KASAN: slab-use-after-free Read in xlog_cil_push

Title	Replies (including bot)	Last reply
[syzbot] [xfs?] KASAN: slab-use-after-free Read in xlog_cil_push_work	0 (1)	2025/08/21 13:03

Kernel	Title	Rank 🛈	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	BUG: unable to handle kernel paging request in xlog_cil_push_work xfs	8				5	114d	114d	0/29	auto-obsoleted due to no activity on 2025/08/08 19:37
upstream	KASAN: slab-out-of-bounds Write in xlog_cil_push_work xfs	24				3	440d	447d	0/29	auto-obsoleted due to no activity on 2024/09/06 14:39

==================================================================
BUG: KASAN: slab-use-after-free in __list_del_entry_valid_or_report+0xb5/0x190 lib/list_debug.c:65
Read of size 8 at addr ffff88805f82f850 by task kworker/u8:5/1029

CPU: 1 UID: 0 PID: 1029 Comm: kworker/u8:5 Not tainted 6.17.0-rc1-next-20250814-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: xfs-cil/loop4 xlog_cil_push_work
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xca/0x240 mm/kasan/report.c:482
 kasan_report+0x118/0x150 mm/kasan/report.c:595
 __list_del_entry_valid_or_report+0xb5/0x190 lib/list_debug.c:65
 __list_del_entry_valid include/linux/list.h:124 [inline]
 __list_del_entry include/linux/list.h:215 [inline]
 list_del_init include/linux/list.h:287 [inline]
 xlog_cil_build_lv_chain fs/xfs/xfs_log_cil.c:1246 [inline]
 xlog_cil_push_work+0x11c0/0x2570 fs/xfs/xfs_log_cil.c:1374
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 3859:
 kasan_save_stack mm/kasan/common.c:56 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
 unpoison_slab_object mm/kasan/common.c:339 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:365
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4180 [inline]
 slab_alloc_node mm/slub.c:4229 [inline]
 kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4236
 xfs_buf_item_init+0x66/0x670 fs/xfs/xfs_buf_item.c:878
 _xfs_trans_bjoin+0x46/0x110 fs/xfs/xfs_trans_buf.c:75
 xfs_trans_read_buf_map+0x28f/0x8e0 fs/xfs/xfs_trans_buf.c:325
 xfs_trans_read_buf fs/xfs/xfs_trans.h:210 [inline]
 xfs_btree_read_buf_block+0x290/0x470 fs/xfs/libxfs/xfs_btree.c:1402
 xfs_btree_lookup_get_block+0x28d/0x500 fs/xfs/libxfs/xfs_btree.c:1907
 xfs_btree_lookup+0x4e1/0x1410 fs/xfs/libxfs/xfs_btree.c:2018
 xfs_alloc_lookup fs/xfs/libxfs/xfs_alloc.c:166 [inline]
 xfs_alloc_lookup_le fs/xfs/libxfs/xfs_alloc.c:212 [inline]
 xfs_free_ag_extent+0x25d/0x1760 fs/xfs/libxfs/xfs_alloc.c:2080
 __xfs_free_extent+0x2f1/0x470 fs/xfs/libxfs/xfs_alloc.c:4048
 xfs_extent_free_finish_item+0x28b/0x670 fs/xfs/xfs_extfree_item.c:555
 xfs_defer_finish_one+0x5c8/0xcf0 fs/xfs/libxfs/xfs_defer.c:595
 xfs_defer_finish_noroll+0x910/0x12d0 fs/xfs/libxfs/xfs_defer.c:707
 xfs_defer_finish+0x1c/0x180 fs/xfs/libxfs/xfs_defer.c:741
 xfs_bunmapi_range+0xc4/0x140 fs/xfs/libxfs/xfs_bmap.c:6178
 xfs_itruncate_extents_flags+0x306/0x990 fs/xfs/xfs_inode.c:1066
 xfs_itruncate_extents fs/xfs/xfs_inode.h:604 [inline]
 xfs_inactive_truncate+0x125/0x1b0 fs/xfs/xfs_inode.c:1168
 xfs_inactive+0x949/0xcd0 fs/xfs/xfs_inode.c:1454
 xfs_inodegc_inactivate fs/xfs/xfs_icache.c:1944 [inline]
 xfs_inodegc_worker+0x31b/0x7c0 fs/xfs/xfs_icache.c:1990
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Freed by task 10:
 kasan_save_stack mm/kasan/common.c:56 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
 __kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:587
 kasan_save_free_info mm/kasan/kasan.h:406 [inline]
 poison_slab_object mm/kasan/common.c:252 [inline]
 __kasan_slab_free+0x5b/0x80 mm/kasan/common.c:284
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2417 [inline]
 slab_free mm/slub.c:4680 [inline]
 kmem_cache_free+0x18f/0x400 mm/slub.c:4782
 __xfs_buf_ioend+0x29c/0x6f0 fs/xfs/xfs_buf.c:1202
 xfs_buf_iowait+0x167/0x480 fs/xfs/xfs_buf.c:1384
 _xfs_buf_read fs/xfs/xfs_buf.c:646 [inline]
 xfs_buf_read_map+0x335/0xa50 fs/xfs/xfs_buf.c:712
 xfs_trans_read_buf_map+0x1d7/0x8e0 fs/xfs/xfs_trans_buf.c:304
 xfs_trans_read_buf fs/xfs/xfs_trans.h:210 [inline]
 xfs_btree_read_buf_block+0x290/0x470 fs/xfs/libxfs/xfs_btree.c:1402
 xfs_btree_lookup_get_block+0x28d/0x500 fs/xfs/libxfs/xfs_btree.c:1907
 xfs_btree_lookup+0x4e1/0x1410 fs/xfs/libxfs/xfs_btree.c:2018
 xfs_alloc_lookup fs/xfs/libxfs/xfs_alloc.c:166 [inline]
 xfs_alloc_lookup_le fs/xfs/libxfs/xfs_alloc.c:212 [inline]
 xfs_free_ag_extent+0x25d/0x1760 fs/xfs/libxfs/xfs_alloc.c:2080
 __xfs_free_extent+0x2f1/0x470 fs/xfs/libxfs/xfs_alloc.c:4048
 xfs_extent_free_finish_item+0x28b/0x670 fs/xfs/xfs_extfree_item.c:555
 xfs_defer_finish_one+0x5c8/0xcf0 fs/xfs/libxfs/xfs_defer.c:595
 xfs_defer_finish_noroll+0x910/0x12d0 fs/xfs/libxfs/xfs_defer.c:707
 xfs_defer_finish+0x1c/0x180 fs/xfs/libxfs/xfs_defer.c:741
 xfs_bunmapi_range+0xc4/0x140 fs/xfs/libxfs/xfs_bmap.c:6178
 xfs_itruncate_extents_flags+0x306/0x990 fs/xfs/xfs_inode.c:1066
 xfs_itruncate_extents fs/xfs/xfs_inode.h:604 [inline]
 xfs_inactive_truncate+0x125/0x1b0 fs/xfs/xfs_inode.c:1168
 xfs_inactive+0x949/0xcd0 fs/xfs/xfs_inode.c:1454
 xfs_inodegc_inactivate fs/xfs/xfs_icache.c:1944 [inline]
 xfs_inodegc_worker+0x31b/0x7c0 fs/xfs/xfs_icache.c:1990
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

