[syzbot] memory leak in kvm_dev_ioctl

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: e058a84b Merge tag 'drm-next-2021-07-01' of git://anongit...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=171fbbdc300000
kernel config: https://syzkaller.appspot.com/x/.config?x=8c46abb9076f44dc
dashboard link: https://syzkaller.appspot.com/bug?extid=c87d2efb740931ec76c7
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=119d1efc300000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16c58c28300000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c87d2e...@syzkaller.appspotmail.com

executing program
BUG: memory leak
unreferenced object 0xffff888101be6180 (size 32):
comm "syz-executor591", pid 8432, jiffies 4294944117 (age 12.420s)
hex dump (first 32 bytes):
00 10 dc 00 00 c9 ff ff 20 ee 80 84 ff ff ff ff ........ .......
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff81043830>] kmalloc include/linux/slab.h:591 [inline]
[<ffffffff81043830>] kzalloc include/linux/slab.h:721 [inline]
[<ffffffff81043830>] kvm_create_vm_debugfs arch/x86/kvm/../../../virt/kvm/kvm_main.c:916 [inline]
[<ffffffff81043830>] kvm_dev_ioctl_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:4471 [inline]
[<ffffffff81043830>] kvm_dev_ioctl+0x710/0xb60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4498
[<ffffffff81588bec>] vfs_ioctl fs/ioctl.c:51 [inline]
[<ffffffff81588bec>] __do_sys_ioctl fs/ioctl.c:1069 [inline]
[<ffffffff81588bec>] __se_sys_ioctl fs/ioctl.c:1055 [inline]
[<ffffffff81588bec>] __x64_sys_ioctl+0xfc/0x140 fs/ioctl.c:1055
[<ffffffff84396e45>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
[<ffffffff84396e45>] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
[<ffffffff84400068>] entry_SYSCALL_64_after_hwframe+0x44/0xae

BUG: memory leak
unreferenced object 0xffff888101c620a0 (size 32):
comm "syz-executor591", pid 8432, jiffies 4294944117 (age 12.420s)
hex dump (first 32 bytes):
00 10 dc 00 00 c9 ff ff e0 ee 80 84 ff ff ff ff ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff81043830>] kmalloc include/linux/slab.h:591 [inline]
[<ffffffff81043830>] kzalloc include/linux/slab.h:721 [inline]
[<ffffffff81043830>] kvm_create_vm_debugfs arch/x86/kvm/../../../virt/kvm/kvm_main.c:916 [inline]
[<ffffffff81043830>] kvm_dev_ioctl_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:4471 [inline]
[<ffffffff81043830>] kvm_dev_ioctl+0x710/0xb60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4498
[<ffffffff81588bec>] vfs_ioctl fs/ioctl.c:51 [inline]
[<ffffffff81588bec>] __do_sys_ioctl fs/ioctl.c:1069 [inline]
[<ffffffff81588bec>] __se_sys_ioctl fs/ioctl.c:1055 [inline]
[<ffffffff81588bec>] __x64_sys_ioctl+0xfc/0x140 fs/ioctl.c:1055
[<ffffffff84396e45>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
[<ffffffff84396e45>] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
[<ffffffff84400068>] entry_SYSCALL_64_after_hwframe+0x44/0xae

BUG: memory leak
unreferenced object 0xffff888101c62360 (size 32):
comm "syz-executor591", pid 8432, jiffies 4294944118 (age 12.410s)
hex dump (first 32 bytes):
00 10 dc 00 00 c9 ff ff 20 ef 80 84 ff ff ff ff ........ .......
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff81043830>] kmalloc include/linux/slab.h:591 [inline]
[<ffffffff81043830>] kzalloc include/linux/slab.h:721 [inline]
[<ffffffff81043830>] kvm_create_vm_debugfs arch/x86/kvm/../../../virt/kvm/kvm_main.c:916 [inline]
[<ffffffff81043830>] kvm_dev_ioctl_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:4471 [inline]
[<ffffffff81043830>] kvm_dev_ioctl+0x710/0xb60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4498
[<ffffffff81588bec>] vfs_ioctl fs/ioctl.c:51 [inline]
[<ffffffff81588bec>] __do_sys_ioctl fs/ioctl.c:1069 [inline]
[<ffffffff81588bec>] __se_sys_ioctl fs/ioctl.c:1055 [inline]
[<ffffffff81588bec>] __x64_sys_ioctl+0xfc/0x140 fs/ioctl.c:1055
[<ffffffff84396e45>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
[<ffffffff84396e45>] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
[<ffffffff84400068>] entry_SYSCALL_64_after_hwframe+0x44/0xae

