[v6.6] KASAN: slab-out-of-bounds Write in stack_map_get_build_id_offset

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: a4a971135a2f Linux 6.6.155
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=128ba379580000
kernel config: https://syzkaller.appspot.com/x/.config?x=7be9809cedd6b69c
dashboard link: https://syzkaller.appspot.com/bug?extid=891bd26fad4b84a456b8
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15128349580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=130d1e25580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/ea506a5758e4/disk-a4a97113.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/bc4e839fee7d/vmlinux-a4a97113.xz
kernel image: https://storage.googleapis.com/syzbot-assets/de2b6666ea7c/bzImage-a4a97113.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+891bd2...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-out-of-bounds in stack_map_get_build_id_offset+0x6c0/0x720 kernel/bpf/stackmap.c:144
Write of size 4 at addr ffff8880256fd330 by task syz.0.17/5931

CPU: 1 PID: 5931 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
<TASK>
dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:364 [inline]
print_report+0xa8/0x210 mm/kasan/report.c:468
kasan_report+0x117/0x150 mm/kasan/report.c:581
stack_map_get_build_id_offset+0x6c0/0x720 kernel/bpf/stackmap.c:144
__bpf_get_stackid+0x564/0x900 kernel/bpf/stackmap.c:247
____bpf_get_stackid_pe kernel/bpf/stackmap.c:362 [inline]
bpf_get_stackid_pe+0x343/0x410 kernel/bpf/stackmap.c:331
bpf_prog_2414a5d5030ea31b+0x29/0x2d
bpf_dispatcher_nop_func include/linux/bpf.h:1224 [inline]
__bpf_prog_run include/linux/filter.h:617 [inline]
bpf_prog_run include/linux/filter.h:624 [inline]
bpf_overflow_handler+0x1fc/0x510 kernel/events/core.c:10584
__perf_event_overflow+0x461/0x660 kernel/events/core.c:9720
perf_swevent_overflow kernel/events/core.c:9803 [inline]
perf_swevent_event+0x319/0x570 kernel/events/core.c:9854
do_perf_sw_event kernel/events/core.c:9967 [inline]
___perf_sw_event+0x4ab/0x730 kernel/events/core.c:9998
__perf_sw_event+0x139/0x270 kernel/events/core.c:10010
perf_sw_event include/linux/perf_event.h:1442 [inline]
do_user_addr_fault+0x1242/0x12d0 arch/x86/mm/fault.c:1278
handle_page_fault arch/x86/mm/fault.c:1463 [inline]
exc_page_fault+0x64/0x100 arch/x86/mm/fault.c:1516
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0010:rep_movs_alternative+0x15/0x90 arch/x86/lib/copy_user_64.S:44
Code: 8b 1c 24 4c 8b 64 24 08 48 83 c4 10 c3 cc cc cc cc cc cc cc cc f3 0f 1e fa 48 83 f9 40 73 40 83 f9 08 73 21 85 c9 74 0f 8a 06 <88> 07 48 ff c7 48 ff c6 48 ff c9 75 f1 c3 66 2e 0f 1f 84 00 00 00
RSP: 0018:ffffc9000343ef50 EFLAGS: 00050206
RAX: ffffffff8433b630 RBX: 0000000000000003 RCX: 0000000000000003
RDX: 0000000000000000 RSI: ffff888074e7868c RDI: 000020000000cf3d
RBP: ffff888074e78668 R08: ffff888074e7868e R09: 1ffff1100e9cf0d1
R10: dffffc0000000000 R11: ffffed100e9cf0d2 R12: 000020000000cf40
R13: 0000000000000003 R14: 000020000000cf3d R15: ffff888074e7868c
copy_user_generic arch/x86/include/asm/uaccess_64.h:112 [inline]
raw_copy_to_user arch/x86/include/asm/uaccess_64.h:133 [inline]
_copy_to_user+0x85/0xa0 lib/usercopy.c:41
copy_to_user include/linux/uaccess.h:191 [inline]
bpf_verifier_vlog+0x2f1/0x840 kernel/bpf/log.c:124
verbose+0x11e/0x1a0 kernel/bpf/verifier.c:370
print_insn_state+0x130/0x160 kernel/bpf/verifier.c:1566
do_check+0x4f08/0xd0a0 kernel/bpf/verifier.c:17325
do_check_common+0xacc/0x1410 kernel/bpf/verifier.c:19898
do_check_main kernel/bpf/verifier.c:19961 [inline]
bpf_check+0x65d1/0xec30 kernel/bpf/verifier.c:20629
bpf_prog_load+0x10fa/0x1610 kernel/bpf/syscall.c:2753
__sys_bpf+0x5ba/0x890 kernel/bpf/syscall.c:5478
__do_sys_bpf kernel/bpf/syscall.c:5582 [inline]
__se_sys_bpf kernel/bpf/syscall.c:5580 [inline]
__x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5580
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f267c19e159
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:00007fff6e387af8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f267c425fa0 RCX: 00007f267c19e159
RDX: 0000000000000048 RSI: 0000200000000080 RDI: 0000000000000005
RBP: 00007f267c235024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f267c425fac R14: 00007f267c425fa0 R15: 00007f267c425fa0
</TASK>

