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BUG: KASAN: slab-out-of-bounds in memcpy include/linux/fortify-string.h:191 [inline]
BUG: KASAN: slab-out-of-bounds in page_to_skb+0x5cf/0xb70 drivers/net/virtio_net.c:480
Read of size 12 at addr ffff8880155b7800 by task systemd-sysctl/8359

CPU: 0 PID: 8359 Comm: systemd-sysctl Not tainted 5.12.0-rc8-next-20210420-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x141/0x1d7 lib/dump_stack.c:120
 print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:233
 __kasan_report mm/kasan/report.c:419 [inline]
 kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:436
 check_region_inline mm/kasan/generic.c:180 [inline]
 kasan_check_range+0x13d/0x180 mm/kasan/generic.c:186
 memcpy+0x20/0x60 mm/kasan/shadow.c:65
 memcpy include/linux/fortify-string.h:191 [inline]
 page_to_skb+0x5cf/0xb70 drivers/net/virtio_net.c:480
 receive_mergeable drivers/net/virtio_net.c:1009 [inline]
 receive_buf+0x2bc0/0x6250 drivers/net/virtio_net.c:1119
 virtnet_receive drivers/net/virtio_net.c:1411 [inline]
 virtnet_poll+0x568/0x10b0 drivers/net/virtio_net.c:1516
 __napi_poll+0xaf/0x440 net/core/dev.c:6962
 napi_poll net/core/dev.c:7029 [inline]
 net_rx_action+0x801/0xb40 net/core/dev.c:7116
 __do_softirq+0x29b/0x9fe kernel/softirq.c:559
 invoke_softirq kernel/softirq.c:433 [inline]
 __irq_exit_rcu+0x136/0x200 kernel/softirq.c:637
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649
 common_interrupt+0xa4/0xd0 arch/x86/kernel/irq.c:240
 </IRQ>
 asm_common_interrupt+0x1e/0x40 arch/x86/include/asm/idtentry.h:623
RIP: 0010:lock_is_held_type+0xfd/0x140 kernel/locking/lockdep.c:5560
Code: 00 00 b8 ff ff ff ff 65 0f c1 05 4e ef ee 76 83 f8 01 75 29 9c 58 f6 c4 02 75 3d 48 f7 04 24 00 02 00 00 74 01 fb 48 83 c4 08 <44> 89 e8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 45 31 ed eb b9 0f 0b 48
RSP: 0018:ffffc9000c1ffa48 EFLAGS: 00000286
RAX: 0000000000000046 RBX: 0000000000000001 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000
RBP: ffffffff8bf76520 R08: 0000000000000000 R09: ffffffff8dc87617
R10: fffffbfff1b90ec2 R11: 0000000000000000 R12: ffff888018a25580
R13: 0000000000000000 R14: 00000000ffffffff R15: ffff888018a25f80
 lock_is_held include/linux/lockdep.h:283 [inline]
 rcu_read_lock_sched_held+0x3a/0x70 kernel/rcu/update.c:125
 trace_lock_acquire include/trace/events/lock.h:13 [inline]
 lock_acquire+0x58a/0x740 kernel/locking/lockdep.c:5483
 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151
 spin_lock include/linux/spinlock.h:359 [inline]
 browse_rb mm/mmap.c:358 [inline]
 validate_mm+0x440/0x810 mm/mmap.c:425
 remove_vma_list mm/mmap.c:2661 [inline]
 __do_munmap+0x8a5/0x11a0 mm/mmap.c:2914
 do_munmap mm/mmap.c:2922 [inline]
 munmap_vma_range mm/mmap.c:604 [inline]
 mmap_region+0x85a/0x1730 mm/mmap.c:1755
 do_mmap+0xcff/0x11d0 mm/mmap.c:1586
 vm_mmap_pgoff+0x1b7/0x290 mm/util.c:519
 ksys_mmap_pgoff+0x4a8/0x620 mm/mmap.c:1637
 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f28f0a9c30a
Code: 89 f5 41 54 49 89 fc 55 53 74 35 49 63 e8 48 63 da 4d 89 f9 49 89 e8 4d 63 d6 48 89 da 4c 89 ee 4c 89 e7 b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 4e 5b 5d 41 5c 41 5d 41 5e 41 5f c3 0f 1f 00
RSP: 002b:00007ffd08e8db08 EFLAGS: 00000206 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f28f0a9c30a
RDX: 0000000000000003 RSI: 0000000000002000 RDI: 00007f28eec32000
RBP: 0000000000000003 R08: 0000000000000003 R09: 0000000000002000
R10: 0000000000000812 R11: 0000000000000206 R12: 00007f28eec32000
R13: 0000000000002000 R14: 0000000000000812 R15: 0000000000002000