BUG: memory leak
unreferenced object 0xffff888101c62ba0 (size 32):
comm "syz-executor591", pid 8432, jiffies 4294944118 (age 12.410s)
hex dump (first 32 bytes):
00 10 dc 00 00 c9 ff ff 60 ef 80 84 ff ff ff ff ........`.......
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff81043830>] kmalloc include/linux/slab.h:591 [inline]
[<ffffffff81043830>] kzalloc include/linux/slab.h:721 [inline]
[<ffffffff81043830>] kvm_create_vm_debugfs arch/x86/kvm/../../../virt/kvm/kvm_main.c:916 [inline]
[<ffffffff81043830>] kvm_dev_ioctl_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:4471 [inline]
[<ffffffff81043830>] kvm_dev_ioctl+0x710/0xb60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4498
[<ffffffff81588bec>] vfs_ioctl fs/ioctl.c:51 [inline]
[<ffffffff81588bec>] __do_sys_ioctl fs/ioctl.c:1069 [inline]
[<ffffffff81588bec>] __se_sys_ioctl fs/ioctl.c:1055 [inline]
[<ffffffff81588bec>] __x64_sys_ioctl+0xfc/0x140 fs/ioctl.c:1055
[<ffffffff84396e45>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
[<ffffffff84396e45>] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
[<ffffffff84400068>] entry_SYSCALL_64_after_hwframe+0x44/0xae

BUG: memory leak
unreferenced object 0xffff888101c62b20 (size 32):
comm "syz-executor591", pid 8432, jiffies 4294944118 (age 12.410s)
hex dump (first 32 bytes):
00 10 dc 00 00 c9 ff ff a0 ef 80 84 ff ff ff ff ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff81043830>] kmalloc include/linux/slab.h:591 [inline]
[<ffffffff81043830>] kzalloc include/linux/slab.h:721 [inline]
[<ffffffff81043830>] kvm_create_vm_debugfs arch/x86/kvm/../../../virt/kvm/kvm_main.c:916 [inline]
[<ffffffff81043830>] kvm_dev_ioctl_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:4471 [inline]
[<ffffffff81043830>] kvm_dev_ioctl+0x710/0xb60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4498
[<ffffffff81588bec>] vfs_ioctl fs/ioctl.c:51 [inline]
[<ffffffff81588bec>] __do_sys_ioctl fs/ioctl.c:1069 [inline]
[<ffffffff81588bec>] __se_sys_ioctl fs/ioctl.c:1055 [inline]
[<ffffffff81588bec>] __x64_sys_ioctl+0xfc/0x140 fs/ioctl.c:1055
[<ffffffff84396e45>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
[<ffffffff84396e45>] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
[<ffffffff84400068>] entry_SYSCALL_64_after_hwframe+0x44/0xae

