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

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    7004a2e46d16 Merge tag 'linux_kselftest-nolibc-6.14-rc1' o..
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=171a1c24580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=d6a5cefe7199b4e8
dashboard link: https://syzkaller.appspot.com/bug?extid=b3bcd80232d00091e061
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=16a2a9f8580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12baf618580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/d5b55fed9d79/disk-7004a2e4.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/70382af6f618/vmlinux-7004a2e4.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a7609fc3059d/bzImage-7004a2e4.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b3bcd80232d00091e061@xxxxxxxxxxxxxxxxxxxxxxxxx

=====================================================
BUG: KMSAN: uninit-value in nsim_get_ringparam+0xa8/0xe0 drivers/net/netdevsim/ethtool.c:77
 nsim_get_ringparam+0xa8/0xe0 drivers/net/netdevsim/ethtool.c:77
 ethtool_set_ringparam+0x268/0x570 net/ethtool/ioctl.c:2072
 __dev_ethtool net/ethtool/ioctl.c:3209 [inline]
 dev_ethtool+0x126d/0x2a40 net/ethtool/ioctl.c:3398
 dev_ioctl+0xb0e/0x1280 net/core/dev_ioctl.c:759
 sock_do_ioctl+0x28c/0x540 net/socket.c:1208
 sock_ioctl+0x721/0xd70 net/socket.c:1313
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl+0x246/0x440 fs/ioctl.c:892
 __x64_sys_ioctl+0x96/0xe0 fs/ioctl.c:892
 x64_sys_call+0x19f0/0x3c30 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Local variable kernel_ringparam created at:
 ethtool_set_ringparam+0x96/0x570 net/ethtool/ioctl.c:2063
 __dev_ethtool net/ethtool/ioctl.c:3209 [inline]
 dev_ethtool+0x126d/0x2a40 net/ethtool/ioctl.c:3398

CPU: 0 UID: 0 PID: 5807 Comm: syz-executor164 Not tainted 6.13.0-syzkaller-04788-g7004a2e46d16 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
=====================================================


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