Allocated by task 5931:
kasan_save_stack mm/kasan/common.c:46 [inline]
kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
____kasan_kmalloc mm/kasan/common.c:375 [inline]
__kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:384
kasan_kmalloc include/linux/kasan.h:198 [inline]
__do_kmalloc_node mm/slab_common.c:1007 [inline]
__kmalloc_node+0xb6/0x240 mm/slab_common.c:1014
kmalloc_node include/linux/slab.h:620 [inline]
__bpf_map_area_alloc kernel/bpf/syscall.c:303 [inline]
bpf_map_area_alloc+0x5e/0x110 kernel/bpf/syscall.c:316
prealloc_elems_and_freelist+0x86/0x1c0 kernel/bpf/stackmap.c:51
stack_map_alloc+0x32b/0x4b0 kernel/bpf/stackmap.c:114
map_create+0x877/0x12f0 kernel/bpf/syscall.c:1247
__sys_bpf+0x651/0x890 kernel/bpf/syscall.c:5460
__do_sys_bpf kernel/bpf/syscall.c:5582 [inline]
__se_sys_bpf kernel/bpf/syscall.c:5580 [inline]
__x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5580
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2

The buggy address belongs to the object at ffff8880256fd000
which belongs to the cache kmalloc-cg-1k of size 1024
The buggy address is located 0 bytes to the right of
allocated 816-byte region [ffff8880256fd000, ffff8880256fd330)

