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: 11d, last: 7h57m
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 25 3d22h 9d21h 25/29 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 8 at addr ffff0000ef134500 by task syz.0.17/4505

CPU: 0 PID: 4505 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/07/2026
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+0x1b0/0x694 net/atm/common.c:789
 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 4505:
 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]
 __cgroup_bpf_run_filter_setsockopt+0xa1c/0xbe0 kernel/bpf/cgroup.c:1873
 __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 ffff0000ef134500
 which belongs to the cache kmalloc-128 of size 128
The buggy address is located 0 bytes inside of
 128-byte region [ffff0000ef134500, ffff0000ef134580)

The buggy address belongs to the physical page:
page:00000000b96b4d1c refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x12f134
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:
 ffff0000ef134400: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc
 ffff0000ef134480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff0000ef134500: 04 fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                   ^
 ffff0000ef134580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff0000ef134600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Crashes (9):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/14 04:42 linux-6.1.y e4f7d8be268e b13552fe .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
2026/08/14 04:16 linux-6.1.y e4f7d8be268e b13552fe .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
2026/08/10 07:47 linux-6.1.y e4f7d8be268e 5d63f80b .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 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
2026/08/14 03:50 linux-6.1.y e4f7d8be268e b13552fe .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
2026/08/14 03:48 linux-6.1.y e4f7d8be268e b13552fe .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
2026/08/10 06:32 linux-6.1.y e4f7d8be268e 5d63f80b .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 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.