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BUG: KMSAN: uninit-value in virtio_net_hdr_to_skb+0x1414/0x14f0 include/linux/virtio_net.h:86
CPU: 0 PID: 11104 Comm: syz-executor.5 Not tainted 5.12.0-rc6-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+0x24c/0x2e0 lib/dump_stack.c:120
 kmsan_report+0xfb/0x1e0 mm/kmsan/kmsan_report.c:121
 __msan_warning+0x5c/0xa0 mm/kmsan/kmsan_instr.c:197
 virtio_net_hdr_to_skb+0x1414/0x14f0 include/linux/virtio_net.h:86
 packet_snd net/packet/af_packet.c:2994 [inline]
 packet_sendmsg+0x85b8/0x99d0 net/packet/af_packet.c:3031
 sock_sendmsg_nosec net/socket.c:654 [inline]
 sock_sendmsg net/socket.c:674 [inline]
 sock_write_iter+0x585/0x680 net/socket.c:1001
 call_write_iter include/linux/fs.h:1977 [inline]
 new_sync_write fs/read_write.c:518 [inline]
 vfs_write+0x1083/0x1b00 fs/read_write.c:605
 ksys_write+0x275/0x500 fs/read_write.c:658
 __do_sys_write fs/read_write.c:670 [inline]
 __se_sys_write+0x92/0xb0 fs/read_write.c:667
 __x64_sys_write+0x4a/0x70 fs/read_write.c:667
 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665d9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007faa1900e188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9
RDX: 0000000000000139 RSI: 0000000020000200 RDI: 0000000000000003
RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80
R13: 0000000000a9fb1f R14: 00007faa1900e300 R15: 0000000000022000

Uninit was created at:
 kmsan_save_stack_with_flags+0x3c/0x90 mm/kmsan/kmsan.c:121
 kmsan_alloc_page+0xd0/0x1e0 mm/kmsan/kmsan_shadow.c:274
 __alloc_pages_nodemask+0x827/0xf90 mm/page_alloc.c:5044
 alloc_pages_current+0x7b6/0xb60 mm/mempolicy.c:2277
 alloc_pages include/linux/gfp.h:561 [inline]
 __vmalloc_area_node mm/vmalloc.c:2524 [inline]
 __vmalloc_node_range+0x987/0x1310 mm/vmalloc.c:2590
 __vmalloc_node mm/vmalloc.c:2633 [inline]
 vmalloc+0xe0/0xf0 mm/vmalloc.c:2666
 kcov_remote_start+0x1cd/0x390 kernel/kcov.c:883
 kcov_remote_start_usb include/linux/kcov.h:52 [inline]
 hub_event+0x1b6/0x8870 drivers/usb/core/hub.c:5527
 process_one_work+0x1219/0x1fe0 kernel/workqueue.c:2275
 worker_thread+0x10ec/0x2340 kernel/workqueue.c:2421
 kthread+0x521/0x560 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
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