[PATCH] cifs: use the correct max-length for dentry_path_raw()

[PATCH] cifs: use the correct max-length for dentry_path_raw()

[Ronnie Sahlberg]

RHBZ: 1972502

PATH_MAX is 4096 but PAGE_SIZE can be >4096 on some architectures
such as ppc and would thus write beyond the end of the actual object.

CC: Stable <stable@vger.kernel.org>
Suggested-by: Brian foster <bfoster@redhat.com>
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
---
 fs/cifs/dir.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index 79402ca0ddfa..5f8a302ffcb2 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -100,7 +100,7 @@ build_path_from_dentry_optional_prefix(struct dentry *direntry, void *page,
 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH)
 		pplen = cifs_sb->prepath ? strlen(cifs_sb->prepath) + 1 : 0;
 
-	s = dentry_path_raw(direntry, page, PAGE_SIZE);
+	s = dentry_path_raw(direntry, page, PATH_MAX);
 	if (IS_ERR(s))
 		return s;
 	if (!s[1])	// for root we want "", not "/"
-- 
2.30.2

Re: [PATCH] cifs: use the correct max-length for dentry_path_raw()

[Steve French]

tentatively merged into cifs-2.6.git for-next pending testing

http://smb3-test-rhel-75.southcentralus.cloudapp.azure.com/#/builders/2/builds/765

On Mon, Aug 9, 2021 at 9:36 PM Ronnie Sahlberg <lsahlber@redhat.com> wrote:
>
> RHBZ: 1972502
>
> PATH_MAX is 4096 but PAGE_SIZE can be >4096 on some architectures
> such as ppc and would thus write beyond the end of the actual object.
>
> CC: Stable <stable@vger.kernel.org>
> Suggested-by: Brian foster <bfoster@redhat.com>
> Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
> ---
>  fs/cifs/dir.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
> index 79402ca0ddfa..5f8a302ffcb2 100644
> --- a/fs/cifs/dir.c
> +++ b/fs/cifs/dir.c
> @@ -100,7 +100,7 @@ build_path_from_dentry_optional_prefix(struct dentry *direntry, void *page,
>         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH)
>                 pplen = cifs_sb->prepath ? strlen(cifs_sb->prepath) + 1 : 0;
>
> -       s = dentry_path_raw(direntry, page, PAGE_SIZE);
> +       s = dentry_path_raw(direntry, page, PATH_MAX);
>         if (IS_ERR(s))
>                 return s;
>         if (!s[1])      // for root we want "", not "/"
> --
> 2.30.2
>


-- 
Thanks,

Steve

[PATCH] cifs: use the correct max-length for dentry_path_raw()

[Ronnie Sahlberg]

RHBZ: 1972502

PATH_MAX is 4096 but PAGE_SIZE can be >4096 on some architectures
such as ppc and would thus write beyond the end of the actual object.

CC: Stable <stable@vger.kernel.org>
Reported-by: Xiaoli Feng <xifeng@redhat.com>
Suggested-by: Brian foster <bfoster@redhat.com>
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
---
 fs/cifs/dir.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index 79402ca0ddfa..5f8a302ffcb2 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -100,7 +100,7 @@ build_path_from_dentry_optional_prefix(struct dentry *direntry, void *page,
 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH)
 		pplen = cifs_sb->prepath ? strlen(cifs_sb->prepath) + 1 : 0;
 
-	s = dentry_path_raw(direntry, page, PAGE_SIZE);
+	s = dentry_path_raw(direntry, page, PATH_MAX);
 	if (IS_ERR(s))
 		return s;
 	if (!s[1])	// for root we want "", not "/"
-- 
2.30.2

Re: [PATCH] cifs: use the correct max-length for dentry_path_raw()

[Paulo Alcantara]

Ronnie Sahlberg <lsahlber@redhat.com> writes:

> RHBZ: 1972502
>
> PATH_MAX is 4096 but PAGE_SIZE can be >4096 on some architectures
> such as ppc and would thus write beyond the end of the actual object.
>
> CC: Stable <stable@vger.kernel.org>
> Reported-by: Xiaoli Feng <xifeng@redhat.com>
> Suggested-by: Brian foster <bfoster@redhat.com>
> Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
> ---
>  fs/cifs/dir.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>