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authorGravatar Denis Vlasenko <vda.linux@googlemail.com>2007-05-02 23:01:32 +0000
committerGravatar Denis Vlasenko <vda.linux@googlemail.com>2007-05-02 23:01:32 +0000
commit3bc18253b081cc0b73f902036416fea47f2b61e5 (patch)
treec1f857892931a55c1f651b44d8f0c60121ea8e43 /applets
parentf92df58d3d97bb75d7b12437d53dd97acfd01095 (diff)
downloadbusybox-3bc18253b081cc0b73f902036416fea47f2b61e5.tar.gz
busybox-3bc18253b081cc0b73f902036416fea47f2b61e5.tar.bz2
fix suid config handling
Diffstat (limited to 'applets')
-rw-r--r--applets/applets.c39
1 files changed, 25 insertions, 14 deletions
diff --git a/applets/applets.c b/applets/applets.c
index 66bcc42de..32c63d1e0 100644
--- a/applets/applets.c
+++ b/applets/applets.c
@@ -110,9 +110,6 @@ static char *get_trimmed_slice(char *s, char *e)
/* Don't depend on the tools to combine strings. */
static const char config_file[] = "/etc/busybox.conf";
-/* There are 4 chars + 1 nul for each of user/group/other. */
-static const char mode_chars[] = "Ssx-\0Ssx-\0Ttx-";
-
/* We don't supply a value for the nul, so an index adjustment is
* necessary below. Also, we use unsigned short here to save some
* space even though these are really mode_t values. */
@@ -257,6 +254,9 @@ static void parse_config_file(void)
e = skip_whitespace(e+1);
for (i = 0; i < 3; i++) {
+ /* There are 4 chars + 1 nul for each of user/group/other. */
+ static const char mode_chars[] = "Ssx-\0" "Ssx-\0" "Ttx-";
+
const char *q;
q = strchrnul(mode_chars + 5*i, *e++);
if (!*q) {
@@ -337,7 +337,8 @@ static inline void parse_config_file(void)
#if ENABLE_FEATURE_SUID
static void check_suid(const struct bb_applet *applet)
{
- uid_t rgid; /* real gid */
+ uid_t uid;
+ gid_t rgid; /* real gid */
if (ruid == 0) /* set by parse_config_file() */
return; /* run by root - no need to check more */
@@ -368,16 +369,24 @@ static void check_suid(const struct bb_applet *applet)
if (!(m & S_IXOTH)) /* is x bit not set ? */
bb_error_msg_and_die("you have no permission to run this applet!");
- if (sct->m_gid != 0) {
- /* _both_ have to be set for sgid */
- if ((sct->m_mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) {
- xsetgid(sct->m_gid);
- } else xsetgid(rgid); /* no sgid -> drop */
- }
- if (sct->m_uid != 0) {
- if (sct->m_mode & S_ISUID) xsetuid(sct->m_uid);
- else xsetuid(ruid); /* no suid -> drop */
- }
+ /* _both_ sgid and group_exec have to be set for setegid */
+ if ((sct->m_mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP))
+ rgid = sct->m_gid;
+ /* else (no setegid) we will set egid = rgid */
+
+ /* We set effective AND saved ids. If saved-id is not set
+ * like we do below, seteiud(0) can still later succeed! */
+ if (setresgid(-1, rgid, rgid))
+ bb_perror_msg_and_die("setresgid");
+
+ /* do we have to set effective uid? */
+ uid = ruid;
+ if (sct->m_mode & S_ISUID)
+ uid = sct->m_uid;
+ /* else (no seteuid) we will set euid = ruid */
+
+ if (setresuid(-1, uid, uid))
+ bb_perror_msg_and_die("setresuid");
return;
}
#if !ENABLE_FEATURE_SUID_CONFIG_QUIET
@@ -393,6 +402,8 @@ static void check_suid(const struct bb_applet *applet)
#endif
if (applet->need_suid == _BB_SUID_ALWAYS) {
+ /* Real uid is not 0. If euid isn't 0 too, suid bit
+ * is most probably not set on our executable */
if (geteuid())
bb_error_msg_and_die("applet requires root privileges!");
} else if (applet->need_suid == _BB_SUID_NEVER) {