BUG: memory leak
unreferenced object 0xffff888101c62660 (size 32):
comm "syz-executor591", pid 8432, jiffies 4294944118 (age 12.410s)
hex dump (first 32 bytes):
00 10 dc 00 00 c9 ff ff e0 ef 80 84 ff ff ff ff ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff81043830>] kmalloc include/linux/slab.h:591 [inline]
[<ffffffff81043830>] kzalloc include/linux/slab.h:721 [inline]
[<ffffffff81043830>] kvm_create_vm_debugfs arch/x86/kvm/../../../virt/kvm/kvm_main.c:916 [inline]
[<ffffffff81043830>] kvm_dev_ioctl_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:4471 [inline]
[<ffffffff81043830>] kvm_dev_ioctl+0x710/0xb60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4498
[<ffffffff81588bec>] vfs_ioctl fs/ioctl.c:51 [inline]
[<ffffffff81588bec>] __do_sys_ioctl fs/ioctl.c:1069 [inline]
[<ffffffff81588bec>] __se_sys_ioctl fs/ioctl.c:1055 [inline]
[<ffffffff81588bec>] __x64_sys_ioctl+0xfc/0x140 fs/ioctl.c:1055
[<ffffffff84396e45>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
[<ffffffff84396e45>] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
[<ffffffff84400068>] entry_SYSCALL_64_after_hwframe+0x44/0xae

BUG: memory leak
unreferenced object 0xffff888101c62460 (size 32):
comm "syz-executor591", pid 8432, jiffies 4294944118 (age 12.410s)
hex dump (first 32 bytes):
00 10 dc 00 00 c9 ff ff 20 f0 80 84 ff ff ff ff ........ .......
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff81043830>] kmalloc include/linux/slab.h:591 [inline]
[<ffffffff81043830>] kzalloc include/linux/slab.h:721 [inline]
[<ffffffff81043830>] kvm_create_vm_debugfs arch/x86/kvm/../../../virt/kvm/kvm_main.c:916 [inline]
[<ffffffff81043830>] kvm_dev_ioctl_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:4471 [inline]
[<ffffffff81043830>] kvm_dev_ioctl+0x710/0xb60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4498
[<ffffffff81588bec>] vfs_ioctl fs/ioctl.c:51 [inline]
[<ffffffff81588bec>] __do_sys_ioctl fs/ioctl.c:1069 [inline]
[<ffffffff81588bec>] __se_sys_ioctl fs/ioctl.c:1055 [inline]
[<ffffffff81588bec>] __x64_sys_ioctl+0xfc/0x140 fs/ioctl.c:1055
[<ffffffff84396e45>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
[<ffffffff84396e45>] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
[<ffffffff84400068>] entry_SYSCALL_64_after_hwframe+0x44/0xae



---
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[Pavel Skripkin]

On Fri, 02 Jul 2021 23:05:26 -0700
syzbot <syzbot+c87d2e...@syzkaller.appspotmail.com> wrote:

> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: e058a84b Merge tag 'drm-next-2021-07-01' of
> git://anongit... git tree: upstream
> console output:
> https://syzkaller.appspot.com/x/log.txt?x=171fbbdc300000 kernel
> config: https://syzkaller.appspot.com/x/.config?x=8c46abb9076f44dc
> dashboard link:
> https://syzkaller.appspot.com/bug?extid=c87d2efb740931ec76c7 syz
> repro:
> https://syzkaller.appspot.com/x/repro.syz?x=119d1efc300000 C
> reproducer: https://syzkaller.appspot.com/x/repro.c?x=16c58c28300000
>
> IMPORTANT: if you fix the issue, please add the following tag to the
> commit: Reported-by:
> syzbot+c87d2e...@syzkaller.appspotmail.com
>

Corresponding fix was sent about 2 days ago
https://patchwork.kernel.org/project/kvm/patch/20210701195500.2...@gmail.com/



With regards,
Pavel Skripkin

[Dmitry Vyukov]

Hi Pavel,

Thanks for checking. Let's tell syzbot about the fix:

#syz fix: kvm: debugfs: fix memory leak in kvm_create_vm_debugfs

[Pavel Skripkin]

Hi, Dmitry!

Sorry for stupid question :)

I don't see, that my patch was applied, so syzbot will save the patch
name and will test it after it will be applied? I thought about
sending `syz fix` command, but I was sure that syzbot takes only
accepted patches.



With regards,
Pavel Skripkin

[Dmitry Vyukov]

Hi Pavel,

Please see if http://bit.do/syzbot#communication-with-syzbot answers
your questions.

[Pavel Skripkin]

On Mon, 5 Jul 2021 13:47:30 +0200

Yes, it does. Thank you!


With regards,
Pavel Skripkin