The buggy address belongs to the physical page:
page:ffffea000095be00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x256f8
head:ffffea000095be00 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff888074f1e601
anon flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888017c4f280 0000000000000000 0000000000000001
raw: 0000000000000000 0000000080100010 00000001ffffffff ffff888074f1e601
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5617, tgid 5617 (sshd-session), ts 67162207479, free_ts 66987254422
set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook+0x1c1/0x200 mm/page_alloc.c:1582
prep_new_page mm/page_alloc.c:1589 [inline]
get_page_from_freelist+0x2181/0x22a0 mm/page_alloc.c:3221
__alloc_pages+0x1f0/0x460 mm/page_alloc.c:4501
alloc_slab_page+0x5d/0x180 mm/slub.c:1881
allocate_slab mm/slub.c:2028 [inline]
new_slab+0x87/0x2d0 mm/slub.c:2081
___slab_alloc+0xc5c/0x12f0 mm/slub.c:3253
__slab_alloc mm/slub.c:3339 [inline]
__slab_alloc_node mm/slub.c:3392 [inline]
slab_alloc_node mm/slub.c:3485 [inline]
__kmem_cache_alloc_node+0x11f/0x250 mm/slub.c:3534
__do_kmalloc_node mm/slab_common.c:1006 [inline]
__kmalloc+0xa7/0x240 mm/slab_common.c:1020
kmalloc_array include/linux/slab.h:637 [inline]
kcalloc include/linux/slab.h:668 [inline]
alloc_pipe_info+0x1f9/0x4b0 fs/pipe.c:813
get_pipe_inode fs/pipe.c:887 [inline]
create_pipe_files+0x87/0x700 fs/pipe.c:919
__do_pipe_flags+0x4c/0x2c0 fs/pipe.c:968
do_pipe2+0xab/0x190 fs/pipe.c:1019
__do_sys_pipe2 fs/pipe.c:1037 [inline]
__se_sys_pipe2 fs/pipe.c:1035 [inline]
__x64_sys_pipe2+0x5a/0x70 fs/pipe.c:1035
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1182 [inline]
free_unref_page_prepare+0x7d7/0x8f0 mm/page_alloc.c:2366
free_unref_page+0x32/0x2e0 mm/page_alloc.c:2459
discard_slab mm/slub.c:2127 [inline]
__unfreeze_partials+0x1cf/0x210 mm/slub.c:2667
put_cpu_partial+0x17c/0x250 mm/slub.c:2743
__slab_free+0x319/0x400 mm/slub.c:3700
qlink_free mm/kasan/quarantine.c:166 [inline]
qlist_free_all+0x75/0xd0 mm/kasan/quarantine.c:185
kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:306
kasan_slab_alloc include/linux/kasan.h:188 [inline]
slab_post_alloc_hook+0x6a/0x4d0 mm/slab.h:770
slab_alloc_node mm/slub.c:3495 [inline]
__kmem_cache_alloc_node+0x194/0x250 mm/slub.c:3534
__do_kmalloc_node mm/slab_common.c:1006 [inline]
__kmalloc+0xa7/0x240 mm/slab_common.c:1020
kmalloc include/linux/slab.h:604 [inline]
tomoyo_add_entry security/tomoyo/common.c:2023 [inline]
tomoyo_supervisor+0xbce/0x1100 security/tomoyo/common.c:2095
tomoyo_audit_net_log security/tomoyo/network.c:367 [inline]
tomoyo_audit_inet_log security/tomoyo/network.c:393 [inline]
tomoyo_inet_entry security/tomoyo/network.c:484 [inline]
tomoyo_check_inet_address+0x5e3/0x910 security/tomoyo/network.c:532
tomoyo_socket_connect_permission+0x1d0/0x270 security/tomoyo/network.c:710
security_socket_connect+0x70/0xa0 security/security.c:4342
__sys_connect_file net/socket.c:2053 [inline]
__sys_connect+0x316/0x470 net/socket.c:2074

Memory state around the buggy address:
ffff8880256fd200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff8880256fd280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880256fd300: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc
^
ffff8880256fd380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff8880256fd400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
----------------
Code disassembly (best guess):
0: 8b 1c 24 mov (%rsp),%ebx
3: 4c 8b 64 24 08 mov 0x8(%rsp),%r12
8: 48 83 c4 10 add $0x10,%rsp
c: c3 ret
d: cc int3
e: cc int3
f: cc int3
10: cc int3
11: cc int3
12: cc int3
13: cc int3
14: cc int3
15: f3 0f 1e fa endbr64
19: 48 83 f9 40 cmp $0x40,%rcx
1d: 73 40 jae 0x5f
1f: 83 f9 08 cmp $0x8,%ecx
22: 73 21 jae 0x45
24: 85 c9 test %ecx,%ecx
26: 74 0f je 0x37
28: 8a 06 mov (%rsi),%al
* 2a: 88 07 mov %al,(%rdi) <-- trapping instruction
2c: 48 ff c7 inc %rdi
2f: 48 ff c6 inc %rsi
32: 48 ff c9 dec %rcx
35: 75 f1 jne 0x28
37: c3 ret
38: 66 data16
39: 2e cs
3a: 0f .byte 0xf
3b: 1f (bad)
3c: 84 00 test %al,(%rax)


---
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