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BUG: KASAN: global-out-of-bounds in memcmp+0x2a/0x6c lib/string.c:694
Read of size 1 at addr ffffffff85d8d8c0 by task syz-executor.0/4616

CPU: 0 PID: 4616 Comm: syz-executor.0 Tainted: G        W          6.2.0-rc1-syzkaller #0
Hardware name: riscv-virtio,qemu (DT)
Call Trace:
[<ffffffff8000b9ea>] dump_backtrace+0x2e/0x3c arch/riscv/kernel/stacktrace.c:121
[<ffffffff83402b96>] show_stack+0x34/0x40 arch/riscv/kernel/stacktrace.c:127
[<ffffffff83442726>] __dump_stack lib/dump_stack.c:88 [inline]
[<ffffffff83442726>] dump_stack_lvl+0xe0/0x14c lib/dump_stack.c:106
[<ffffffff83409674>] print_address_description mm/kasan/report.c:306 [inline]
[<ffffffff83409674>] print_report+0x1e4/0x4c0 mm/kasan/report.c:417
[<ffffffff804ead14>] kasan_report+0xb8/0xe6 mm/kasan/report.c:517
[<ffffffff804ebb00>] check_region_inline mm/kasan/generic.c:183 [inline]
[<ffffffff804ebb00>] __asan_load1+0x62/0x7a mm/kasan/generic.c:253
[<ffffffff833e9684>] memcmp+0x2a/0x6c lib/string.c:694
[<ffffffff82919a7a>] __hw_addr_add_ex+0xf6/0x3f0 net/core/dev_addr_lists.c:88
[<ffffffff8291ba00>] __dev_mc_add net/core/dev_addr_lists.c:867 [inline]
[<ffffffff8291ba00>] dev_mc_add+0x7c/0xc4 net/core/dev_addr_lists.c:885
[<ffffffff82a29d4c>] mrp_init_applicant+0xc2/0x3a0 net/802/mrp.c:872
[<ffffffff83143062>] vlan_mvrp_init_applicant+0x26/0x30 net/8021q/vlan_mvrp.c:57
[<ffffffff8313d960>] register_vlan_dev+0x140/0x578 net/8021q/vlan.c:170
[<ffffffff8313e590>] register_vlan_device net/8021q/vlan.c:277 [inline]
[<ffffffff8313e590>] vlan_ioctl_handler+0x7f8/0xb76 net/8021q/vlan.c:621
[<ffffffff8289fa50>] sock_ioctl+0x1ac/0x650 net/socket.c:1250
[<ffffffff8057afa2>] vfs_ioctl fs/ioctl.c:51 [inline]
[<ffffffff8057afa2>] __do_sys_ioctl fs/ioctl.c:870 [inline]
[<ffffffff8057afa2>] sys_ioctl+0x112/0x14c fs/ioctl.c:856
[<ffffffff80005ff6>] ret_from_syscall+0x0/0x2

The buggy address belongs to the variable:
 vlan_mrp_app+0x60/0x2060

The buggy address belongs to the physical page:
page:ff1c00000217e340 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x85f8d
flags: 0xffe000000001000(reserved|node=0|zone=0|lastcpupid=0x7ff)
raw: 0ffe000000001000 ff1c00000217e348 ff1c00000217e348 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner info is not present (never set?)

Memory state around the buggy address:
 ffffffff85d8d780: 00 00 00 00 00 00 00 00 f9 f9 f9 f9 00 00 00 00
 ffffffff85d8d800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffffff85d8d880: 00 00 00 00 00 00 00 00 f9 f9 f9 f9 00 00 00 00
                                           ^
 ffffffff85d8d900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffffff85d8d980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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