===================================================== BUG: KMSAN: uninit-value in virtio_net_hdr_to_skb+0x1414/0x14f0 include/linux/virtio_net.h:86 CPU: 1 PID: 4243 Comm: syz-executor.2 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] 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:00007fdf57765188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9 RDX: 0000000000000139 RSI: 0000000020000300 RDI: 0000000000000003 RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80 R13: 0000000000a9fb1f R14: 00007fdf57765300 R15: 0000000000022000 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:120 [inline] kmsan_internal_poison_shadow+0x66/0xd0 mm/kmsan/kmsan.c:103 kmsan_slab_alloc+0x8e/0xe0 mm/kmsan/kmsan_hooks.c:76 slab_alloc_node mm/slub.c:2922 [inline] __kmalloc_node+0xa3c/0x1440 mm/slub.c:4116 kmalloc_node include/linux/slab.h:577 [inline] kvmalloc_node+0x201/0x3d0 mm/util.c:587 kvmalloc include/linux/mm.h:785 [inline] lzo_alloc_workspace+0x155/0x500 fs/btrfs/lzo.c:85 alloc_workspace+0x367/0x640 fs/btrfs/compression.c:908 btrfs_init_workspace_manager+0x158/0x4f0 fs/btrfs/compression.c:950 btrfs_init_compress+0x3b/0x45 fs/btrfs/compression.c:1235 init_btrfs_fs+0x94/0x60a fs/btrfs/super.c:2575 do_one_initcall+0x362/0x8d0 init/main.c:1229 do_initcall_level+0x1e7/0x35a init/main.c:1302 do_initcalls+0x127/0x1cb init/main.c:1318 do_basic_setup+0x33/0x36 init/main.c:1338 kernel_init_freeable+0x287/0x3cc init/main.c:1540 kernel_init+0x1f/0x840 init/main.c:1427 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 =====================================================