=====================================================
BUG: KMSAN: uninit-value in hsr_register_frame_in+0x189/0x260 net/hsr/hsr_framereg.c:400
CPU: 1 PID: 29930 Comm: syz-executor.2 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
 hsr_register_frame_in+0x189/0x260 net/hsr/hsr_framereg.c:400
 hsr_forward_skb+0xea1/0x27f0 net/hsr/hsr_forward.c:567
 hsr_handle_frame+0x7f8/0x970 net/hsr/hsr_slave.c:70
 __netif_receive_skb_core+0x1f9d/0x65a0 net/core/dev.c:5279
 __netif_receive_skb_one_core net/core/dev.c:5382 [inline]
 __netif_receive_skb+0xf2/0x640 net/core/dev.c:5498
 netif_receive_skb_internal+0x1ae/0x3e0 net/core/dev.c:5603
 netif_receive_skb+0x4c/0x270 net/core/dev.c:5662
 tun_rx_batched include/linux/skbuff.h:4418 [inline]
 tun_get_user+0x634b/0x6620 drivers/net/tun.c:1896
 tun_chr_write_iter+0x398/0x440 drivers/net/tun.c:1926
 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: 0033:0x4192bf
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 99 fd ff ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 cc fd ff ff 48
RSP: 002b:00007fc2e4f1a150 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004192bf
RDX: 000000000000000e RSI: 0000000020000040 RDI: 00000000000000f0
RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 000000000056bf80
R13: 0000000000a9fb1f R14: 00007fc2e4f1a300 R15: 0000000000022000

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:120 [inline]
 kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:288
 __msan_chain_origin+0x54/0xa0 mm/kmsan/kmsan_instr.c:147
 hsr_fill_frame_info+0x5b3/0x6a0 net/hsr/hsr_forward.c:490
 fill_frame_info net/hsr/hsr_forward.c:547 [inline]
 hsr_forward_skb+0xc4f/0x27f0 net/hsr/hsr_forward.c:564
 hsr_handle_frame+0x7f8/0x970 net/hsr/hsr_slave.c:70
 __netif_receive_skb_core+0x1f9d/0x65a0 net/core/dev.c:5279
 __netif_receive_skb_one_core net/core/dev.c:5382 [inline]
 __netif_receive_skb+0xf2/0x640 net/core/dev.c:5498
 netif_receive_skb_internal+0x1ae/0x3e0 net/core/dev.c:5603
 netif_receive_skb+0x4c/0x270 net/core/dev.c:5662
 tun_rx_batched include/linux/skbuff.h:4418 [inline]
 tun_get_user+0x634b/0x6620 drivers/net/tun.c:1896
 tun_chr_write_iter+0x398/0x440 drivers/net/tun.c:1926
 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

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]
 skb_page_frag_refill+0x194/0x790 net/core/sock.c:2493
 tun_build_skb+0x230/0x1b00 drivers/net/tun.c:1573
 tun_get_user+0x1473/0x6620 drivers/net/tun.c:1712
 tun_chr_write_iter+0x398/0x440 drivers/net/tun.c:1926
 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
=====================================================