KASAN: use-after-free Read in xfs_inode_item_push (2)

Status: upstream: reported C repro on 2025/01/31 01:44
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+ac6e2c95a764b3e2d045@syzkaller.appspotmail.com
First crash: 568d, last: 441d
Fix bisection: the issue occurs on the latest tested release (bisect log)
Crash: KASAN: use-after-free Read in xfs_iflush_cluster (log)
Repro: C syz .config
  
▶ ▼ Bug presence (2)
Date Name Commit Repro Result
2025/03/24 linux-5.15.y (ToT) 0c935c049b5c C [report] KASAN: use-after-free Read in xfs_iflush_cluster
2025/03/24 upstream (ToT) 586de92313fc C Didn't crash
▶ ▼ Similar bugs (8)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 KASAN: use-after-free Read in xfs_inode_item_push (2) 19 1 716d 716d 0/3 auto-obsoleted due to no activity on 2024/12/14 11:37
upstream KASAN: use-after-free Read in xfs_inode_item_push xfs 19 16 1063d 1289d 0/29 auto-obsoleted due to no activity on 2024/01/02 00:00
linux-6.1 KASAN: use-after-free Read in xfs_inode_item_push 19 1 1211d 1211d 0/3 auto-obsoleted due to no activity on 2023/08/23 09:03
linux-5.15 KASAN: use-after-free Read in xfs_inode_item_push 19 2 1190d 1193d 0/3 auto-obsoleted due to no activity on 2023/08/28 08:02
linux-6.1 KASAN: use-after-free Read in xfs_inode_item_push (3) 19 1 212d 212d 0/3 auto-obsoleted due to no activity on 2026/05/02 12:51
upstream KASAN: slab-use-after-free Read in xfs_inode_item_push xfs 19 syz, C error 430 149d 864d 0/29 auto-obsoleted due to no activity on 2026/06/19 13:32
linux-6.6 KFENCE: use-after-free read in xfs_inode_item_push 19 2 314d 321d 0/2 auto-obsoleted due to no activity on 2026/01/20 14:10
linux-6.6 KASAN: slab-use-after-free Read in xfs_inode_item_push 19 1 207d 207d 2/2 fixed on 2026/04/06 08:33
▶ ▼ Last patch testing requests (8)
Created Duration User Patch Repo Result
2026/08/19 00:48 23m retest repro linux-5.15.y report job log log
2026/05/29 22:27 22m retest repro linux-5.15.y report log
2026/03/18 05:41 14m retest repro linux-5.15.y report log
2026/03/18 05:33 12m retest repro linux-5.15.y report log
2026/01/06 17:37 12m retest repro linux-5.15.y report log
2025/10/27 16:42 17m retest repro linux-5.15.y report log
2025/08/18 01:28 55m retest repro linux-5.15.y report log
2025/03/23 01:38 18m retest repro linux-5.15.y report log
▶ ▼ Fix bisection attempts (4)
Created Duration User Patch Repo Result
2025/07/02 05:43 3h46m fix candidate upstream OK (0) job log
2025/06/07 09:06 2h22m bisect fix linux-5.15.y OK (0) job log log
2025/05/07 11:12 2h16m bisect fix linux-5.15.y OK (0) job log log
2025/04/06 09:20 2h02m bisect fix linux-5.15.y OK (0) job log log

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in xfs_inode_item_push+0x25e/0x2c0 fs/xfs/xfs_inode_item.c:582
Read of size 8 at addr ffff88806fd1bdf0 by task xfsaild/loop2/6545

CPU: 1 PID: 6545 Comm: xfsaild/loop2 Not tainted 5.15.178-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 print_address_description+0x63/0x3b0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0x16b/0x1c0 mm/kasan/report.c:451
 xfs_inode_item_push+0x25e/0x2c0 fs/xfs/xfs_inode_item.c:582
 xfsaild_push_item fs/xfs/xfs_trans_ail.c:414 [inline]
 xfsaild_push fs/xfs/xfs_trans_ail.c:472 [inline]
 xfsaild+0xd6d/0x2970 fs/xfs/xfs_trans_ail.c:657
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>

