[v3,BZ,#17273] fix incorrect mount table entry parsing in __getmntent_r()
Commit Message
When mount entry contains only four fields and have more
then one space or tab at the and, mp.mnt_freq and
mp.mnt_passno will be set to some specific values as side
effect from parsing of previus mount entry. It is because
sscanf(""," %d %d ", &a, &b) returns -1, but this case
is unprocessed. Values of mp.mnt_freq and mp.mnt_passno
stays unchanged. This patch is attempt to fix described issue
by removing trailing tabs and spaces.
[BZ #17273]
* misc/mntent_r.c (__getmntent_r): Cut off trailing spaces
and tabs from buffer before parsing fstab entry.
* misc/tst-mntent.c (main): Add test for mount entry with
trailing spaces and tabs.
---
misc/mntent_r.c | 6 +++++-
misc/tst-mntent.c | 22 +++++++++++++++++++++-
2 files changed, 26 insertions(+), 2 deletions(-)
Comments
On Tue, Dec 9, 2014 at 4:41 AM, Vladimir A. Nazarenko <naszar@ya.ru> wrote:
> When mount entry contains only four fields and have more
> then one space or tab at the and, mp.mnt_freq and
> mp.mnt_passno will be set to some specific values as side
> effect from parsing of previus mount entry. It is because
> sscanf(""," %d %d ", &a, &b) returns -1, but this case
> is unprocessed. Values of mp.mnt_freq and mp.mnt_passno
> stays unchanged. This patch is attempt to fix described issue
> by removing trailing tabs and spaces.
>
> [BZ #17273]
> * misc/mntent_r.c (__getmntent_r): Cut off trailing spaces
> and tabs from buffer before parsing fstab entry.
> * misc/tst-mntent.c (main): Add test for mount entry with
> trailing spaces and tabs.
> ---
> misc/mntent_r.c | 6 +++++-
> misc/tst-mntent.c | 22 +++++++++++++++++++++-
> 2 files changed, 26 insertions(+), 2 deletions(-)
>
> diff --git a/misc/mntent_r.c b/misc/mntent_r.c
> index e68ec8e..e0a0b9d 100644
> --- a/misc/mntent_r.c
> +++ b/misc/mntent_r.c
> @@ -135,7 +135,11 @@ __getmntent_r (FILE *stream, struct mntent *mp, char *buffer, int bufsiz)
>
> end_ptr = strchr (buffer, '\n');
> if (end_ptr != NULL) /* chop newline */
> - *end_ptr = '\0';
> + {
> + while (end_ptr[-1] == ' ' || end_ptr[-1] == '\t')
> + end_ptr--;
> + *end_ptr = '\0';
> + }
> else
> {
> /* Not the whole line was read. Do it now but forget it. */
> diff --git a/misc/tst-mntent.c b/misc/tst-mntent.c
> index 802b56e..876c89f 100644
> --- a/misc/tst-mntent.c
> +++ b/misc/tst-mntent.c
> @@ -73,7 +73,27 @@ main (int argc, char *argv[])
> puts ("Error while reading written entry back in");
> result = 1;
> }
> - }
> +
> + /* Part III: Entry with whitespaces at the end of a line. */
> + rewind (fp);
> +
> + fputs ("/foo\\040dir /bar\\040dir auto bind \t \n", fp);
> +
> + rewind (fp);
> +
> + mnt = getmntent (fp);
> +
> + if (strcmp (mnt->mnt_fsname, "/foo dir") != 0
> + || strcmp (mnt->mnt_dir, "/bar dir") != 0
> + || strcmp (mnt->mnt_type, "auto") != 0
> + || strcmp (mnt->mnt_opts, "bind") != 0
> + || mnt->mnt_freq != 0
> + || mnt->mnt_passno != 0)
> + {
> + puts ("Error while reading entry with trailing whitespaces");
> + result = 1;
> + }
> + }
>
> return result;
> }
> --
> 2.1.1
>
Has the copyright assignment issue been resolved?
On 07.01.2015 03:11, H.J. Lu wrote:
>
> Has the copyright assignment issue been resolved?
>
Yes, I think so. I received signed paper from FSF. Should I send it to someone?
On Wed, 7 Jan 2015, Vladimir A. Nazarenko wrote:
> On 07.01.2015 03:11, H.J. Lu wrote:
> >
> > Has the copyright assignment issue been resolved?
> >
>
> Yes, I think so. I received signed paper from FSF. Should I send it to
> someone?
I can confirm there is a copyright.list entry for Vladimir A. Nazarenko
dated 2014-11-24, so no further action is needed there.
@@ -135,7 +135,11 @@ __getmntent_r (FILE *stream, struct mntent *mp, char *buffer, int bufsiz)
end_ptr = strchr (buffer, '\n');
if (end_ptr != NULL) /* chop newline */
- *end_ptr = '\0';
+ {
+ while (end_ptr[-1] == ' ' || end_ptr[-1] == '\t')
+ end_ptr--;
+ *end_ptr = '\0';
+ }
else
{
/* Not the whole line was read. Do it now but forget it. */
@@ -73,7 +73,27 @@ main (int argc, char *argv[])
puts ("Error while reading written entry back in");
result = 1;
}
- }
+
+ /* Part III: Entry with whitespaces at the end of a line. */
+ rewind (fp);
+
+ fputs ("/foo\\040dir /bar\\040dir auto bind \t \n", fp);
+
+ rewind (fp);
+
+ mnt = getmntent (fp);
+
+ if (strcmp (mnt->mnt_fsname, "/foo dir") != 0
+ || strcmp (mnt->mnt_dir, "/bar dir") != 0
+ || strcmp (mnt->mnt_type, "auto") != 0
+ || strcmp (mnt->mnt_opts, "bind") != 0
+ || mnt->mnt_freq != 0
+ || mnt->mnt_passno != 0)
+ {
+ puts ("Error while reading entry with trailing whitespaces");
+ result = 1;
+ }
+ }
return result;
}