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authorLennart Poettering <lennart@poettering.net>2012-10-03 15:37:44 (GMT)
committer Lennart Poettering <lennart@poettering.net>2012-10-03 15:55:38 (GMT)
commit1dfa7e79a60de680086b1d93fcc3629b463f58bd (patch) (side-by-side diff)
tree288401e1a12f4bf633ae7725e7cb0d09201768e2
parent08f9588885c5d65694b324846b0ed19211d2c178 (diff)
downloadsystemd-1dfa7e79a60de680086b1d93fcc3629b463f58bd.zip
systemd-1dfa7e79a60de680086b1d93fcc3629b463f58bd.tar.gz
journald: only accept fds from certain directories
Diffstat (more/less context) (ignore whitespace changes)
-rw-r--r--src/journal/journald-native.c37
-rw-r--r--src/journal/test-journal-send.c10
2 files changed, 44 insertions, 3 deletions
diff --git a/src/journal/journald-native.c b/src/journal/journald-native.c
index 85458b5..12fb980 100644
--- a/src/journal/journald-native.c
+++ b/src/journal/journald-native.c
@@ -24,6 +24,7 @@
#include <sys/epoll.h>
#include "socket-util.h"
+#include "path-util.h"
#include "journald.h"
#include "journald-native.h"
#include "journald-kmsg.h"
@@ -281,12 +282,44 @@ void server_process_native_file(
const char *label, size_t label_len) {
struct stat st;
- void *p;
+ _cleanup_free_ void *p = NULL;
ssize_t n;
+ int r;
assert(s);
assert(fd >= 0);
+ if (!ucred || ucred->uid != 0) {
+ _cleanup_free_ char *sl = NULL, *k = NULL;
+ const char *e;
+
+ if (asprintf(&sl, "/proc/self/fd/%i", fd) < 0) {
+ log_oom();
+ return;
+ }
+
+ r = readlink_malloc(sl, &k);
+ if (r < 0) {
+ log_error("readlink(%s) failed: %m", sl);
+ return;
+ }
+
+ e = path_startswith(k, "/dev/shm/");
+ if (!e)
+ e = path_startswith(k, "/tmp/");
+ if (!e)
+ e = path_startswith(k, "/var/tmp/");
+ if (!e) {
+ log_error("Received file outside of allowed directories. Refusing.");
+ return;
+ }
+
+ if (strchr(e, '/')) {
+ log_error("Received file in subdirectory of allowed directories. Refusing.");
+ return;
+ }
+ }
+
/* Data is in the passed file, since it didn't fit in a
* datagram. We can't map the file here, since clients might
* then truncate it and trigger a SIGBUS for us. So let's
@@ -321,8 +354,6 @@ void server_process_native_file(
log_error("Failed to read file, ignoring: %s", strerror(-n));
else if (n > 0)
server_process_native_message(s, p, n, ucred, tv, label, label_len);
-
- free(p);
}
int server_open_native_socket(Server*s) {
diff --git a/src/journal/test-journal-send.c b/src/journal/test-journal-send.c
index e708fa4..168c843 100644
--- a/src/journal/test-journal-send.c
+++ b/src/journal/test-journal-send.c
@@ -24,6 +24,8 @@
#include "log.h"
int main(int argc, char *argv[]) {
+ char huge[4096*1024];
+
log_set_max_level(LOG_DEBUG);
sd_journal_print(LOG_INFO, "piepapo");
@@ -37,5 +39,13 @@ int main(int argc, char *argv[]) {
sd_journal_perror("");
+ memset(huge, 'x', sizeof(huge));
+ memcpy(huge, "HUGE=", 5);
+ char_array_0(huge);
+
+ sd_journal_send("MESSAGE=Huge field attached",
+ huge,
+ NULL);
+
return 0;
}