=====================================================
BUG: KMSAN: uninit-value in snd_rawmidi_ioctl+0xd6b/0x12c0 sound/core/rawmidi.c:887
 snd_rawmidi_ioctl+0xd6b/0x12c0 sound/core/rawmidi.c:887
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0x2df/0x4a0 fs/ioctl.c:860
 __x64_sys_ioctl+0xd8/0x110 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Uninit was created at:
 slab_post_alloc_hook mm/slab.h:524 [inline]
 slab_alloc_node mm/slub.c:3251 [inline]
 slab_alloc mm/slub.c:3259 [inline]
 kmem_cache_alloc_trace+0xaca/0x1140 mm/slub.c:3276
 kmalloc include/linux/slab.h:590 [inline]
 snd_rawmidi_open+0x70d/0x1390 sound/core/rawmidi.c:445
 soundcore_open+0xb9c/0xca0 sound/sound_core.c:593
 chrdev_open+0xb91/0xd40 fs/char_dev.c:414
 do_dentry_open+0x1128/0x1bf0 fs/open.c:822
 vfs_open+0xaf/0xe0 fs/open.c:957
 do_open fs/namei.c:3426 [inline]
 path_openat+0x52af/0x5ea0 fs/namei.c:3559
 do_filp_open+0x306/0x760 fs/namei.c:3586
 do_sys_openat2+0x263/0x8f0 fs/open.c:1212
 do_sys_open fs/open.c:1228 [inline]
 __do_sys_openat fs/open.c:1244 [inline]
 __se_sys_openat fs/open.c:1239 [inline]
 __x64_sys_openat+0x35f/0x3c0 fs/open.c:1239
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x44/0xae

CPU: 0 PID: 502 Comm: syz-executor.5 Not tainted 5.16.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
=====================================================