================================================================== BUG: KASAN: use-after-free in memcpy include/linux/fortify-string.h:191 [inline] BUG: KASAN: use-after-free in page_to_skb+0x5cf/0xb70 drivers/net/virtio_net.c:480 Read of size 12 at addr ffff88801605f800 by task systemd-udevd/6446 CPU: 1 PID: 6446 Comm: systemd-udevd 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: __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 asm_common_interrupt+0x1e/0x40 arch/x86/include/asm/idtentry.h:623 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:163 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:197 Code: f0 4d 89 03 e9 f2 fc ff ff b9 ff ff ff ff ba 08 00 00 00 4d 8b 03 48 0f bd ca 49 8b 45 00 48 63 c9 e9 64 ff ff ff 0f 1f 40 00 <65> 8b 05 f9 7b 8d 7e 89 c1 48 8b 34 24 81 e1 00 01 00 00 65 48 8b RSP: 0018:ffffc90003f775a0 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000008 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff88801dcab900 RDI: 0000000000000003 RBP: ffff888012ae9780 R08: 0000000000000000 R09: 0000000000000008 R10: ffffffff8397a117 R11: 0000000000000010 R12: 0000000000000026 R13: 0000000000000305 R14: dffffc0000000000 R15: 0000000000000000 tomoyo_domain_quota_is_ok+0x31a/0x550 security/tomoyo/util.c:1092 tomoyo_supervisor+0x2f2/0xf00 security/tomoyo/common.c:2089 tomoyo_audit_path_log security/tomoyo/file.c:168 [inline] tomoyo_path_permission security/tomoyo/file.c:587 [inline] tomoyo_path_permission+0x270/0x3a0 security/tomoyo/file.c:573 tomoyo_check_open_permission+0x30f/0x380 security/tomoyo/file.c:780 tomoyo_file_open security/tomoyo/tomoyo.c:313 [inline] tomoyo_file_open+0xa3/0xd0 security/tomoyo/tomoyo.c:308 security_file_open+0x52/0x4f0 security/security.c:1633 do_dentry_open+0x358/0x11b0 fs/open.c:813 do_open fs/namei.c:3361 [inline] path_openat+0x1c09/0x27d0 fs/namei.c:3494 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 RIP: 0033:0x7f8de7bc16f0 Code: 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 83 3d 19 30 2c 00 00 75 10 b8 02 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 fe 9d 01 00 48 89 04 24 RSP: 002b:00007fffaec75c48 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f8de7bc16f0 RDX: 0000000000000180 RSI: 00000000000800c2 RDI: 000055fe29763980 RBP: 000000000003a2f8 R08: 000000000000fcfe R09: 0000000000000030 R10: 0000000000000000 R11: 0000000000000246 R12: 000055fe29763996 R13: 8421084210842109 R14: 00000000000800c2 R15: 00007f8de7c4f540 Allocated by task 6392: 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:558 [inline] kzalloc include/linux/slab.h:688 [inline] uevent_show+0x15c/0x390 drivers/base/core.c:2343 dev_attr_show+0x4b/0x90 drivers/base/core.c:2050 sysfs_kf_seq_show+0x1f8/0x400 fs/sysfs/file.c:61 seq_read_iter+0x4d3/0x1220 fs/seq_file.c:227 kernfs_fop_read_iter+0x44f/0x5f0 fs/kernfs/file.c:241 call_read_iter include/linux/fs.h:2108 [inline] new_sync_read+0x41e/0x6e0 fs/read_write.c:415 vfs_read+0x35c/0x570 fs/read_write.c:496 ksys_read+0x12d/0x250 fs/read_write.c:634 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae Freed by task 6392: 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 uevent_show+0x2c4/0x390 drivers/base/core.c:2356 dev_attr_show+0x4b/0x90 drivers/base/core.c:2050 sysfs_kf_seq_show+0x1f8/0x400 fs/sysfs/file.c:61 seq_read_iter+0x4d3/0x1220 fs/seq_file.c:227 kernfs_fop_read_iter+0x44f/0x5f0 fs/kernfs/file.c:241 call_read_iter include/linux/fs.h:2108 [inline] new_sync_read+0x41e/0x6e0 fs/read_write.c:415 vfs_read+0x35c/0x570 fs/read_write.c:496 ksys_read+0x12d/0x250 fs/read_write.c:634 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 ffff88801605e000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 2048 bytes to the right of 4096-byte region [ffff88801605e000, ffff88801605f000) The buggy address belongs to the page: page:ffffea0000581600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x16058 head:ffffea0000581600 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 dead000000000100 dead000000000122 ffff888011042140 raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88801605f700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88801605f780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88801605f800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88801605f880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88801605f900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================