc90000a08840 EFLAGS: 00000006
RAX: 0000000000000001 RBX: ffff88801d3dc8e8 RCX: ffffffff93c65330
RDX: 0000000000000008 RSI: ffff88801d3dc8c8 RDI: ffff88801d3dbd00
RBP: ffff88801d3dc8c8 R08: ffffffff84b9d570 R09: ffffffff9a4fdcb8
R10: ffffc90000a08a60 R11: fffff5200014114e R12: 0000000000000003
R13: ffff88801d3dc8c8 R14: ffff88801d3dbd00 R15: 0000000000000003
FS:  000055557c000500(0000) GS:ffff888125548000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055910e737168 CR3: 000000006c700000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 mark_usage kernel/locking/lockdep.c:4674 [inline]
 __lock_acquire+0x6b5/0x2cf0 kernel/locking/lockdep.c:5191
 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline]
 _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:166
 debug_object_assert_init+0xb0/0x370 lib/debugobjects.c:1035
 debug_timer_assert_init kernel/time/timer.c:803 [inline]
 debug_assert_init kernel/time/timer.c:848 [inline]
 __mod_timer+0x4a/0xf30 kernel/time/timer.c:1025
 dsp_cmx_send+0x1abe/0x1b40 drivers/isdn/mISDN/dsp_cmx.c:1839
 call_timer_fn+0x192/0x5e0 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers kernel/time/timer.c:2373 [inline]
 __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2385
 run_timer_base kernel/time/timer.c:2394 [inline]
 run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2404
 handle_softirqs+0x22a/0x840 kernel/softirq.c:626
 __do_softirq kernel/softirq.c:660 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xca/0x220 kernel/softirq.c:739
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:756
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2039 [inline]
RIP: 0010:vprintk_emit+0x45d/0x560 kernel/printk/printk.c:2478
Code: 0f 84 44 ff ff ff e8 a2 09 21 00 fb eb 44 e8 9a 09 21 00 e8 75 7b 0b 0a 4d 85 f6 74 94 e8 8b 09 21 00 fb 48 c7 c7 00 fc 74 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 cb 18
RSP: 0018:ffffc90004b06e00 EFLAGS: 00000293
RAX: ffffffff81a547f5 RBX: ffffffff81a5466f RCX: ffff88801d3dbd00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e74fc00
RBP: ffffc90004b06eb0 R08: ffffffff90123cf7 R09: 1ffffffff202479e
R10: dffffc0000000000 R11: fffffbfff202479f R12: 0000000000000000
R13: 000000000000002f R14: 0000000000000200 R15: 1ffff92000960dc4
 _printk+0xdd/0x130 kernel/printk/printk.c:2504
 set_capacity_and_notify+0x2c5/0x320 block/genhd.c:93
 loop_set_size+0x44/0xb0 drivers/block/loop.c:220
 loop_configure+0x9ac/0xdf0 drivers/block/loop.c:1079
 lo_ioctl+0x447/0x1fb0 drivers/block/loop.c:1534
 blkdev_ioctl+0x5e3/0x740 block/ioctl.c:804
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa17279c42b
Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00
RSP: 002b:00007ffde9d10a80 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007fa17279c42b
RDX: 0000000000000003 RSI: 0000000000004c00 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 00007ffde9d10bb0 R14: 00007ffde9d10b70 R15: 00007fa169800000
 </TASK>


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup