syzbot


KASAN: slab-out-of-bounds Read in l2cap_sock_setsockopt

Status: upstream: reported C repro on 2026/01/14 12:28
Bug presence: origin:lts
[Documentation on labels]
Reported-by: syzbot+d9c81a0b02cc40bcc07c@syzkaller.appspotmail.com
First crash: 161d, last: 13h17m
Fix bisection: failed (error log, bisect log)
  
Bug presence (2)
Date Name Commit Repro Result
2026/01/14 lts (merge base) 68efe5a6c16a C [report] KASAN: slab-out-of-bounds Read in l2cap_sock_setsockopt
2026/01/14 upstream (ToT) e0d4140e8043 C Didn't crash
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: slab-out-of-bounds Read in l2cap_sock_setsockopt bluetooth 17 C 36 800d 811d 0/29 auto-obsoleted due to no activity on 2024/06/24 18:09
Last patch testing requests (7)
Created Duration User Patch Repo Result
2026/06/21 02:23 12m retest repro android13-5.15-lts log
2026/06/21 02:23 20m retest repro android13-5.15-lts log
2026/06/21 02:23 12m retest repro android13-5.15-lts log
2026/05/11 01:33 20m retest repro android13-5.15-lts report log
2026/04/08 17:53 6m retest repro android13-5.15-lts report log
2026/04/08 17:53 6m retest repro android13-5.15-lts report log
2026/04/08 17:53 14m retest repro android13-5.15-lts report log

Sample crash report:
==================================================================
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 l2cap_sock_setsockopt_old net/bluetooth/l2cap_sock.c:822 [inline]
BUG: KASAN: slab-out-of-bounds in l2cap_sock_setsockopt+0x17a6/0x1e00 net/bluetooth/l2cap_sock.c:914
Read of size 4 at addr ffff88810cabe233 by task syz.2.17/372

CPU: 0 PID: 372 Comm: syz.2.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
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+0x10f/0x150 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]
 l2cap_sock_setsockopt_old net/bluetooth/l2cap_sock.c:822 [inline]
 l2cap_sock_setsockopt+0x17a6/0x1e00 net/bluetooth/l2cap_sock.c:914
 __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: 0033:0x7ff405863e59
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:00007ffca3b44d48 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007ff405adcfa0 RCX: 00007ff405863e59
RDX: 0000000000000003 RSI: 0000000000000006 RDI: 0000000000000004
RBP: 00007ff4058f9e6f R08: 0000000000000002 R09: 0000000000000000
R10: 0000200000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff405adcfac R14: 00007ff405adcfa0 R15: 00007ff405adcfa0
 </TASK>

Allocated by task 372:
 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+0xd4/0x100 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 ffff88810cabe230
 which belongs to the cache kmalloc-8 of size 8
The buggy address is located 3 bytes inside of
 8-byte region [ffff88810cabe230, ffff88810cabe238)
The buggy address belongs to the page:
page:ffffea000432af80 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10cabe
flags: 0x4000000000000200(slab|zone=1)
raw: 4000000000000200 dead000000000100 dead000000000122 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 4747472485, free_ts 0
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x192/0x1b0 mm/page_alloc.c:2607
 prep_new_page+0x1c/0x110 mm/page_alloc.c:2613
 get_page_from_freelist+0x2c3a/0x2cd0 mm/page_alloc.c:4487
 __alloc_pages+0x1a2/0x460 mm/page_alloc.c:5824
 alloc_slab_page mm/slub.c:-1 [inline]
 allocate_slab mm/slub.c:1937 [inline]
 new_slab+0xa0/0x4d0 mm/slub.c:2000
 ___slab_alloc+0x3ac/0x840 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+0x10e/0x370 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+0xd8e/0x1350 security/selinux/selinuxfs.c:572
 sel_write_load+0x3dc/0x600 security/selinux/selinuxfs.c:652
 vfs_write+0x404/0xfd0 fs/read_write.c:592
 ksys_write+0x14a/0x260 fs/read_write.c:647
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88810cabe100: fc fc fc fb fc fc fc fc fa fc fc fc fc fb fc fc
 ffff88810cabe180: fc fc fa fc fc fc fc fa fc fc fc fc fa fc fc fc
>ffff88810cabe200: fc 05 fc fc fc fc 02 fc fc fc fc 05 fc fc fc fc
                                     ^
 ffff88810cabe280: fb fc fc fc fc 05 fc fc fc fc fb fc fc fc fc fb
 ffff88810cabe300: fc fc fc fc fa fc fc fc fc fb fc fc fc fc fb fc
==================================================================

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/06/24 20:55 android13-5.15-lts c85054db4618 302586aa .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in l2cap_sock_setsockopt
2026/01/14 14:53 android13-5.15-lts 050dc55b0457 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in l2cap_sock_setsockopt
2026/01/14 14:01 android13-5.15-lts 050dc55b0457 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in l2cap_sock_setsockopt
2026/01/14 13:07 android13-5.15-lts 050dc55b0457 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in l2cap_sock_setsockopt
2026/01/14 12:15 android13-5.15-lts 050dc55b0457 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in l2cap_sock_setsockopt
2026/01/14 11:14 android13-5.15-lts 050dc55b0457 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in l2cap_sock_setsockopt
* Struck through repros no longer work on HEAD.