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

Status: upstream: reported syz repro on 2026/08/03 04:18
Reported-by: syzbot+3fe274c1ae4fad0ec84a@syzkaller.appspotmail.com
First crash: 5d18h, last: 5d13h
Bug presence (1)
Date Name Commit Repro Result
2026/08/07 upstream (ToT) c0a27675eaf0 syz Failed due to an error; will retry later
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: slab-out-of-bounds Read in copy_from_sockptr prio:high net 17 syz 20 7h20m 4d08h 23/29 upstream: reported syz repro on 2026/08/04 14:54

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+0x44/0x1a8 include/linux/sockptr.h:59
Read of size 84 at addr ffff0000f0afe000 by task syz.0.17/4484

CPU: 0 PID: 4484 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/02/2026
Call trace:
 dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:158
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
 __dump_stack+0x30/0x40 lib/dump_stack.c:88
 dump_stack_lvl+0xf4/0x15c lib/dump_stack.c:106
 print_address_description+0x88/0x218 mm/kasan/report.c:316
 print_report+0x50/0x68 mm/kasan/report.c:420
 kasan_report+0xa8/0xfc mm/kasan/report.c:524
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x258/0x290 mm/kasan/generic.c:189
 memcpy+0x48/0x90 mm/kasan/shadow.c:65
 copy_from_sockptr_offset include/linux/sockptr.h:49 [inline]
 copy_from_sockptr+0x44/0x1a8 include/linux/sockptr.h:59
 vcc_setsockopt+0x17c/0x694 net/atm/common.c:775
 pvc_setsockopt+0x84/0xb0 net/atm/pvc.c:72
 __sys_setsockopt+0x2fc/0x50c net/socket.c:2288
 __do_sys_setsockopt net/socket.c:2299 [inline]
 __se_sys_setsockopt net/socket.c:2296 [inline]
 __arm64_sys_setsockopt+0xc0/0xdc net/socket.c:2296
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

Allocated by task 4484:
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4c/0x80 mm/kasan/common.c:53
 kasan_save_alloc_info+0x24/0x30 mm/kasan/generic.c:505
 ____kasan_kmalloc mm/kasan/common.c:375 [inline]
 __kasan_kmalloc+0xa0/0xb8 mm/kasan/common.c:384
 kasan_kmalloc include/linux/kasan.h:211 [inline]
 __do_kmalloc_node mm/slab_common.c:936 [inline]
 __kmalloc+0xd8/0x180 mm/slab_common.c:949
 kmalloc include/linux/slab.h:568 [inline]
 kzalloc include/linux/slab.h:699 [inline]
 sockopt_alloc_buf kernel/bpf/cgroup.c:1781 [inline]
 __cgroup_bpf_run_filter_setsockopt+0x1e4/0xbe0 kernel/bpf/cgroup.c:1822
 __sys_setsockopt+0x4c0/0x50c net/socket.c:2271
 __do_sys_setsockopt net/socket.c:2299 [inline]
 __se_sys_setsockopt net/socket.c:2296 [inline]
 __arm64_sys_setsockopt+0xc0/0xdc net/socket.c:2296
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

The buggy address belongs to the object at ffff0000f0afe000
 which belongs to the cache kmalloc-128 of size 128
The buggy address is located 0 bytes inside of
 128-byte region [ffff0000f0afe000, ffff0000f0afe080)

The buggy address belongs to the physical page:
page:0000000006654382 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x130afe
flags: 0x5ffc00000000200(slab|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000000200 0000000000000000 dead000000000122 ffff0000c0002300
raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000f0afdf00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff0000f0afdf80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff0000f0afe000: 00 00 00 00 00 00 05 fc fc fc fc fc fc fc fc fc
                                     ^
 ffff0000f0afe080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff0000f0afe100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/03 09:19 linux-6.1.y fb28aa725e05 e611ffe1 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in copy_from_sockptr
2026/08/03 08:33 linux-6.1.y fb28aa725e05 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in copy_from_sockptr
2026/08/03 04:18 linux-6.1.y fb28aa725e05 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in copy_from_sockptr
* Struck through repros no longer work on HEAD.