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authorTomas Mraz <tmraz@fedoraproject.org>2012-01-24 20:03:28 +0100
committerTomas Mraz <tmraz@fedoraproject.org>2012-01-24 20:03:28 +0100
commitd5a261b8be2035bbf49726eb7ac792ee6d5a22d1 (patch)
tree743d235c45ab45b0a784c48d1f1df04012c0e784 /modules/pam_namespace/pam_namespace.c
parent91e4c3633f34a6590743ee105746308664078073 (diff)
Make / mount as rslave instead of bind mounting polydirs.
* modules/pam_namespace/pam_namespace.c (protect_dir): Drop the always argument. (check_inst_parent): Drop the always argument from protect_dir(). (create_polydir): Likewise. (ns_setup): Likewise and do not mark the polydir with MS_PRIVATE. (setup_namespace): Mark the / with MS_SLAVE|MS_REC. * modules/pam_namespace/pam_namespace.8.xml: Reflect the change in docs.
Diffstat (limited to 'modules/pam_namespace/pam_namespace.c')
-rw-r--r--modules/pam_namespace/pam_namespace.c40
1 files changed, 19 insertions, 21 deletions
diff --git a/modules/pam_namespace/pam_namespace.c b/modules/pam_namespace/pam_namespace.c
index f0bffa15..470f493b 100644
--- a/modules/pam_namespace/pam_namespace.c
+++ b/modules/pam_namespace/pam_namespace.c
@@ -1003,7 +1003,7 @@ static int protect_mount(int dfd, const char *path, struct instance_data *idata)
return 0;
}
-static int protect_dir(const char *path, mode_t mode, int do_mkdir, int always,
+static int protect_dir(const char *path, mode_t mode, int do_mkdir,
struct instance_data *idata)
{
char *p = strdup(path);
@@ -1082,7 +1082,7 @@ static int protect_dir(const char *path, mode_t mode, int do_mkdir, int always,
}
}
- if ((flags & O_NOFOLLOW) || always) {
+ if (flags & O_NOFOLLOW) {
/* we are inside user-owned dir - protect */
if (protect_mount(rv, p, idata) == -1) {
save_errno = errno;
@@ -1124,7 +1124,7 @@ static int check_inst_parent(char *ipath, struct instance_data *idata)
if (trailing_slash)
*trailing_slash = '\0';
- dfd = protect_dir(inst_parent, 0, 1, 0, idata);
+ dfd = protect_dir(inst_parent, 0, 1, idata);
if (dfd == -1 || fstat(dfd, &instpbuf) < 0) {
pam_syslog(idata->pamh, LOG_ERR,
@@ -1259,7 +1259,7 @@ static int create_polydir(struct polydir_s *polyptr,
}
#endif
- rc = protect_dir(dir, mode, 1, idata->flags & PAMNS_MOUNT_PRIVATE, idata);
+ rc = protect_dir(dir, mode, 1, idata);
if (rc == -1) {
pam_syslog(idata->pamh, LOG_ERR,
"Error creating directory %s: %m", dir);
@@ -1447,7 +1447,7 @@ static int ns_setup(struct polydir_s *polyptr,
pam_syslog(idata->pamh, LOG_DEBUG,
"Set namespace for directory %s", polyptr->dir);
- retval = protect_dir(polyptr->dir, 0, 0, idata->flags & PAMNS_MOUNT_PRIVATE, idata);
+ retval = protect_dir(polyptr->dir, 0, 0, idata);
if (retval < 0 && errno != ENOENT) {
pam_syslog(idata->pamh, LOG_ERR, "Polydir %s access error: %m",
@@ -1534,22 +1534,6 @@ static int ns_setup(struct polydir_s *polyptr,
goto error_out;
}
- if (idata->flags & PAMNS_MOUNT_PRIVATE) {
- /*
- * Make the polyinstantiated dir private mount. This depends
- * on making the dir a mount point in the protect_dir call.
- */
- if (mount(polyptr->dir, polyptr->dir, NULL, MS_PRIVATE|MS_REC, NULL) < 0) {
- pam_syslog(idata->pamh, LOG_ERR, "Error making %s a private mount, %m",
- polyptr->dir);
- goto error_out;
- }
- if (idata->flags & PAMNS_DEBUG)
- pam_syslog(idata->pamh, LOG_DEBUG,
- "Polyinstantiated directory %s made as private mount", polyptr->dir);
-
- }
-
/*
* Bind mount instance directory on top of the polyinstantiated
* directory to provide an instance of polyinstantiated directory
@@ -1720,6 +1704,20 @@ static int setup_namespace(struct instance_data *idata, enum unmnt_op unmnt)
"Unable to unshare from parent namespace, %m");
return PAM_SESSION_ERR;
}
+ if (idata->flags & PAMNS_MOUNT_PRIVATE) {
+ /*
+ * Remount / as SLAVE so that nothing mounted in the namespace
+ * shows up in the parent
+ */
+ if (mount("/", "/", NULL, MS_SLAVE | MS_REC , NULL) < 0) {
+ pam_syslog(idata->pamh, LOG_ERR,
+ "Failed to mark / as a slave mount point, %m");
+ return PAM_SESSION_ERR;
+ }
+ if (idata->flags & PAMNS_DEBUG)
+ pam_syslog(idata->pamh, LOG_DEBUG,
+ "The / mount point was marked as slave");
+ }
} else {
del_polydir_list(idata->polydirs_ptr);
return PAM_SUCCESS;