From: Stephen Smalley <sds@tycho.nsa.gov>
To: selinux@tycho.nsa.gov, richard_c_haines@btinternet.com,
jason@perfinion.com
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Subject: [PATCH] libselinux: selinux_restorecon: fix realpath logic
Date: Wed, 5 Oct 2016 10:52:41 -0400 [thread overview]
Message-ID: <1475679161-24493-1-git-send-email-sds@tycho.nsa.gov> (raw)
The realpath logic in selinux_restorecon() was taken from the
Android libselinux fork. However, bionic dirname() and basename()
do not modify their argument and therefore are safe to call on a
const string. POSIX dirname() and basename() can modify their argument.
There is a GNU basename() that does not modify its argument, but not
for dirname().
For portability, create copies of the original pathname for each call
and keep them around until finished using the result.
Fixes "restorecon -r goes up the tree?" bug reported by Jason Zaman.
Reported-by: Jason Zaman <jason@perfinion.com>
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
---
libselinux/src/selinux_restorecon.c | 23 ++++++++++++++++++-----
1 file changed, 18 insertions(+), 5 deletions(-)
diff --git a/libselinux/src/selinux_restorecon.c b/libselinux/src/selinux_restorecon.c
index 0945138..a3f7d83 100644
--- a/libselinux/src/selinux_restorecon.c
+++ b/libselinux/src/selinux_restorecon.c
@@ -797,25 +797,38 @@ int selinux_restorecon(const char *pathname_orig,
* realpath of containing dir, then appending last component name.
*/
if (flags.userealpath) {
- pathbname = basename((char *)pathname_orig);
+ char *basename_cpy = strdup(pathname_orig);
+ if (!basename_cpy)
+ return -1;
+ pathbname = basename(basename_cpy);
if (!strcmp(pathbname, "/") || !strcmp(pathbname, ".") ||
!strcmp(pathbname, "..")) {
pathname = realpath(pathname_orig, NULL);
- if (!pathname)
+ if (!pathname) {
+ free(basename_cpy);
goto realpatherr;
+ }
} else {
- pathdname = dirname((char *)pathname_orig);
+ char *dirname_cpy = strdup(pathname_orig);
+ pathdname = dirname(dirname_cpy);
pathdnamer = realpath(pathdname, NULL);
- if (!pathdnamer)
+ if (!pathdnamer) {
+ free(basename_cpy);
+ free(dirname_cpy);
goto realpatherr;
+ }
if (!strcmp(pathdnamer, "/"))
error = asprintf(&pathname, "/%s", pathbname);
else
error = asprintf(&pathname, "%s/%s",
pathdnamer, pathbname);
- if (error < 0)
+ free(dirname_cpy);
+ if (error < 0) {
+ free(basename_cpy);
goto oom;
+ }
}
+ free(basename_cpy);
} else {
pathname = strdup(pathname_orig);
if (!pathname)
--
2.7.4
reply other threads:[~2016-10-05 14:52 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1475679161-24493-1-git-send-email-sds@tycho.nsa.gov \
--to=sds@tycho.nsa.gov \
--cc=jason@perfinion.com \
--cc=richard_c_haines@btinternet.com \
--cc=selinux@tycho.nsa.gov \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.