KASAN: stack-out-of-bounds Read in xfs_buf

Kernel	Title	Rank 🛈	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
linux-6.6	KASAN: stack-out-of-bounds Read in xfs_buf_lock	17				1	29d	29d	0/2	upstream: reported on 2025/10/17 03:43
upstream	KASAN: stack-out-of-bounds Read in xfs_buf_lock xfs	17	C	error	unreliable	866	298d	1069d	0/29	auto-obsoleted due to no activity on 2025/04/01 11:07
linux-6.1	KASAN: stack-out-of-bounds Read in xfs_buf_lock	17				1	871d	871d	0/3	auto-obsoleted due to no activity on 2023/10/06 04:59

BTRFS info (device loop2): enabling ssd optimizations ================================================================== BUG: KASAN: stack-out-of-bounds in __lock_acquire+0x77/0x1f80 kernel/locking/lockdep.c:4918 Read of size 8 at addr ffffc900038bf8f8 by task syz-executor.2/21051 CPU: 1 PID: 21051 Comm: syz-executor.2 Not tainted 6.1.61-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 print_address_description mm/kasan/report.c:284 [inline] print_report+0x15f/0x4f0 mm/kasan/report.c:395 kasan_report+0x136/0x160 mm/kasan/report.c:495 __lock_acquire+0x77/0x1f80 kernel/locking/lockdep.c:4918 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5661 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 down+0x35/0xb0 kernel/locking/semaphore.c:59 xfs_buf_lock+0x171/0x5b0 fs/xfs/xfs_buf.c:1120 xfs_buf_delwri_submit_buffers+0x154/0x9a0 fs/xfs/xfs_buf.c:2164 xfs_buf_delwri_submit+0xb6/0x260 fs/xfs/xfs_buf.c:2242 xfs_qm_shrink_scan+0x1ca/0x3d0 fs/xfs/xfs_qm.c:514 do_shrink_slab+0x597/0xed0 mm/vmscan.c:846 shrink_slab+0x237/0x8b0 mm/vmscan.c:1006 drop_slab_node mm/vmscan.c:1041 [inline] drop_slab+0x163/0x290 mm/vmscan.c:1051 drop_caches_sysctl_handler+0xb3/0x160 fs/drop_caches.c:66 proc_sys_call_handler+0x541/0x8a0 fs/proc/proc_sysctl.c:604 do_iter_write+0x6e6/0xc50 fs/read_write.c:861 iter_file_splice_write+0x806/0xfa0 fs/splice.c:686 do_splice_from fs/splice.c:764 [inline] direct_splice_actor+0xe3/0x1c0 fs/splice.c:931 splice_direct_to_actor+0x4c0/0xbd0 fs/splice.c:886 do_splice_direct+0x27f/0x3c0 fs/splice.c:974 do_sendfile+0x61c/0xff0 fs/read_write.c:1255 __do_sys_sendfile64 fs/read_write.c:1317 [inline] __se_sys_sendfile64+0xfc/0x1e0 fs/read_write.c:1309 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fec8c27cae9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fec8cf8d0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007fec8c39bf80 RCX: 00007fec8c27cae9 RDX: 0000000020002080 RSI: 0000000000000006 RDI: 0000000000000007 RBP: 00007fec8c2c847a R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000023b R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fec8c39bf80 R15: 00007fff6071ab18 </TASK> The buggy address belongs to the virtual mapping at [ffffc900038b8000, ffffc900038c1000) created by: copy_process+0x637/0x4060 kernel/fork.c:2098 The buggy address belongs to the physical page: page:ffffea0001f7af80 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7debe memcg:ffff88807e152082 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 0000000000000000 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000000000 00000001ffffffff ffff88807e152082 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x102dc2(GFP_HIGHUSER|__GFP_NOWARN|__GFP_ZERO), pid 2, tgid 2 (kthreadd), ts 879108248300, free_ts 872647159538 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x18d/0x1b0 mm/page_alloc.c:2513 prep_new_page mm/page_alloc.c:2520 [inline] get_page_from_freelist+0x31a1/0x3320 mm/page_alloc.c:4279 __alloc_pages+0x28d/0x770 mm/page_alloc.c:5545 vm_area_alloc_pages mm/vmalloc.c:2983 [inline] __vmalloc_area_node mm/vmalloc.c:3051 [inline] __vmalloc_node_range+0x96c/0x1460 mm/vmalloc.c:3223 alloc_thread_stack_node kernel/fork.c:311 [inline] dup_task_struct+0x3e5/0x6d0 kernel/fork.c:988 copy_process+0x637/0x4060 kernel/fork.c:2098 kernel_clone+0x222/0x920 kernel/fork.c:2682 kernel_thread+0x152/0x1d0 kernel/fork.c:2742 create_kthread kernel/kthread.c:399 [inline] kthreadd+0x596/0x760 kernel/kthread.c:746 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1440 [inline] free_pcp_prepare mm/page_alloc.c:1490 [inline] free_unref_page_prepare+0xf63/0x1120 mm/page_alloc.c:3358 free_unref_page+0x33/0x3e0 mm/page_alloc.c:3453 kasan_depopulate_vmalloc_pte+0x66/0x80 mm/kasan/shadow.c:375 apply_to_pte_range mm/memory.c:2645 [inline] apply_to_pmd_range mm/memory.c:2689 [inline] apply_to_pud_range mm/memory.c:2725 [inline] apply_to_p4d_range mm/memory.c:2761 [inline] __apply_to_page_range+0x9c5/0xcc0 mm/memory.c:2795 kasan_release_vmalloc+0x96/0xb0 mm/kasan/shadow.c:492 __purge_vmap_area_lazy+0x157c/0x1720 mm/vmalloc.c:1774 drain_vmap_area_work+0x3c/0xd0 mm/vmalloc.c:1803 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 Memory state around the buggy address: ffffc900038bf780: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 00 00 ffffc900038bf800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffffc900038bf880: 00 00 00 00 00 00 00 00 00 00 00 00 f3 f3 f3 f3 ^ ffffc900038bf900: f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00 ffffc900038bf980: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 f3 f3 ==================================================================