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authorDamien Miller <djm@mindrot.org>2014-04-01 14:38:07 +1100
committerDamien Miller <djm@mindrot.org>2014-04-01 14:38:07 +1100
commit14928b7492abec82afa4c2b778fc03f78cd419b6 (patch)
treebed8b997bd4afbd236e25ee415d94f2cfe42f576 /sftp-server.c
parent48abc47e60048461fe9117e108a7e99ea1ac2bb8 (diff)
- (djm) On platforms that support it, use prctl() to prevent sftp-server
from accessing /proc/self/{mem,maps}; patch from jann AT thejh.net
Diffstat (limited to 'sftp-server.c')
-rw-r--r--sftp-server.c14
1 files changed, 14 insertions, 0 deletions
diff --git a/sftp-server.c b/sftp-server.c
index b8eb59c3..77834117 100644
--- a/sftp-server.c
+++ b/sftp-server.c
@@ -29,6 +29,9 @@
#ifdef HAVE_SYS_STATVFS_H
#include <sys/statvfs.h>
#endif
+#ifdef HAVE_SYS_PRCTL_H
+#include <sys/prctl.h>
+#endif
#include <dirent.h>
#include <errno.h>
@@ -1523,6 +1526,17 @@ sftp_server_main(int argc, char **argv, struct passwd *user_pw)
log_init(__progname, log_level, log_facility, log_stderr);
+#ifdef HAVE_PRCTL
+ /*
+ * On Linux, we should try to avoid making /proc/self/{mem,maps}
+ * available to the user so that sftp access doesn't automatically
+ * imply arbitrary code execution access that will break
+ * restricted configurations.
+ */
+ if (prctl(PR_SET_DUMPABLE, 0) != 0)
+ fatal("unable to make the process undumpable");
+#endif
+
if ((cp = getenv("SSH_CONNECTION")) != NULL) {
client_addr = xstrdup(cp);
if ((cp = strchr(client_addr, ' ')) == NULL) {