Allocated by task 6399:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:428 [inline]
 ____kasan_kmalloc mm/kasan/common.c:507 [inline]
 ____kasan_kmalloc mm/kasan/common.c:466 [inline]
 __kasan_kmalloc+0x9b/0xd0 mm/kasan/common.c:516
 kmalloc include/linux/slab.h:563 [inline]
 tomoyo_realpath_from_path+0xc3/0x620 security/tomoyo/realpath.c:254
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_number_perm+0x1d5/0x590 security/tomoyo/file.c:723
 tomoyo_path_mknod+0x10d/0x190 security/tomoyo/tomoyo.c:240
 security_path_mknod+0xf9/0x170 security/security.c:1131
 may_o_create fs/namei.c:3036 [inline]
 lookup_open.isra.0+0x475/0x13d0 fs/namei.c:3178
 open_last_lookups fs/namei.c:3285 [inline]
 path_openat+0x9af/0x27d0 fs/namei.c:3491
 do_filp_open+0x190/0x3d0 fs/namei.c:3521
 do_sys_openat2+0x16d/0x420 fs/open.c:1187
 do_sys_open fs/open.c:1203 [inline]
 __do_sys_open fs/open.c:1211 [inline]
 __se_sys_open fs/open.c:1207 [inline]
 __x64_sys_open+0x119/0x1c0 fs/open.c:1207
 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Freed by task 6399:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46
 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:357
 ____kasan_slab_free mm/kasan/common.c:360 [inline]
 ____kasan_slab_free mm/kasan/common.c:325 [inline]
 __kasan_slab_free+0xfb/0x130 mm/kasan/common.c:368
 kasan_slab_free include/linux/kasan.h:212 [inline]
 slab_free_hook mm/slub.c:1593 [inline]
 slab_free_freelist_hook+0xdf/0x240 mm/slub.c:1618
 slab_free mm/slub.c:3178 [inline]
 kfree+0xe5/0x7f0 mm/slub.c:4245
 tomoyo_realpath_from_path+0x191/0x620 security/tomoyo/realpath.c:291
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_number_perm+0x1d5/0x590 security/tomoyo/file.c:723
 tomoyo_path_mknod+0x10d/0x190 security/tomoyo/tomoyo.c:240
 security_path_mknod+0xf9/0x170 security/security.c:1131
 may_o_create fs/namei.c:3036 [inline]
 lookup_open.isra.0+0x475/0x13d0 fs/namei.c:3178
 open_last_lookups fs/namei.c:3285 [inline]
 path_openat+0x9af/0x27d0 fs/namei.c:3491
 do_filp_open+0x190/0x3d0 fs/namei.c:3521
 do_sys_openat2+0x16d/0x420 fs/open.c:1187
 do_sys_open fs/open.c:1203 [inline]
 __do_sys_open fs/open.c:1211 [inline]
 __se_sys_open fs/open.c:1207 [inline]
 __x64_sys_open+0x119/0x1c0 fs/open.c:1207
 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

The buggy address belongs to the object at ffff8880155b6000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 2048 bytes to the right of
 4096-byte region [ffff8880155b6000, ffff8880155b7000)
The buggy address belongs to the page:
page:ffffea0000556c00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x155b0
head:ffffea0000556c00 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 dead000000000100 dead000000000122 ffff888010c42140
raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880155b7700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880155b7780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880155b7800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                   ^
 ffff8880155b7880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880155b7900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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