[syzbot] [net?] KMSAN: uninit-value in hsr_forward_skb

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 614da38e2f7a Merge tag 'hid-for-linus-2024051401' of git:/..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15b61eee980000
kernel config: https://syzkaller.appspot.com/x/.config?x=f5d2cbf33633f507
dashboard link: https://syzkaller.appspot.com/bug?extid=b78a03b570e0033aba81
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/89eafb874b71/disk-614da38e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/356000512ad9/vmlinux-614da38e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/839c73939115/bzImage-614da38e.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b78a03...@syzkaller.appspotmail.com

ip6gretap0: entered promiscuous mode
syz_tun: entered promiscuous mode
=====================================================
BUG: KMSAN: uninit-value in hsr_forward_skb+0x268c/0x30e0 net/hsr/hsr_forward.c:618
hsr_forward_skb+0x268c/0x30e0 net/hsr/hsr_forward.c:618
hsr_handle_frame+0xa20/0xb50 net/hsr/hsr_slave.c:69
__netif_receive_skb_core+0x1cff/0x6190 net/core/dev.c:5438
__netif_receive_skb_one_core net/core/dev.c:5542 [inline]
__netif_receive_skb+0xca/0xa00 net/core/dev.c:5658
netif_receive_skb_internal net/core/dev.c:5744 [inline]
netif_receive_skb+0x58/0x660 net/core/dev.c:5804
tun_rx_batched+0x3ee/0x980 drivers/net/tun.c:1549
tun_get_user+0x5587/0x6a00 drivers/net/tun.c:2002
tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2048
call_write_iter include/linux/fs.h:2120 [inline]
new_sync_write fs/read_write.c:497 [inline]
vfs_write+0xb31/0x14d0 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 stored to memory at:
hsr_fill_frame_info+0x538/0x540 net/hsr/hsr_forward.c:533
fill_frame_info net/hsr/hsr_forward.c:600 [inline]
hsr_forward_skb+0x6f6/0x30e0 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:5438
__netif_receive_skb_one_core net/core/dev.c:5542 [inline]
__netif_receive_skb+0xca/0xa00 net/core/dev.c:5658
netif_receive_skb_internal net/core/dev.c:5744 [inline]
netif_receive_skb+0x58/0x660 net/core/dev.c:5804
tun_rx_batched+0x3ee/0x980 drivers/net/tun.c:1549
tun_get_user+0x5587/0x6a00 drivers/net/tun.c:2002
tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2048
call_write_iter include/linux/fs.h:2120 [inline]
new_sync_write fs/read_write.c:497 [inline]
vfs_write+0xb31/0x14d0 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+0x1258/0x6a00 drivers/net/tun.c:1819
tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2048
call_write_iter include/linux/fs.h:2120 [inline]
new_sync_write fs/read_write.c:497 [inline]
vfs_write+0xb31/0x14d0 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: 5890 Comm: syz-executor.3 Not tainted 6.9.0-syzkaller-02707-g614da38e2f7a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
=====================================================


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