The buggy address belongs to the object at ffff88805f82f7e0
 which belongs to the cache xfs_buf_item of size 272
The buggy address is located 112 bytes inside of
 freed 272-byte region [ffff88805f82f7e0, ffff88805f82f8f0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5f82f
anon flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88801ef9a140 0000000000000000 0000000000000001
raw: 0000000000000000 00000000800c000c 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 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 6113, tgid 6113 (syz.1.18), ts 84620086100, free_ts 84595180484
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851
 prep_new_page mm/page_alloc.c:1859 [inline]
 get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3858
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5148
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416
 alloc_slab_page mm/slub.c:2487 [inline]
 allocate_slab+0x8a/0x370 mm/slub.c:2655
 new_slab mm/slub.c:2709 [inline]
 ___slab_alloc+0xbeb/0x1410 mm/slub.c:3891
 __slab_alloc mm/slub.c:3981 [inline]
 __slab_alloc_node mm/slub.c:4056 [inline]
 slab_alloc_node mm/slub.c:4217 [inline]
 kmem_cache_alloc_noprof+0x283/0x3c0 mm/slub.c:4236
 xfs_buf_item_init+0x66/0x670 fs/xfs/xfs_buf_item.c:878
 xlog_recover_validate_buf_type+0xa2e/0xdb0 fs/xfs/xfs_buf_item_recover.c:452
 xlog_recover_buf_commit_pass2+0xe2b/0x1a10 fs/xfs/xfs_buf_item_recover.c:1098
 xlog_recover_items_pass2+0xe6/0x130 fs/xfs/xfs_log_recover.c:2009
 xlog_recover_commit_trans+0x658/0x8a0 fs/xfs/xfs_log_recover.c:2078
 xlog_recovery_process_trans+0xab/0x1c0 fs/xfs/xfs_log_recover.c:2309
 xlog_recover_process_ophdr+0x2f5/0x380 fs/xfs/xfs_log_recover.c:2455
 xlog_recover_process_data+0x1a5/0x430 fs/xfs/xfs_log_recover.c:2500
 xlog_do_recovery_pass+0x9cd/0xc30 fs/xfs/xfs_log_recover.c:3235
page last free pid 6113 tgid 6113 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1395 [inline]
 __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2895
 pagetable_free include/linux/mm.h:2917 [inline]
 pagetable_dtor_free include/linux/mm.h:3015 [inline]
 __tlb_remove_table+0x2d2/0x3b0 include/asm-generic/tlb.h:220
 __tlb_remove_table_free mm/mmu_gather.c:227 [inline]
 tlb_remove_table_rcu+0x85/0x100 mm/mmu_gather.c:290
 rcu_do_batch kernel/rcu/tree.c:2605 [inline]
 rcu_core+0xca8/0x1770 kernel/rcu/tree.c:2861
 handle_softirqs+0x286/0x870 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 invoke_softirq kernel/softirq.c:453 [inline]
 __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702

Memory state around the buggy address:
 ffff88805f82f700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88805f82f780: fb fb fb fb fc fc fc fc fc fc fc fc fa fb fb fb
>ffff88805f82f800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                 ^
 ffff88805f82f880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc
 ffff88805f82f900: fc fc fc fc fc fc fa fb fb fb fb fb fb fb fb fb
==================================================================

Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Assets (help?)	Manager	Title
2025/08/17 15:10	linux-next	931e46dcbc7e	1804e95e	.config	console log	report	syz / log	C		[disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)]	ci-upstream-linux-next-kasan-gce-root	KASAN: slab-use-after-free Read in xlog_cil_push_work
2025/08/17 12:59	linux-next	931e46dcbc7e	1804e95e	.config	console log	report	syz / log			[disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)]	ci-upstream-linux-next-kasan-gce-root	KASAN: slab-use-after-free Read in xlog_cil_push_work