=====================================================
BUG: KMSAN: uninit-value in hsr_register_frame_in+0x374/0x380 net/hsr/hsr_framereg.c:468
 hsr_register_frame_in+0x374/0x380 net/hsr/hsr_framereg.c:468
 hsr_forward_skb+0xe95/0x3630 net/hsr/hsr_forward.c:622
 hsr_handle_frame+0x9e3/0xac0 net/hsr/hsr_slave.c:69
 __netif_receive_skb_core+0x2197/0x6260 net/core/dev.c:5297
 __netif_receive_skb_one_core net/core/dev.c:5403 [inline]
 __netif_receive_skb+0xf2/0x630 net/core/dev.c:5519
 netif_receive_skb_internal+0x1b3/0x3c0 net/core/dev.c:5605
 netif_receive_skb+0x49/0x360 net/core/dev.c:5664
 tun_rx_batched+0xadd/0xd50
 tun_get_user+0x479d/0x4e80 drivers/net/tun.c:1985
 tun_chr_write_iter+0x407/0x580 drivers/net/tun.c:2015
 call_write_iter include/linux/fs.h:2050 [inline]
 new_sync_write fs/read_write.c:504 [inline]
 vfs_write+0x119f/0x1e80 fs/read_write.c:591
 ksys_write+0x28b/0x510 fs/read_write.c:644
 __do_sys_write fs/read_write.c:656 [inline]
 __se_sys_write fs/read_write.c:653 [inline]
 __x64_sys_write+0xdb/0x120 fs/read_write.c:653
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x51/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Uninit was stored to memory at:
 hsr_fill_frame_info+0x74e/0x770 net/hsr/hsr_forward.c:536
 fill_frame_info net/hsr/hsr_forward.c:605 [inline]
 hsr_forward_skb+0x7c4/0x3630 net/hsr/hsr_forward.c:619
 hsr_handle_frame+0x9e3/0xac0 net/hsr/hsr_slave.c:69
 __netif_receive_skb_core+0x2197/0x6260 net/core/dev.c:5297
 __netif_receive_skb_one_core net/core/dev.c:5403 [inline]
 __netif_receive_skb+0xf2/0x630 net/core/dev.c:5519
 netif_receive_skb_internal+0x1b3/0x3c0 net/core/dev.c:5605
 netif_receive_skb+0x49/0x360 net/core/dev.c:5664
 tun_rx_batched+0xadd/0xd50
 tun_get_user+0x479d/0x4e80 drivers/net/tun.c:1985
 tun_chr_write_iter+0x407/0x580 drivers/net/tun.c:2015
 call_write_iter include/linux/fs.h:2050 [inline]
 new_sync_write fs/read_write.c:504 [inline]
 vfs_write+0x119f/0x1e80 fs/read_write.c:591
 ksys_write+0x28b/0x510 fs/read_write.c:644
 __do_sys_write fs/read_write.c:656 [inline]
 __se_sys_write fs/read_write.c:653 [inline]
 __x64_sys_write+0xdb/0x120 fs/read_write.c:653
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x51/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Uninit was created at:
 __alloc_pages+0xbbf/0x1090 mm/page_alloc.c:5448
 alloc_pages+0xa08/0xd50
 skb_page_frag_refill+0x35e/0x8f0 net/core/sock.c:2731
 tun_build_skb+0x233/0x2420 drivers/net/tun.c:1658
 tun_get_user+0x10e2/0x4e80 drivers/net/tun.c:1798
 tun_chr_write_iter+0x407/0x580 drivers/net/tun.c:2015
 call_write_iter include/linux/fs.h:2050 [inline]
 new_sync_write fs/read_write.c:504 [inline]
 vfs_write+0x119f/0x1e80 fs/read_write.c:591
 ksys_write+0x28b/0x510 fs/read_write.c:644
 __do_sys_write fs/read_write.c:656 [inline]
 __se_sys_write fs/read_write.c:653 [inline]
 __x64_sys_write+0xdb/0x120 fs/read_write.c:653
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x51/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x44/0xae

CPU: 1 PID: 19997 Comm: syz-executor.5 Not tainted 5.18.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
=====================================================