[syzbot] [alsa?] memory leak in snd_seq_create_port

[syzbot <syzbot+cf8e7fa4eeec59b3d485@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    3f01e9fed845 Merge tag 'linux-watchdog-6.5-rc2' of git://w..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14b07344a80000
kernel config:  https://syzkaller.appspot.com/x/.config?x=75da4f0a455bdbd3
dashboard link: https://syzkaller.appspot.com/bug?extid=cf8e7fa4eeec59b3d485
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=15877dc2a80000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12905004a80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/441fb7ea58b8/disk-3f01e9fe.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8fa7790ba0c3/vmlinux-3f01e9fe.xz
kernel image: https://storage.googleapis.com/syzbot-assets/5e7a6471dadf/bzImage-3f01e9fe.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+cf8e7fa4eeec59b3d485@syzkaller.appspotmail.com

Warning: Permanently added '10.128.1.1' (ED25519) to the list of known hosts.
executing program
executing program
BUG: memory leak
unreferenced object 0xffff888100877000 (size 512):
  comm "syz-executor257", pid 5012, jiffies 4294941742 (age 12.790s)
  hex dump (first 32 bytes):
    80 ff 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff8154bf94>] kmalloc_trace+0x24/0x90 mm/slab_common.c:1076
    [<ffffffff83d29e28>] kmalloc include/linux/slab.h:582 [inline]
    [<ffffffff83d29e28>] kzalloc include/linux/slab.h:703 [inline]
    [<ffffffff83d29e28>] snd_seq_create_port+0x78/0x300 sound/core/seq/seq_ports.c:135
    [<ffffffff83d1f681>] snd_seq_ioctl_create_port+0xe1/0x2a0 sound/core/seq/seq_clientmgr.c:1324
    [<ffffffff83d20e5e>] snd_seq_ioctl+0x13e/0x290 sound/core/seq/seq_clientmgr.c:2327
    [<ffffffff81685173>] vfs_ioctl fs/ioctl.c:51 [inline]
    [<ffffffff81685173>] __do_sys_ioctl fs/ioctl.c:870 [inline]
    [<ffffffff81685173>] __se_sys_ioctl fs/ioctl.c:856 [inline]
    [<ffffffff81685173>] __x64_sys_ioctl+0x103/0x140 fs/ioctl.c:856
    [<ffffffff84a77ff9>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
    [<ffffffff84a77ff9>] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
    [<ffffffff84c0008b>] entry_SYSCALL_64_after_hwframe+0x63/0xcd

BUG: memory leak
unreferenced object 0xffff888106742c00 (size 512):
  comm "syz-executor257", pid 5013, jiffies 4294942276 (age 7.450s)
  hex dump (first 32 bytes):
    80 ff 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff8154bf94>] kmalloc_trace+0x24/0x90 mm/slab_common.c:1076
    [<ffffffff83d29e28>] kmalloc include/linux/slab.h:582 [inline]
    [<ffffffff83d29e28>] kzalloc include/linux/slab.h:703 [inline]
    [<ffffffff83d29e28>] snd_seq_create_port+0x78/0x300 sound/core/seq/seq_ports.c:135
    [<ffffffff83d1f681>] snd_seq_ioctl_create_port+0xe1/0x2a0 sound/core/seq/seq_clientmgr.c:1324
    [<ffffffff83d20e5e>] snd_seq_ioctl+0x13e/0x290 sound/core/seq/seq_clientmgr.c:2327
    [<ffffffff81685173>] vfs_ioctl fs/ioctl.c:51 [inline]
    [<ffffffff81685173>] __do_sys_ioctl fs/ioctl.c:870 [inline]
    [<ffffffff81685173>] __se_sys_ioctl fs/ioctl.c:856 [inline]
    [<ffffffff81685173>] __x64_sys_ioctl+0x103/0x140 fs/ioctl.c:856
    [<ffffffff84a77ff9>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
    [<ffffffff84a77ff9>] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
    [<ffffffff84c0008b>] entry_SYSCALL_64_after_hwframe+0x63/0xcd



---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the bug is already fixed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to change bug's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the bug is a duplicate of another bug, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup