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authorDenys Vlasenko <vda.linux@googlemail.com>2013-10-06 13:14:25 (GMT)
committer Denys Vlasenko <vda.linux@googlemail.com>2013-10-06 13:14:25 (GMT)
commitcd256e1c407aa70dfefb7178ed2c0e4201f1aaf7 (patch)
treefefa7b99ae531051123281cc5673e0022940de5c
parent3eab2b7675fc7e2889cd69285a2a31980a4bf504 (diff)
downloadbusybox-cd256e1c407aa70dfefb7178ed2c0e4201f1aaf7.tar.gz
busybox-cd256e1c407aa70dfefb7178ed2c0e4201f1aaf7.tar.bz2
wall: access FILE under real user's credentials
While at it, move applet/config/kbuild bits into wall.c. (This way, it's more visible that applet is suid'ed). function old new delta wall_main 87 138 +51 Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
-rw-r--r--include/applets.src.h2
-rw-r--r--miscutils/Config.src7
-rw-r--r--miscutils/Kbuild.src1
-rw-r--r--miscutils/wall.c25
4 files changed, 24 insertions, 11 deletions
diff --git a/include/applets.src.h b/include/applets.src.h
index aa319bb..3a47e15 100644
--- a/include/applets.src.h
+++ b/include/applets.src.h
@@ -407,8 +407,6 @@ IF_VCONFIG(APPLET(vconfig, BB_DIR_SBIN, BB_SUID_DROP))
/* Needs to be run by root or be suid root - needs to change uid and gid: */
IF_VLOCK(APPLET(vlock, BB_DIR_USR_BIN, BB_SUID_REQUIRE))
IF_VOLNAME(APPLET(volname, BB_DIR_USR_BIN, BB_SUID_DROP))
-/* Needs to be run by root or be suid root - needs to write to /dev/TTY: */
-IF_WALL(APPLET(wall, BB_DIR_USR_BIN, BB_SUID_REQUIRE))
IF_WATCH(APPLET(watch, BB_DIR_BIN, BB_SUID_DROP))
IF_WATCHDOG(APPLET(watchdog, BB_DIR_SBIN, BB_SUID_DROP))
IF_WC(APPLET(wc, BB_DIR_USR_BIN, BB_SUID_DROP))
diff --git a/miscutils/Config.src b/miscutils/Config.src
index b9fc196..117ec77 100644
--- a/miscutils/Config.src
+++ b/miscutils/Config.src
@@ -591,13 +591,6 @@ config VOLNAME
help
Prints a CD-ROM volume name.
-config WALL
- bool "wall"
- default y
- depends on FEATURE_UTMP
- help
- Write a message to all users that are logged in.
-
config WATCHDOG
bool "watchdog"
default y
diff --git a/miscutils/Kbuild.src b/miscutils/Kbuild.src
index 8c49864..f3954f4 100644
--- a/miscutils/Kbuild.src
+++ b/miscutils/Kbuild.src
@@ -46,5 +46,4 @@ lib-$(CONFIG_TIME) += time.o
lib-$(CONFIG_TIMEOUT) += timeout.o
lib-$(CONFIG_TTYSIZE) += ttysize.o
lib-$(CONFIG_VOLNAME) += volname.o
-lib-$(CONFIG_WALL) += wall.o
lib-$(CONFIG_WATCHDOG) += watchdog.o
diff --git a/miscutils/wall.c b/miscutils/wall.c
index 762f53b..c74f4f2 100644
--- a/miscutils/wall.c
+++ b/miscutils/wall.c
@@ -6,6 +6,18 @@
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
+//config:config WALL
+//config: bool "wall"
+//config: default y
+//config: depends on FEATURE_UTMP
+//config: help
+//config: Write a message to all users that are logged in.
+
+/* Needs to be run by root or be suid root - needs to write to /dev/TTY: */
+//applet:IF_WALL(APPLET(wall, BB_DIR_USR_BIN, BB_SUID_REQUIRE))
+
+//kbuild:lib-$(CONFIG_WALL) += wall.o
+
//usage:#define wall_trivial_usage
//usage: "[FILE]"
//usage:#define wall_full_usage "\n\n"
@@ -22,8 +34,19 @@ int wall_main(int argc UNUSED_PARAM, char **argv)
{
struct utmp *ut;
char *msg;
- int fd = argv[1] ? xopen(argv[1], O_RDONLY) : STDIN_FILENO;
+ int fd;
+ fd = STDIN_FILENO;
+ if (argv[1]) {
+ /* The applet is setuid.
+ * Access to the file must be under user's uid/gid.
+ */
+ setfsuid(getuid());
+ setfsgid(getgid());
+ fd = xopen(argv[1], O_RDONLY);
+ setfsuid(geteuid());
+ setfsgid(getegid());
+ }
msg = xmalloc_read(fd, NULL);
if (ENABLE_FEATURE_CLEAN_UP && argv[1])
close(fd);