* [PATCH 0/2] Fix chsh when called as root
@ 2019-09-21 18:50 Quentin Rameau
2019-09-21 18:50 ` [PATCH 1/2] lib/pwdutils: add xgetpwuid Quentin Rameau
` (2 more replies)
0 siblings, 3 replies; 5+ messages in thread
From: Quentin Rameau @ 2019-09-21 18:50 UTC (permalink / raw)
To: util-linux
Hello,
Because chsh was using getpwuid/getpwnam, there was an issue with
subsequent call to readline with tilde expansion which would also call
the same function and overwrite the getpwuid/getpwnam internal storage
struct passwd, replacing passed username results.
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH 1/2] lib/pwdutils: add xgetpwuid
2019-09-21 18:50 [PATCH 0/2] Fix chsh when called as root Quentin Rameau
@ 2019-09-21 18:50 ` Quentin Rameau
2019-09-21 18:50 ` [PATCH 2/2] chsh: replace getpw unsafe functions with xgetpw Quentin Rameau
2019-09-26 13:57 ` [PATCH 0/2] Fix chsh when called as root Karel Zak
2 siblings, 0 replies; 5+ messages in thread
From: Quentin Rameau @ 2019-09-21 18:50 UTC (permalink / raw)
To: util-linux; +Cc: Quentin Rameau
---
include/pwdutils.h | 1 +
lib/pwdutils.c | 28 ++++++++++++++++++++++++++++
2 files changed, 29 insertions(+)
diff --git a/include/pwdutils.h b/include/pwdutils.h
index a69dd6b45..bea46e57e 100644
--- a/include/pwdutils.h
+++ b/include/pwdutils.h
@@ -5,6 +5,7 @@
#include <pwd.h>
extern struct passwd *xgetpwnam(const char *username, char **pwdbuf);
+extern struct passwd *xgetpwuid(uid_t uid, char **pwdbuf);
extern char *xgetlogin(void);
#endif /* UTIL_LINUX_PWDUTILS_H */
diff --git a/lib/pwdutils.c b/lib/pwdutils.c
index 25b4daed0..d54458d65 100644
--- a/lib/pwdutils.c
+++ b/lib/pwdutils.c
@@ -36,6 +36,34 @@ failed:
return NULL;
}
+struct passwd *xgetpwuid(uid_t uid, char **pwdbuf)
+{
+ struct passwd *pwd = NULL, *res = NULL;
+ int rc;
+
+ if (!pwdbuf)
+ return NULL;
+
+ *pwdbuf = xmalloc(UL_GETPW_BUFSIZ);
+ pwd = xcalloc(1, sizeof(struct passwd));
+
+ errno = 0;
+ rc = getpwuid_r(uid, pwd, *pwdbuf, UL_GETPW_BUFSIZ, &res);
+ if (rc != 0) {
+ errno = rc;
+ goto failed;
+ }
+ if (!res) {
+ errno = EINVAL;
+ goto failed;
+ }
+ return pwd;
+failed:
+ free(pwd);
+ free(*pwdbuf);
+ return NULL;
+}
+
char *xgetlogin(void)
{
struct passwd *pw = NULL;
--
2.21.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH 2/2] chsh: replace getpw unsafe functions with xgetpw
2019-09-21 18:50 [PATCH 0/2] Fix chsh when called as root Quentin Rameau
2019-09-21 18:50 ` [PATCH 1/2] lib/pwdutils: add xgetpwuid Quentin Rameau
@ 2019-09-21 18:50 ` Quentin Rameau
2019-09-26 13:57 ` [PATCH 0/2] Fix chsh when called as root Karel Zak
2 siblings, 0 replies; 5+ messages in thread
From: Quentin Rameau @ 2019-09-21 18:50 UTC (permalink / raw)
To: util-linux; +Cc: Quentin Rameau
---
login-utils/chsh.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/login-utils/chsh.c b/login-utils/chsh.c
index 9b2761157..a9ebec86f 100644
--- a/login-utils/chsh.c
+++ b/login-utils/chsh.c
@@ -38,6 +38,7 @@
#include "islocal.h"
#include "nls.h"
#include "pathnames.h"
+#include "pwdutils.h"
#include "setpwnam.h"
#include "strutils.h"
#include "xalloc.h"
@@ -253,7 +254,7 @@ static void check_shell(const char *shell)
int main(int argc, char **argv)
{
- char *oldshell;
+ char *oldshell, *pwbuf;
int nullshell = 0;
const uid_t uid = getuid();
struct sinfo info = { NULL };
@@ -267,12 +268,12 @@ int main(int argc, char **argv)
parse_argv(argc, argv, &info);
if (!info.username) {
- pw = getpwuid(uid);
+ pw = xgetpwuid(uid, &pwbuf);
if (!pw)
errx(EXIT_FAILURE, _("you (user %d) don't exist."),
uid);
} else {
- pw = getpwnam(info.username);
+ pw = xgetpwnam(info.username, &pwbuf);
if (!pw)
errx(EXIT_FAILURE, _("user \"%s\" does not exist."),
info.username);
--
2.21.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH 0/2] Fix chsh when called as root
2019-09-21 18:50 [PATCH 0/2] Fix chsh when called as root Quentin Rameau
2019-09-21 18:50 ` [PATCH 1/2] lib/pwdutils: add xgetpwuid Quentin Rameau
2019-09-21 18:50 ` [PATCH 2/2] chsh: replace getpw unsafe functions with xgetpw Quentin Rameau
@ 2019-09-26 13:57 ` Karel Zak
2019-09-26 21:34 ` Quentin Rameau
2 siblings, 1 reply; 5+ messages in thread
From: Karel Zak @ 2019-09-26 13:57 UTC (permalink / raw)
To: Quentin Rameau; +Cc: util-linux
On Sat, Sep 21, 2019 at 08:50:19PM +0200, Quentin Rameau wrote:
> Because chsh was using getpwuid/getpwnam, there was an issue with
> subsequent call to readline with tilde expansion which would also call
> the same function and overwrite the getpwuid/getpwnam internal storage
> struct passwd, replacing passed username results.
Applied, thanks.
Karel
--
Karel Zak <kzak@redhat.com>
http://karelzak.blogspot.com
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH 0/2] Fix chsh when called as root
2019-09-26 13:57 ` [PATCH 0/2] Fix chsh when called as root Karel Zak
@ 2019-09-26 21:34 ` Quentin Rameau
0 siblings, 0 replies; 5+ messages in thread
From: Quentin Rameau @ 2019-09-26 21:34 UTC (permalink / raw)
To: util-linux
> > Because chsh was using getpwuid/getpwnam, there was an issue with
> > subsequent call to readline with tilde expansion which would also call
> > the same function and overwrite the getpwuid/getpwnam internal storage
> > struct passwd, replacing passed username results.
>
> Applied, thanks.
Thank you!
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2019-09-26 21:35 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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2019-09-21 18:50 [PATCH 0/2] Fix chsh when called as root Quentin Rameau
2019-09-21 18:50 ` [PATCH 1/2] lib/pwdutils: add xgetpwuid Quentin Rameau
2019-09-21 18:50 ` [PATCH 2/2] chsh: replace getpw unsafe functions with xgetpw Quentin Rameau
2019-09-26 13:57 ` [PATCH 0/2] Fix chsh when called as root Karel Zak
2019-09-26 21:34 ` Quentin Rameau
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