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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 ffff888013d1f800 by task systemd-udevd/4835

CPU: 0 PID: 4835 Comm: systemd-udevd Not tainted 5.12.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __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:232
 __kasan_report mm/kasan/report.c:399 [inline]
 kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:416
 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+0x2b82/0x6220 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/0x9f6 kernel/softirq.c:345
 invoke_softirq kernel/softirq.c:221 [inline]
 __irq_exit_rcu kernel/softirq.c:422 [inline]
 irq_exit_rcu+0x134/0x200 kernel/softirq.c:434
 common_interrupt+0x51/0xd0 arch/x86/kernel/irq.c:240
 asm_common_interrupt+0x1e/0x40 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x557f3ed8c290
Code: 4c 8b 5c 24 10 4c 8b 54 24 18 4d 39 c1 0f 84 f7 00 00 00 43 80 3c 13 2f 0f 84 1c 01 00 00 43 80 3c 14 2f 0f 84 11 01 00 00 90 <48> 8b 1b 48 39 1c 24 0f 84 63 01 00 00 4c 8b 7b 48 4c 39 7c 24 08
RSP: 002b:00007ffdaefc5e80 EFLAGS: 00000286
RAX: 00000000fffffc00 RBX: 0000557f3f3f1600 RCX: 000000000000742f
RDX: 00000000000000e6 RSI: 0000557f3f34963e RDI: 0000557f3f3f0d4e
RBP: 000000000000042d R08: 000000000000001a R09: 000000000000001a
R10: 000000000000001a R11: 00007f714e6a5060 R12: 0000557f3f3f0d34
R13: 0000000000000000 R14: 0000557f3f27d210 R15: 0000000000001af5

Allocated by task 1:
 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:427 [inline]
 ____kasan_kmalloc mm/kasan/common.c:506 [inline]
 ____kasan_kmalloc mm/kasan/common.c:465 [inline]
 __kasan_kmalloc+0x99/0xc0 mm/kasan/common.c:515
 kmalloc include/linux/slab.h:559 [inline]
 tomoyo_realpath_from_path+0xc3/0x620 security/tomoyo/realpath.c:254
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_perm+0x21b/0x400 security/tomoyo/file.c:822
 security_inode_getattr+0xcf/0x140 security/security.c:1288
 vfs_getattr fs/stat.c:131 [inline]
 vfs_statx+0x164/0x390 fs/stat.c:199
 vfs_fstatat fs/stat.c:217 [inline]
 vfs_lstat include/linux/fs.h:3240 [inline]
 __do_sys_newlstat+0x91/0x110 fs/stat.c:372
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Freed by task 1:
 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+0xf5/0x130 mm/kasan/common.c:367
 kasan_slab_free include/linux/kasan.h:199 [inline]
 slab_free_hook mm/slub.c:1562 [inline]
 slab_free_freelist_hook+0x92/0x210 mm/slub.c:1600
 slab_free mm/slub.c:3161 [inline]
 kfree+0xe5/0x7f0 mm/slub.c:4213
 tomoyo_realpath_from_path+0x191/0x620 security/tomoyo/realpath.c:291
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_perm+0x21b/0x400 security/tomoyo/file.c:822
 security_inode_getattr+0xcf/0x140 security/security.c:1288
 vfs_getattr fs/stat.c:131 [inline]
 vfs_statx+0x164/0x390 fs/stat.c:199
 vfs_fstatat fs/stat.c:217 [inline]
 vfs_lstat include/linux/fs.h:3240 [inline]
 __do_sys_newlstat+0x91/0x110 fs/stat.c:372
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

The buggy address belongs to the object at ffff888013d1e000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 2048 bytes to the right of
 4096-byte region [ffff888013d1e000, ffff888013d1f000)
The buggy address belongs to the page:
page:ffffea00004f4600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x13d18
head:ffffea00004f4600 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head)
raw: 00fff00000010200 dead000000000100 dead000000000122 ffff888010842140
raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888013d1f700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888013d1f780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888013d1f800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                   ^
 ffff888013d1f880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888013d1f900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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