[Android 5.15] KASAN: slab-out-of-bounds Read in hci_sock_setsockopt

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 13d6d33696ef Merge 5.15.200 into android13-5.15-lts
git tree: android13-5.15-lts
console output: https://syzkaller.appspot.com/x/log.txt?x=17a533b2580000
kernel config: https://syzkaller.appspot.com/x/.config?x=deffac0a782f1cb0
dashboard link: https://syzkaller.appspot.com/bug?extid=badc3c56f2aa7037b3b0
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=166fb994580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1556aaaa580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/49c205e65f10/disk-13d6d336.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e3df4a3942b9/vmlinux-13d6d336.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ac1426590472/bzImage-13d6d336.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+badc3c...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-out-of-bounds in copy_from_sockptr_offset include/linux/sockptr.h:49 [inline]
BUG: KASAN: slab-out-of-bounds in copy_from_sockptr include/linux/sockptr.h:55 [inline]
BUG: KASAN: slab-out-of-bounds in hci_sock_setsockopt+0x7f1/0x820 net/bluetooth/hci_sock.c:1925
Read of size 4 at addr ffff88810ca9ce63 by task syz.2.17/370

CPU: 1 PID: 370 Comm: syz.2.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
<TASK>
__dump_stack+0x21/0x30 lib/dump_stack.c:88
dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106
print_address_description+0x7f/0x2c0 mm/kasan/report.c:248
__kasan_report mm/kasan/report.c:427 [inline]
kasan_report+0xf1/0x140 mm/kasan/report.c:444
__asan_report_load_n_noabort+0xf/0x20 mm/kasan/report_generic.c:319
copy_from_sockptr_offset include/linux/sockptr.h:49 [inline]
copy_from_sockptr include/linux/sockptr.h:55 [inline]
hci_sock_setsockopt+0x7f1/0x820 net/bluetooth/hci_sock.c:1925
__sys_setsockopt+0x2e9/0x470 net/socket.c:2202
__do_sys_setsockopt net/socket.c:2213 [inline]
__se_sys_setsockopt net/socket.c:2210 [inline]
__x64_sys_setsockopt+0xbf/0xd0 net/socket.c:2210
x64_sys_call+0x982/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:55
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7ff430351f79
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:00007ffde2da8a68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007ff4305cbfa0 RCX: 00007ff430351f79
RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000000000000008
RBP: 00007ff4303e87e0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000200000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff4305cbfac R14: 00007ff4305cbfa0 R15: 00007ff4305cbfa0
</TASK>

Allocated by task 370:
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track mm/kasan/common.c:45 [inline]
set_alloc_info mm/kasan/common.c:433 [inline]
____kasan_kmalloc mm/kasan/common.c:512 [inline]
__kasan_kmalloc+0xda/0x110 mm/kasan/common.c:521
kasan_kmalloc include/linux/kasan.h:227 [inline]
__kmalloc+0x13d/0x2c0 mm/slub.c:4436
kmalloc include/linux/slab.h:624 [inline]
__cgroup_bpf_run_filter_setsockopt+0x8e7/0xaa0 kernel/bpf/cgroup.c:1511
__sys_setsockopt+0x40e/0x470 net/socket.c:2185
__do_sys_setsockopt net/socket.c:2213 [inline]
__se_sys_setsockopt net/socket.c:2210 [inline]
__x64_sys_setsockopt+0xbf/0xd0 net/socket.c:2210
x64_sys_call+0x982/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:55
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0

The buggy address belongs to the object at ffff88810ca9ce60
which belongs to the cache kmalloc-8 of size 8
The buggy address is located 3 bytes inside of
8-byte region [ffff88810ca9ce60, ffff88810ca9ce68)
The buggy address belongs to the page:
page:ffffea000432a700 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10ca9c
flags: 0x4000000000000200(slab|zone=1)
raw: 4000000000000200 ffffea000432a5c0 0000000800000008 ffff888100042300
raw: 0000000000000000 0000000080660066 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 0x12a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY), pid 1, ts 3067712302, free_ts 0
set_page_owner include/linux/page_owner.h:33 [inline]
post_alloc_hook+0x192/0x1b0 mm/page_alloc.c:2605
prep_new_page+0x1c/0x110 mm/page_alloc.c:2611
get_page_from_freelist+0x2d3a/0x2dc0 mm/page_alloc.c:4485
__alloc_pages+0x1a2/0x460 mm/page_alloc.c:5808
alloc_slab_page mm/slub.c:-1 [inline]
allocate_slab mm/slub.c:1937 [inline]
new_slab+0xa1/0x4d0 mm/slub.c:2000
___slab_alloc+0x381/0x810 mm/slub.c:3033
__slab_alloc+0x49/0x90 mm/slub.c:3120
slab_alloc_node mm/slub.c:3211 [inline]
slab_alloc mm/slub.c:3255 [inline]
__kmalloc_track_caller+0x169/0x2c0 mm/slub.c:4954
kstrdup+0x36/0x70 mm/util.c:64
get_permissions_callback+0x46/0xa0 security/selinux/ss/services.c:3449
hashtab_map+0xf4/0x1f0 security/selinux/ss/hashtab.c:96
security_get_permissions+0x105/0x330 security/selinux/ss/services.c:3480
sel_make_perm_files security/selinux/selinuxfs.c:1876 [inline]
sel_make_class_dir_entries security/selinux/selinuxfs.c:1937 [inline]
sel_make_classes security/selinux/selinuxfs.c:1968 [inline]
sel_make_policy_nodes+0xd95/0x1360 security/selinux/selinuxfs.c:572
sel_write_load+0x3dc/0x600 security/selinux/selinuxfs.c:652
vfs_write+0x3f9/0xfd0 fs/read_write.c:592
ksys_write+0x149/0x250 fs/read_write.c:647
page_owner free stack trace missing

Memory state around the buggy address:
ffff88810ca9cd00: fc fc fc fc fb fc fc fc fc 06 fc fc fc fc 05 fc
ffff88810ca9cd80: fc fc fc fb fc fc fc fc 05 fc fc fc fc fb fc fc
>ffff88810ca9ce00: fc fc 05 fc fc fc fc fb fc fc fc fc 01 fc fc fc
^
ffff88810ca9ce80: fc 05 fc fc fc fc fb fc fc fc fc fb fc fc fc fc
ffff88810ca9cf00: fb fc fc fc fc fb fc fc fc fc fa fc fc fc fc fb
==================================================================


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