lkml.org 
[lkml]   [2022]   [Oct]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] KVM: x86: Reduce refcount if single_open() fails in kvm_mmu_rmaps_stat_open()
On Fri, Oct 14, 2022 at 03:55:11PM +0800, Hou Wenlong wrote:
> Refcount is increased before calling single_open() in
> kvm_mmu_rmaps_stat_open(), If single_open() fails, refcount should be
> restored, otherwise the vm couldn't be destroyed.
>
> Fixes: 3bcd0662d66fd ("KVM: X86: Introduce mmu_rmaps_stat per-vm debugfs file")
> Signed-off-by: Hou Wenlong <houwenlong.hwl@antgroup.com>
> ---
> arch/x86/kvm/debugfs.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/kvm/debugfs.c b/arch/x86/kvm/debugfs.c
> index cfed36aba2f7..412ed1b341fa 100644
> --- a/arch/x86/kvm/debugfs.c
> +++ b/arch/x86/kvm/debugfs.c
> @@ -162,7 +162,12 @@ static int kvm_mmu_rmaps_stat_open(struct inode *inode, struct file *file)
> if (!kvm_get_kvm_safe(kvm))
> return -ENOENT;
>
> - return single_open(file, kvm_mmu_rmaps_stat_show, kvm);
> + if (single_open(file, kvm_mmu_rmaps_stat_show, kvm)) {
> + kvm_put_kvm(kvm);
> + return -ENOMEM;
> + }

Thanks for fixing this. Would it be nicer to wire the single_open retval
(even though it'll only fail with -ENOMEM with current code base)?

--
Peter Xu

\
 
 \ /
  Last update: 2022-10-14 16:12    [W:0.032 / U:0.112 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site