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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: 14429 Comm: syz-executor.4 Tainted: G        W         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]
 aio_write+0x833/0xad0 fs/aio.c:1581
 __io_submit_one fs/aio.c:1840 [inline]
 io_submit_one+0x1d1a/0x4230 fs/aio.c:1883
 __do_sys_io_submit fs/aio.c:1942 [inline]
 __se_sys_io_submit+0x35b/0x7a0 fs/aio.c:1912
 __x64_sys_io_submit+0x4a/0x70 fs/aio.c:1912
 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:00007fe1f0fc4188 EFLAGS: 00000246 ORIG_RAX: 00000000000000d1
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9
RDX: 0000000020000080 RSI: 0000000000000001 RDI: 00007fe1f0fa3000
RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80
R13: 0000000000a9fb1f R14: 00007fe1f0fc4300 R15: 0000000000022000

Uninit was created at:
 kmsan_save_stack_with_flags+0x3c/0x90 mm/kmsan/kmsan.c:120
 kmsan_alloc_page+0xd0/0x1e0 mm/kmsan/kmsan_shadow.c:273
 __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]
 alloc_slab_page mm/slub.c:1653 [inline]
 allocate_slab+0x364/0x1260 mm/slub.c:1793
 new_slab mm/slub.c:1856 [inline]
 new_slab_objects mm/slub.c:2602 [inline]
 ___slab_alloc+0xd42/0x1930 mm/slub.c:2765
 __slab_alloc mm/slub.c:2805 [inline]
 slab_alloc_node mm/slub.c:2886 [inline]
 slab_alloc mm/slub.c:2931 [inline]
 kmem_cache_alloc+0xc68/0x1030 mm/slub.c:2936
 mqueue_alloc_inode+0x54/0xb0 ipc/mqueue.c:486
 alloc_inode fs/inode.c:234 [inline]
 new_inode_pseudo+0xa7/0x580 fs/inode.c:928
 new_inode+0x5a/0x3d0 fs/inode.c:957
 mqueue_get_inode ipc/mqueue.c:299 [inline]
 mqueue_fill_super+0x13d/0x6e0 ipc/mqueue.c:413
 vfs_get_super fs/super.c:1139 [inline]
 get_tree_keyed+0x224/0x440 fs/super.c:1195
 mqueue_get_tree+0x92/0xc0 ipc/mqueue.c:427
 vfs_get_tree+0xd8/0x5e0 fs/super.c:1497
 fc_mount+0x4f/0x160 fs/namespace.c:993
 mq_create_mount ipc/mqueue.c:470 [inline]
 mq_init_ns+0x625/0x8f0 ipc/mqueue.c:1685
 create_ipc_ns ipc/namespace.c:58 [inline]
 copy_ipcs+0x51f/0x9f0 ipc/namespace.c:84
 create_new_namespaces+0x4c0/0x1270 kernel/nsproxy.c:90
 unshare_nsproxy_namespaces+0x268/0x340 kernel/nsproxy.c:226
 ksys_unshare+0xa98/0x1490 kernel/fork.c:2995
 __do_sys_unshare kernel/fork.c:3063 [inline]
 __se_sys_unshare+0x41/0x60 kernel/fork.c:3061
 __x64_sys_unshare+0x32/0x50 kernel/fork.c:3061
 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48
 entry_SYSCALL_64_after_hwframe+0x44/0xae
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