Allocated by task 6520:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 __kasan_slab_alloc+0x8e/0xc0 mm/kasan/common.c:467
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x53/0x380 mm/slab.h:519
 slab_alloc_node mm/slub.c:3220 [inline]
 slab_alloc mm/slub.c:3228 [inline]
 kmem_cache_alloc+0xf3/0x280 mm/slub.c:3233
 kmem_cache_zalloc include/linux/slab.h:711 [inline]
 xfs_inode_item_init+0x2f/0xc0 fs/xfs/xfs_inode_item.c:675
 xfs_trans_ijoin+0xb6/0xe0 fs/xfs/libxfs/xfs_trans_inode.c:36
 xfs_init_new_inode+0xd8c/0x1100 fs/xfs/xfs_inode.c:918
 xfs_qm_qino_alloc+0x516/0x9c0 fs/xfs/xfs_qm.c:790
 xfs_qm_init_quotainos+0x657/0x8a0 fs/xfs/xfs_qm.c:1559
 xfs_qm_init_quotainfo+0xa6/0x970 fs/xfs/xfs_qm.c:644
 xfs_qm_mount_quotas+0x90/0x610 fs/xfs/xfs_qm.c:1435
 xfs_mountfs+0x166a/0x1ce0 fs/xfs/xfs_mount.c:904
 xfs_fs_fill_super+0x11b4/0x1400 fs/xfs/xfs_super.c:1676
 get_tree_bdev+0x3fe/0x620 fs/super.c:1325
 vfs_get_tree+0x88/0x270 fs/super.c:1530
 do_new_mount+0x2ba/0xb40 fs/namespace.c:3012
 do_mount fs/namespace.c:3355 [inline]
 __do_sys_mount fs/namespace.c:3563 [inline]
 __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3540
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Freed by task 6546:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4b/0x80 mm/kasan/common.c:46
 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
 ____kasan_slab_free+0xd8/0x120 mm/kasan/common.c:366
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1705 [inline]
 slab_free_freelist_hook+0xdd/0x160 mm/slub.c:1731
 slab_free mm/slub.c:3499 [inline]
 kmem_cache_free+0x91/0x1f0 mm/slub.c:3515
 xfs_inode_free_callback+0x1bd/0x230 fs/xfs/xfs_icache.c:142
 rcu_do_batch kernel/rcu/tree.c:2523 [inline]
 rcu_core+0xa15/0x1650 kernel/rcu/tree.c:2763
 handle_softirqs+0x3a7/0x930 kernel/softirq.c:558
 __do_softirq kernel/softirq.c:592 [inline]
 invoke_softirq kernel/softirq.c:432 [inline]
 __irq_exit_rcu+0x157/0x240 kernel/softirq.c:641
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:653
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676

The buggy address belongs to the object at ffff88806fd1bdc0
 which belongs to the cache xfs_ili of size 256
The buggy address is located 48 bytes inside of
 256-byte region [ffff88806fd1bdc0, ffff88806fd1bec0)
The buggy address belongs to the page:
page:ffffea0001bf46c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x6fd1b
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffffea0000ae2040 0000000800000008 ffff888146a3c780
raw: 0000000000000000 00000000000c000c 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Reclaimable, gfp_mask 0x12c50(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY|__GFP_RECLAIMABLE), pid 4165, ts 60583424245, free_ts 19117954616
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x3b78/0x3d40 mm/page_alloc.c:4192
 __alloc_pages+0x272/0x700 mm/page_alloc.c:5465
 alloc_slab_page mm/slub.c:1775 [inline]
 allocate_slab mm/slub.c:1912 [inline]
 new_slab+0xbb/0x4b0 mm/slub.c:1975
 ___slab_alloc+0x6f6/0xe10 mm/slub.c:3008
 __slab_alloc mm/slub.c:3095 [inline]
 slab_alloc_node mm/slub.c:3186 [inline]
 slab_alloc mm/slub.c:3228 [inline]
 kmem_cache_alloc+0x18e/0x280 mm/slub.c:3233
 kmem_cache_zalloc include/linux/slab.h:711 [inline]
 xfs_inode_item_init+0x2f/0xc0 fs/xfs/xfs_inode_item.c:675
 xfs_trans_ijoin+0xb6/0xe0 fs/xfs/libxfs/xfs_trans_inode.c:36
 xfs_trans_alloc_dir+0x227/0x700 fs/xfs/xfs_trans.c:1246
 xfs_remove+0x3e5/0xc20 fs/xfs/xfs_inode.c:2789
 xfs_vn_unlink+0x14d/0x2a0 fs/xfs/xfs_iops.c:387
 vfs_unlink+0x359/0x5f0 fs/namei.c:4280
 do_unlinkat+0x4a3/0x950 fs/namei.c:4348
 __do_sys_unlink fs/namei.c:4396 [inline]
 __se_sys_unlink fs/namei.c:4394 [inline]
 __x64_sys_unlink+0x45/0x50 fs/namei.c:4394
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1340 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0xc34/0xcf0 mm/page_alloc.c:3317
 free_unref_page+0x95/0x2d0 mm/page_alloc.c:3396
 free_contig_range+0x95/0xf0 mm/page_alloc.c:9384
 destroy_args+0xfe/0x980 mm/debug_vm_pgtable.c:1018
 debug_vm_pgtable+0x40d/0x470 mm/debug_vm_pgtable.c:1331
 do_one_initcall+0x22b/0x7a0 init/main.c:1302
 do_initcall_level+0x157/0x210 init/main.c:1375
 do_initcalls+0x49/0x90 init/main.c:1391
 kernel_init_freeable+0x425/0x5c0 init/main.c:1615
 kernel_init+0x19/0x290 init/main.c:1506
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

Memory state around the buggy address:
 ffff88806fd1bc80: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88806fd1bd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88806fd1bd80: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
                                                             ^
 ffff88806fd1be00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88806fd1be80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/03/03 11:48 linux-5.15.y c16c81c81336 c3901742 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-5-15-kasan KASAN: use-after-free Read in xfs_inode_item_push
2025/01/31 01:43 linux-5.15.y 003148680b79 4c6ac32f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Read in xfs_inode_item_push
* Struck through repros no longer work on HEAD.