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Re: [Qemu-devel] [PATCH] 9pfs: use g_malloc0 to allocate space for xattr
From: |
Greg Kurz |
Subject: |
Re: [Qemu-devel] [PATCH] 9pfs: use g_malloc0 to allocate space for xattr |
Date: |
Wed, 4 Oct 2017 14:26:34 +0200 |
On Wed, 4 Oct 2017 17:06:52 +0530
P J P <address@hidden> wrote:
> From: Prasad J Pandit <address@hidden>
>
> 9p back-end first queries the size of an extended attribute,
> allocates space for it via g_malloc() and then retrieves its
> value into allocated buffer. Race between querying attribute
> size and retrieving its could lead to memory bytes disclosure.
> Use g_malloc0() to avoid it.
>
Applied to 9p-next.
Thanks.
> Reported-by: Tuomas Tynkkynen <address@hidden>
> Signed-off-by: Prasad J Pandit <address@hidden>
> ---
> hw/9pfs/9p.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c
> index 23ac7bb532..f8bbac251d 100644
> --- a/hw/9pfs/9p.c
> +++ b/hw/9pfs/9p.c
> @@ -3234,7 +3234,7 @@ static void coroutine_fn v9fs_xattrwalk(void *opaque)
> xattr_fidp->fid_type = P9_FID_XATTR;
> xattr_fidp->fs.xattr.xattrwalk_fid = true;
> if (size) {
> - xattr_fidp->fs.xattr.value = g_malloc(size);
> + xattr_fidp->fs.xattr.value = g_malloc0(size);
> err = v9fs_co_llistxattr(pdu, &xattr_fidp->path,
> xattr_fidp->fs.xattr.value,
> xattr_fidp->fs.xattr.len);
> @@ -3267,7 +3267,7 @@ static void coroutine_fn v9fs_xattrwalk(void *opaque)
> xattr_fidp->fid_type = P9_FID_XATTR;
> xattr_fidp->fs.xattr.xattrwalk_fid = true;
> if (size) {
> - xattr_fidp->fs.xattr.value = g_malloc(size);
> + xattr_fidp->fs.xattr.value = g_malloc0(size);
> err = v9fs_co_lgetxattr(pdu, &xattr_fidp->path,
> &name, xattr_fidp->fs.xattr.value,
> xattr_fidp->fs.xattr.len);