Subject: KMSAN: uninit-value in hsr_register_frame_in

From: syzbot <[email-masked]>
Date: Mon, 11 Feb 2019 13:53:03 -0800

Hello,

syzbot found the following crash on:

HEAD commit:    fa1981bee40f kmsan: fix defconfig build
git tree:       kmsan
console output: https://syzkaller.appspot.com/x/log.txt?x=12c53624c00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=52c9737ec5618f82
dashboard link: https://syzkaller.appspot.com/bug?extid=b8152ab439b9c5174ffd
compiler:       clang version 8.0.0 (trunk 350509)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11a4f787400000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1797e960c00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: [email-masked]

IPv6: ADDRCONF(NETDEV_UP): hsr0: link is not ready
IPv6: ADDRCONF(NETDEV_CHANGE): hsr0: link becomes ready
IPv6: ADDRCONF(NETDEV_UP): vxcan1: link is not ready
8021q: adding VLAN 0 to HW filter on device batadv0
==================================================================
BUG: KMSAN: uninit-value in hsr_register_frame_in+0x12c/0x200  
net/hsr/hsr_framereg.c:318
CPU: 0 PID: 10753 Comm: syz-executor132 Not tainted 5.0.0-rc1+ #9
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Call Trace:
  __dump_stack lib/dump_stack.c:77 [inline]
  dump_stack+0x173/0x1d0 lib/dump_stack.c:113
  kmsan_report+0x12e/0x2a0 mm/kmsan/kmsan.c:600
  __msan_warning+0x82/0xf0 mm/kmsan/kmsan_instr.c:313
  hsr_register_frame_in+0x12c/0x200 net/hsr/hsr_framereg.c:318
  hsr_forward_skb+0xd64/0x2e30 net/hsr/hsr_forward.c:372
  hsr_dev_xmit+0xf8/0x160 net/hsr/hsr_device.c:243
  __netdev_start_xmit include/linux/netdevice.h:4382 [inline]
  netdev_start_xmit include/linux/netdevice.h:4391 [inline]
  xmit_one net/core/dev.c:3278 [inline]
  dev_hard_start_xmit+0x604/0xc40 net/core/dev.c:3294
  __dev_queue_xmit+0x2e48/0x3b80 net/core/dev.c:3864
  dev_queue_xmit+0x4b/0x60 net/core/dev.c:3897
  packet_snd net/packet/af_packet.c:2932 [inline]
  packet_sendmsg+0x79bb/0x9760 net/packet/af_packet.c:2957
  sock_sendmsg_nosec net/socket.c:621 [inline]
  sock_sendmsg net/socket.c:631 [inline]
  __sys_sendto+0x8c4/0xac0 net/socket.c:1788
  __do_sys_sendto net/socket.c:1800 [inline]
  __se_sys_sendto+0x107/0x130 net/socket.c:1796
  __x64_sys_sendto+0x6e/0x90 net/socket.c:1796
  do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291
  entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x441869
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 0f 83 bb 10 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fffa42c7de8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000441869
RDX: 000000000000000e RSI: 00000000200000c0 RDI: 0000000000000003
RBP: 00000000004a8fb0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402db0
R13: 0000000000402e40 R14: 0000000000000000 R15: 0000000000000000

Uninit was stored to memory at:
  kmsan_save_stack_with_flags mm/kmsan/kmsan.c:205 [inline]
  kmsan_save_stack mm/kmsan/kmsan.c:220 [inline]
  kmsan_internal_chain_origin+0x134/0x230 mm/kmsan/kmsan.c:426
  __msan_chain_origin+0x70/0xe0 mm/kmsan/kmsan_instr.c:200
  hsr_add_node net/hsr/hsr_framereg.c:152 [inline]
  hsr_get_node+0xc94/0xe10 net/hsr/hsr_framereg.c:198
  hsr_fill_frame_info net/hsr/hsr_forward.c:327 [inline]
  hsr_forward_skb+0x7e9/0x2e30 net/hsr/hsr_forward.c:370
  hsr_dev_xmit+0xf8/0x160 net/hsr/hsr_device.c:243
  __netdev_start_xmit include/linux/netdevice.h:4382 [inline]
  netdev_start_xmit include/linux/netdevice.h:4391 [inline]
  xmit_one net/core/dev.c:3278 [inline]
  dev_hard_start_xmit+0x604/0xc40 net/core/dev.c:3294
  __dev_queue_xmit+0x2e48/0x3b80 net/core/dev.c:3864
  dev_queue_xmit+0x4b/0x60 net/core/dev.c:3897
  packet_snd net/packet/af_packet.c:2932 [inline]
  packet_sendmsg+0x79bb/0x9760 net/packet/af_packet.c:2957
  sock_sendmsg_nosec net/socket.c:621 [inline]
  sock_sendmsg net/socket.c:631 [inline]
  __sys_sendto+0x8c4/0xac0 net/socket.c:1788
  __do_sys_sendto net/socket.c:1800 [inline]
  __se_sys_sendto+0x107/0x130 net/socket.c:1796
  __x64_sys_sendto+0x6e/0x90 net/socket.c:1796
  do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291
  entry_SYSCALL_64_after_hwframe+0x63/0xe7

Uninit was created at:
  kmsan_save_stack_with_flags mm/kmsan/kmsan.c:205 [inline]
  kmsan_internal_poison_shadow+0x92/0x150 mm/kmsan/kmsan.c:159
  kmsan_kmalloc+0xa6/0x130 mm/kmsan/kmsan_hooks.c:176
  kmsan_slab_alloc+0xe/0x10 mm/kmsan/kmsan_hooks.c:185
  slab_post_alloc_hook mm/slab.h:446 [inline]
  slab_alloc_node mm/slub.c:2754 [inline]
  __kmalloc_node_track_caller+0xe9e/0xff0 mm/slub.c:4377
  __kmalloc_reserve net/core/skbuff.c:140 [inline]
  __alloc_skb+0x309/0xa20 net/core/skbuff.c:208
  alloc_skb include/linux/skbuff.h:1012 [inline]
  alloc_skb_with_frags+0x1c7/0xac0 net/core/skbuff.c:5288
  sock_alloc_send_pskb+0xafd/0x10a0 net/core/sock.c:2091
  packet_alloc_skb net/packet/af_packet.c:2783 [inline]
  packet_snd net/packet/af_packet.c:2876 [inline]
  packet_sendmsg+0x6881/0x9760 net/packet/af_packet.c:2957
  sock_sendmsg_nosec net/socket.c:621 [inline]
  sock_sendmsg net/socket.c:631 [inline]
  __sys_sendto+0x8c4/0xac0 net/socket.c:1788
  __do_sys_sendto net/socket.c:1800 [inline]
  __se_sys_sendto+0x107/0x130 net/socket.c:1796
  __x64_sys_sendto+0x6e/0x90 net/socket.c:1796
  do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291
  entry_SYSCALL_64_after_hwframe+0x63/0xe7
==================================================================

---
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