KMSAN: uninit-value in snd_seq_oss_synth_make_info (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    73d62e81 kmsan: random: prevent boot-time reports in _mix_..
git tree:       https://github.com/google/kmsan.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=10284200d00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=2cdf4151c9653e32
dashboard link: https://syzkaller.appspot.com/bug?extid=e42504ff21cff05a595f
compiler:       clang version 11.0.0 (https://github.com/llvm/llvm-project.git ca2dcbd030eadbf0aa9b660efe864ff08af6e18b)
userspace arch: i386

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

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e42504ff21cff05a595f at syzkaller.appspotmail.com

=====================================================
BUG: KMSAN: uninit-value in strlen lib/string.c:576 [inline]
BUG: KMSAN: uninit-value in strlcpy+0x8c/0x1c0 lib/string.c:143
CPU: 1 PID: 10203 Comm: syz-executor.3 Not tainted 5.10.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x21c/0x280 lib/dump_stack.c:118
 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:118
 __msan_warning+0x5f/0xa0 mm/kmsan/kmsan_instr.c:197
 strlen lib/string.c:576 [inline]
 strlcpy+0x8c/0x1c0 lib/string.c:143
 snd_seq_oss_synth_make_info+0x381/0x820 sound/core/seq/oss/seq_oss_synth.c:619
 snd_seq_oss_synth_info_user sound/core/seq/oss/seq_oss_ioctl.c:24 [inline]
 snd_seq_oss_ioctl+0x12b4/0x2530 sound/core/seq/oss/seq_oss_ioctl.c:139
 odev_ioctl sound/core/seq/oss/seq_oss.c:180 [inline]
 odev_ioctl_compat+0x247/0x290 sound/core/seq/oss/seq_oss.c:190
 __do_compat_sys_ioctl fs/ioctl.c:842 [inline]
 __se_compat_sys_ioctl+0x53d/0x1100 fs/ioctl.c:793
 __ia32_compat_sys_ioctl+0x4a/0x70 fs/ioctl.c:793
 do_syscall_32_irqs_on arch/x86/entry/common.c:80 [inline]
 __do_fast_syscall_32+0x102/0x160 arch/x86/entry/common.c:139
 do_fast_syscall_32+0x6a/0xc0 arch/x86/entry/common.c:162
 do_SYSENTER_32+0x73/0x90 arch/x86/entry/common.c:205
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c
RIP: 0023:0xf7f8c549
Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000f55860cc EFLAGS: 00000296 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00000000c08c5114
RDX: 0000000020000080 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Local variable ----minf at snd_seq_oss_synth_make_info created at:
 snd_seq_oss_synth_make_info+0x22a/0x820 sound/core/seq/oss/seq_oss_synth.c:613
 snd_seq_oss_synth_make_info+0x22a/0x820 sound/core/seq/oss/seq_oss_synth.c:613
=====================================================


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