==================================================================
BUG: KASAN: slab-out-of-bounds in __bpf_get_stackid+0x6fa/0x960 kernel/bpf/stackmap.c:274
Write of size 88 at addr ffff88811dc54110 by task syz.3.202/1059

CPU: 1 PID: 1059 Comm: syz.3.202 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <IRQ>
 __dump_stack+0x21/0x24 lib/dump_stack.c:88
 dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106
 print_address_description+0x71/0x200 mm/kasan/report.c:316
 print_report+0x4a/0x60 mm/kasan/report.c:420
 kasan_report+0x122/0x150 mm/kasan/report.c:524
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x249/0x2a0 mm/kasan/generic.c:189
 memcpy+0x44/0x70 mm/kasan/shadow.c:66
 __bpf_get_stackid+0x6fa/0x960 kernel/bpf/stackmap.c:274
 ____bpf_get_stackid_pe kernel/bpf/stackmap.c:365 [inline]
 bpf_get_stackid_pe+0x2ee/0x400 kernel/bpf/stackmap.c:334
 bpf_prog_1649ecc1a5870555+0x21/0x31
 bpf_dispatcher_nop_func include/linux/bpf.h:987 [inline]
 __bpf_prog_run include/linux/filter.h:607 [inline]
 bpf_prog_run include/linux/filter.h:614 [inline]
 bpf_overflow_handler+0x3d0/0x5e0 kernel/events/core.c:10238
 __perf_event_overflow+0x437/0x620 kernel/events/core.c:9448
 perf_swevent_hrtimer+0x400/0x5b0 kernel/events/core.c:10879
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x3bb/0x8e0 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x3c7/0x8c0 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline]
 __sysvec_apic_timer_interrupt+0x11e/0x440 arch/x86/kernel/apic/apic.c:1124
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1118
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:should_fail_ex+0x14a/0x520 lib/fault-inject.c:106
Code: 04 00 00 00 e8 17 dd 2a ff f0 45 29 3c 24 eb 4b 65 4c 8b 25 b8 9c 76 7d 49 81 c4 0c 0b 00 00 4c 89 e3 48 c1 eb 03 0f b6 04 13 <84> c0 0f 85 a8 02 00 00 45 8b 2c 24 45 85 ed 0f 84 d7 fe ff ff 41
RSP: 0018:ffffc900007bf9f8 EFLAGS: 00000a07
RAX: 0000000000000000 RBX: 1ffff11023a308f9 RCX: ffff88811d183cc0
RDX: dffffc0000000000 RSI: 0000000000000001 RDI: ffffffff871ce040
RBP: ffffc900007bfa40 R08: ffffc900007bfbf7 R09: ffffc900007bfbe0
R10: dffffc0000000000 R11: fffff520000f7f7f R12: ffff88811d1847cc
R13: dffffc0000000000 R14: ffffffff871ce040 R15: 0000000000000001
 should_fail+0xb/0x10 lib/fault-inject.c:157
 should_fail_futex kernel/futex/core.c:83 [inline]
 get_futex_key+0x143/0xb10 kernel/futex/core.c:241
 futex_wake+0x150/0x8e0 kernel/futex/waitwake.c:156
 do_futex+0x2bf/0x430 kernel/futex/syscalls.c:141
 __do_sys_futex kernel/futex/syscalls.c:213 [inline]
 __se_sys_futex+0x136/0x310 kernel/futex/syscalls.c:194
 __x64_sys_futex+0xe5/0x100 kernel/futex/syscalls.c:194
 x64_sys_call+0x7ec/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:203
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fe4a719c799
Code: ff c3 66 2e 0f 1f 84 00 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
RSP: 002b:00007fe4a80a20e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007fe4a7415fa8 RCX: 00007fe4a719c799
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007fe4a7415fac
RBP: 00007fe4a7415fa0 R08: 001f7cf69e734968 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe4a7416038 R14: 00007ffcee5c0ee0 R15: 00007ffcee5c0fc8
 </TASK>

Allocated by task 1059:
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:53
 kasan_save_alloc_info+0x25/0x30 mm/kasan/generic.c:505
 ____kasan_kmalloc mm/kasan/common.c:380 [inline]
 __kasan_kmalloc+0x95/0xb0 mm/kasan/common.c:389
 kasan_kmalloc include/linux/kasan.h:212 [inline]
 __do_kmalloc_node mm/slab_common.c:938 [inline]
 __kmalloc_node+0xb2/0x1e0 mm/slab_common.c:945
 kmalloc_node include/linux/slab.h:589 [inline]
 __bpf_map_area_alloc kernel/bpf/syscall.c:328 [inline]
 bpf_map_area_alloc+0x4b/0xe0 kernel/bpf/syscall.c:341
 prealloc_elems_and_freelist+0x8a/0x1e0 kernel/bpf/stackmap.c:51
 stack_map_alloc+0x3a7/0x530 kernel/bpf/stackmap.c:117
 find_and_alloc_map kernel/bpf/syscall.c:133 [inline]
 map_create+0x49c/0xd80 kernel/bpf/syscall.c:1126
 __sys_bpf+0x34e/0x850 kernel/bpf/syscall.c:4987
 __do_sys_bpf kernel/bpf/syscall.c:5109 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5107 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5107
 x64_sys_call+0x488/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:322
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

