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Date: Wed, 17 Apr 2024 21:08:23 -0700
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Subject: [syzbot] [net?] KMSAN: uninit-value in hsr_get_node (3)
From: syzbot <syzbot+a81f2759d022496b40ab@syzkaller.appspotmail.com>
To: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, 
	linux-kernel@vger.kernel.org, netdev@vger.kernel.org, pabeni@redhat.com, 
	syzkaller-bugs@googlegroups.com
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Hello,

syzbot found the following issue on:

HEAD commit:    0bbac3facb5d Linux 6.9-rc4
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=15d9a36d180000
kernel config:  https://syzkaller.appspot.com/x/.config?x=87a805e655619c64
dashboard link: https://syzkaller.appspot.com/bug?extid=a81f2759d022496b40ab
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=14069fcb180000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=155da7cb180000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/93eb2bab28b5/disk-0bbac3fa.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/47a883d2dfaa/vmlinux-0bbac3fa.xz
kernel image: https://storage.googleapis.com/syzbot-assets/6bc56900ec1d/bzImage-0bbac3fa.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a81f2759d022496b40ab@syzkaller.appspotmail.com

syz_tun: entered promiscuous mode
batadv_slave_0: entered promiscuous mode
=====================================================
BUG: KMSAN: uninit-value in hsr_get_node+0xab0/0xad0 net/hsr/hsr_framereg.c:250
 hsr_get_node+0xab0/0xad0 net/hsr/hsr_framereg.c:250
 fill_frame_info net/hsr/hsr_forward.c:577 [inline]
 hsr_forward_skb+0x330/0x30e0 net/hsr/hsr_forward.c:615
 hsr_handle_frame+0xa20/0xb50 net/hsr/hsr_slave.c:69
 __netif_receive_skb_core+0x1cff/0x6190 net/core/dev.c:5432
 __netif_receive_skb_one_core net/core/dev.c:5536 [inline]
 __netif_receive_skb+0xca/0xa00 net/core/dev.c:5652
 netif_receive_skb_internal net/core/dev.c:5738 [inline]
 netif_receive_skb+0x58/0x660 net/core/dev.c:5798
 tun_rx_batched+0x3ee/0x980 drivers/net/tun.c:1549
 tun_get_user+0x5566/0x69e0 drivers/net/tun.c:2002
 tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2048
 call_write_iter include/linux/fs.h:2110 [inline]
 new_sync_write fs/read_write.c:497 [inline]
 vfs_write+0xb63/0x1520 fs/read_write.c:590
 ksys_write+0x20f/0x4c0 fs/read_write.c:643
 __do_sys_write fs/read_write.c:655 [inline]
 __se_sys_write fs/read_write.c:652 [inline]
 __x64_sys_write+0x93/0xe0 fs/read_write.c:652
 x64_sys_call+0x3062/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at:
 __alloc_pages+0x9d6/0xe70 mm/page_alloc.c:4598
 alloc_pages_mpol+0x299/0x990 mm/mempolicy.c:2264
 alloc_pages+0x1bf/0x1e0 mm/mempolicy.c:2335
 skb_page_frag_refill+0x2bf/0x7c0 net/core/sock.c:2921
 tun_build_skb drivers/net/tun.c:1679 [inline]
 tun_get_user+0x1258/0x69e0 drivers/net/tun.c:1819
 tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2048
 call_write_iter include/linux/fs.h:2110 [inline]
 new_sync_write fs/read_write.c:497 [inline]
 vfs_write+0xb63/0x1520 fs/read_write.c:590
 ksys_write+0x20f/0x4c0 fs/read_write.c:643
 __do_sys_write fs/read_write.c:655 [inline]
 __se_sys_write fs/read_write.c:652 [inline]
 __x64_sys_write+0x93/0xe0 fs/read_write.c:652
 x64_sys_call+0x3062/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

CPU: 1 PID: 5050 Comm: syz-executor387 Not tainted 6.9.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
=====================================================


---
This report is generated by a bot. It may contain errors.
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If the report is already addressed, let syzbot know by replying with:
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