syzbot

==================================================================
BUG: KASAN: slab-out-of-bounds in __bpf_get_stackid+0x6fa/0x960 kernel/bpf/stackmap.c:274
Write of size 56 at addr ffff888111e27d10 by task syz.2.17/363

CPU: 1 PID: 363 Comm: syz.2.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <#DB>
 __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_a82986b851e905af+0x21/0x33
 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_overflow kernel/events/core.c:9524 [inline]
 perf_swevent_event+0x2f7/0x530 kernel/events/core.c:-1
 perf_bp_event+0x28c/0x330 kernel/events/core.c:10430
 hw_breakpoint_handler arch/x86/kernel/hw_breakpoint.c:555 [inline]
 hw_breakpoint_exceptions_notify+0x182/0x550 arch/x86/kernel/hw_breakpoint.c:586
 notifier_call_chain kernel/notifier.c:87 [inline]
 atomic_notifier_call_chain kernel/notifier.c:225 [inline]
 notify_die+0x12a/0x1e0 kernel/notifier.c:593
 notify_debug+0x24/0x30 arch/x86/kernel/traps.c:1018
 exc_debug_kernel arch/x86/kernel/traps.c:1075 [inline]
 exc_debug+0xde/0x130 arch/x86/kernel/traps.c:1175
 asm_exc_debug+0x1a/0x40 arch/x86/include/asm/idtentry.h:648
RIP: 0010:copy_user_enhanced_fast_string+0xa/0x40 arch/x86/lib/copy_user_64.S:166
Code: ff c9 75 f2 89 d1 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 31 c0 0f 01 ca c3 8d 0c ca 89 ca eb 20 0f 01 cb 83 fa 40 72 38 89 d1 <f3> a4 31 c0 0f 01 ca c3 89 ca eb 0a 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc900009c7d28 EFLAGS: 00050202
RAX: ffffffff82688c01 RBX: 0000000000000050 RCX: 000000000000000f
RDX: 0000000000000050 RSI: 0000200000000301 RDI: ffffc900009c7de1
RBP: ffffc900009c7d50 R08: ffffc900009c7def R09: 1ffff92000138fbd
R10: dffffc0000000000 R11: fffff52000138fbe R12: 00007fffffffefb0
R13: 0000000000000050 R14: ffffc900009c7da0 R15: 00002000000002c0
 </#DB>
 <TASK>
 copy_from_user include/linux/uaccess.h:161 [inline]
 copy_from_bpfptr_offset include/linux/bpfptr.h:53 [inline]
 copy_from_bpfptr include/linux/bpfptr.h:59 [inline]
 __sys_bpf+0x2a0/0x850 kernel/bpf/syscall.c:4976
 __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
RIP: 0033:0x7feaf859c819
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:00007ffe5780b578 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007feaf8815fa0 RCX: 00007feaf859c819
RDX: 0000000000000050 RSI: 00002000000002c0 RDI: 000000000000001c
RBP: 00007feaf8632c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007feaf8815fac R14: 00007feaf8815fa0 R15: 00007feaf8815fa0
 </TASK>

Allocated by task 363:
 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 ffff888111e27d00
 which belongs to the cache kmalloc-64 of size 64
The buggy address is located 16 bytes inside of
 64-byte region [ffff888111e27d00, ffff888111e27d40)

The buggy address belongs to the physical page:
page:ffffea00044789c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x111e27
flags: 0x4000000000000200(slab|zone=1)
raw: 4000000000000200 0000000000000000 dead000000000001 ffff888100042780
raw: 0000000000000000 0000000080200020 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 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 104, tgid 104 (udevadm), ts 5539800387, free_ts 5539747534
 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+0xa1/0x1e0 mm/slab_common.c:951
 kmalloc include/linux/slab.h:568 [inline]
 kzalloc include/linux/slab.h:699 [inline]
 kobject_get_path+0xbf/0x200 lib/kobject.c:152
 kobject_uevent_env+0x2a0/0x730 lib/kobject_uevent.c:544
 kobject_synth_uevent+0x57e/0xbc0 lib/kobject_uevent.c:208
 uevent_store+0x4b/0x70 drivers/base/core.c:2693
 drv_attr_store+0x88/0xb0 drivers/base/bus.c:77
 sysfs_kf_write+0x137/0x150 fs/sysfs/file.c:136
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_pages+0x82/0x90 mm/page_alloc.c:6025
 selinux_genfs_get_sid+0x20b/0x250 security/selinux/hooks.c:1309
 inode_doinit_with_dentry+0x87a/0xd80 security/selinux/hooks.c:1504
 selinux_d_instantiate+0x27/0x40 security/selinux/hooks.c:6396
 security_d_instantiate+0xb3/0x110 security/security.c:2096
 d_splice_alias+0x6d/0x390 fs/dcache.c:3155
 kernfs_iop_lookup+0x2c2/0x310 fs/kernfs/dir.c:1204
 lookup_open fs/namei.c:3467 [inline]
 open_last_lookups fs/namei.c:3557 [inline]
 path_openat+0x1006/0x2f80 fs/namei.c:3787
 do_filp_open+0x1f1/0x430 fs/namei.c:3817
 do_sys_openat2+0x15e/0x810 fs/open.c:1343
 do_sys_open fs/open.c:1359 [inline]
 __do_sys_openat fs/open.c:1375 [inline]
 __se_sys_openat fs/open.c:1370 [inline]
 __x64_sys_openat+0x136/0x160 fs/open.c:1370
 x64_sys_call+0x783/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:258
 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:
 ffff888111e27c00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff888111e27c80: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
>ffff888111e27d00: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc
                                  ^
 ffff888111e27d80: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff888111e27e00: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================
----------------
Code disassembly (best guess):
   0:	ff c9                	dec    %ecx
   2:	75 f2                	jne    0xfffffff6
   4:	89 d1                	mov    %edx,%ecx
   6:	c1 e9 03             	shr    $0x3,%ecx
   9:	83 e2 07             	and    $0x7,%edx
   c:	f3 48 a5             	rep movsq %ds:(%rsi),%es:(%rdi)
   f:	89 d1                	mov    %edx,%ecx
  11:	f3 a4                	rep movsb %ds:(%rsi),%es:(%rdi)
  13:	31 c0                	xor    %eax,%eax
  15:	0f 01 ca             	clac
  18:	c3                   	ret
  19:	8d 0c ca             	lea    (%rdx,%rcx,8),%ecx
  1c:	89 ca                	mov    %ecx,%edx
  1e:	eb 20                	jmp    0x40
  20:	0f 01 cb             	stac
  23:	83 fa 40             	cmp    $0x40,%edx
  26:	72 38                	jb     0x60
  28:	89 d1                	mov    %edx,%ecx
* 2a:	f3 a4                	rep movsb %ds:(%rsi),%es:(%rdi) <-- trapping instruction
  2c:	31 c0                	xor    %eax,%eax
  2e:	0f 01 ca             	clac
  31:	c3                   	ret
  32:	89 ca                	mov    %ecx,%edx
  34:	eb 0a                	jmp    0x40
  36:	90                   	nop
  37:	90                   	nop
  38:	90                   	nop
  39:	90                   	nop
  3a:	90                   	nop
  3b:	90                   	nop
  3c:	90                   	nop
  3d:	90                   	nop
  3e:	90                   	nop
  3f:	90                   	nop