The buggy address belongs to the object at ffff88811dc54100
 which belongs to the cache kmalloc-64 of size 64
The buggy address is located 16 bytes inside of
 64-byte region [ffff88811dc54100, ffff88811dc54140)

The buggy address belongs to the physical page:
page:ffffea0004771500 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11dc54
flags: 0x4000000000000200(slab|zone=1)
raw: 4000000000000200 ffffea0004d4f900 dead000000000006 ffff888100042780
raw: 0000000000000000 0000000000200020 00000001ffffffff 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 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 284, tgid 284 (syz-executor), ts 37987674324, free_ts 37987553226
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2670
 prep_new_page+0x1c/0x110 mm/page_alloc.c:2677
 get_page_from_freelist+0x2d12/0x2d80 mm/page_alloc.c:4583
 __alloc_pages+0x1fa/0x610 mm/page_alloc.c:5924
 alloc_slab_page+0x6e/0xf0 include/linux/gfp.h:-1
 allocate_slab mm/slub.c:1967 [inline]
 new_slab+0x98/0x3d0 mm/slub.c:2020
 ___slab_alloc+0x6bd/0xb20 mm/slub.c:3177
 __slab_alloc+0x5e/0xa0 mm/slub.c:3263
 slab_alloc_node mm/slub.c:3348 [inline]
 __kmem_cache_alloc_node+0x203/0x2c0 mm/slub.c:3423
 __do_kmalloc_node mm/slab_common.c:937 [inline]
 __kmalloc_node+0xa1/0x1e0 mm/slab_common.c:945
 kmalloc_node include/linux/slab.h:589 [inline]
 kvmalloc_node+0x28a/0x460 mm/util.c:592
 kvmalloc include/linux/slab.h:716 [inline]
 simple_xattr_alloc+0x43/0xa0 fs/xattr.c:1008
 shmem_initxattrs+0x8d/0x1e0 mm/shmem.c:3294
 security_inode_init_security+0x2a9/0x3d0 security/security.c:1133
 shmem_mknod+0xbb/0x1d0 mm/shmem.c:2951
 shmem_mkdir+0x2f/0x60 mm/shmem.c:3000
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 free_pages_prepare mm/page_alloc.c:1578 [inline]
 free_pcp_prepare mm/page_alloc.c:1652 [inline]
 free_unref_page_prepare+0x742/0x750 mm/page_alloc.c:3618
 free_unref_page+0x95/0x540 mm/page_alloc.c:3716
 free_the_page mm/page_alloc.c:863 [inline]
 __free_pages+0x67/0x100 mm/page_alloc.c:6014
 __free_slab+0xca/0x1a0 mm/slub.c:2044
 free_slab mm/slub.c:2059 [inline]
 discard_slab+0x29/0x40 mm/slub.c:2065
 __slab_free+0x201/0x280 mm/slub.c:3625
 do_slab_free mm/slub.c:3666 [inline]
 ___cache_free+0xbf/0xd0 mm/slub.c:3722
 qlink_free mm/kasan/quarantine.c:168 [inline]
 qlist_free_all+0xc6/0x140 mm/kasan/quarantine.c:187
 kasan_quarantine_reduce+0x14a/0x170 mm/kasan/quarantine.c:294
 __kasan_slab_alloc+0x24/0x80 mm/kasan/common.c:311
 kasan_slab_alloc include/linux/kasan.h:202 [inline]
 slab_post_alloc_hook+0x4f/0x2d0 mm/slab.h:768
 slab_alloc_node mm/slub.c:3382 [inline]
 slab_alloc mm/slub.c:3392 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3399 [inline]
 kmem_cache_alloc+0x16e/0x330 mm/slub.c:3408
 getname_flags+0xb9/0x500 fs/namei.c:139
 getname fs/namei.c:218 [inline]
 __do_sys_mkdirat fs/namei.c:4153 [inline]
 __se_sys_mkdirat fs/namei.c:4151 [inline]
 __x64_sys_mkdirat+0x7c/0xa0 fs/namei.c:4151
 x64_sys_call+0x73d/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:259
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76

Memory state around the buggy address:
 ffff88811dc54000: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
 ffff88811dc54080: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc
>ffff88811dc54100: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc
                                  ^
 ffff88811dc54180: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff88811dc54200: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
==================================================================
----------------
Code disassembly (best guess):
   0:	04 00                	add    $0x0,%al
   2:	00 00                	add    %al,(%rax)
   4:	e8 17 dd 2a ff       	call   0xff2add20
   9:	f0 45 29 3c 24       	lock sub %r15d,(%r12)
   e:	eb 4b                	jmp    0x5b
  10:	65 4c 8b 25 b8 9c 76 	mov    %gs:0x7d769cb8(%rip),%r12        # 0x7d769cd0
  17:	7d
  18:	49 81 c4 0c 0b 00 00 	add    $0xb0c,%r12
  1f:	4c 89 e3             	mov    %r12,%rbx
  22:	48 c1 eb 03          	shr    $0x3,%rbx
  26:	0f b6 04 13          	movzbl (%rbx,%rdx,1),%eax
* 2a:	84 c0                	test   %al,%al <-- trapping instruction
  2c:	0f 85 a8 02 00 00    	jne    0x2da
  32:	45 8b 2c 24          	mov    (%r12),%r13d
  36:	45 85 ed             	test   %r13d,%r13d
  39:	0f 84 d7 fe ff ff    	je     0xffffff16
  3f:	41                   	rex.B