svn commit: r325874 - releng/10.4/sys/kern
Gordon Tetlow
gordon at FreeBSD.org
Wed Nov 15 22:45:52 UTC 2017
Author: gordon
Date: Wed Nov 15 22:45:50 2017
New Revision: 325874
URL: https://svnweb.freebsd.org/changeset/base/325874
Log:
Fix namespace issue in POSIX shm implementation for jails. [SA-17:09]
Approved by: so
Security: FreeBSD-SA-17:09.shm
Security: CVE-2017-1087
Modified:
releng/10.4/sys/kern/uipc_mqueue.c
releng/10.4/sys/kern/uipc_sem.c
releng/10.4/sys/kern/uipc_shm.c
Modified: releng/10.4/sys/kern/uipc_mqueue.c
==============================================================================
--- releng/10.4/sys/kern/uipc_mqueue.c Wed Nov 15 22:45:13 2017 (r325873)
+++ releng/10.4/sys/kern/uipc_mqueue.c Wed Nov 15 22:45:50 2017 (r325874)
@@ -52,6 +52,7 @@ __FBSDID("$FreeBSD$");
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/limits.h>
+#include <sys/malloc.h>
#include <sys/buf.h>
#include <sys/capsicum.h>
#include <sys/dirent.h>
@@ -60,8 +61,8 @@ __FBSDID("$FreeBSD$");
#include <sys/fcntl.h>
#include <sys/file.h>
#include <sys/filedesc.h>
+#include <sys/jail.h>
#include <sys/lock.h>
-#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/mount.h>
#include <sys/mqueue.h>
@@ -131,6 +132,7 @@ struct mqfs_node {
LIST_HEAD(,mqfs_node) mn_children;
LIST_ENTRY(mqfs_node) mn_sibling;
LIST_HEAD(,mqfs_vdata) mn_vnodes;
+ const void *mn_pr_root;
int mn_refcount;
mqfs_type_t mn_type;
int mn_deleted;
@@ -218,6 +220,7 @@ static uma_zone_t mvdata_zone;
static uma_zone_t mqnoti_zone;
static struct vop_vector mqfs_vnodeops;
static struct fileops mqueueops;
+static unsigned mqfs_osd_jail_slot;
/*
* Directory structure construction and manipulation
@@ -235,6 +238,7 @@ static int mqfs_destroy(struct mqfs_node *mn);
static void mqfs_fileno_alloc(struct mqfs_info *mi, struct mqfs_node *mn);
static void mqfs_fileno_free(struct mqfs_info *mi, struct mqfs_node *mn);
static int mqfs_allocv(struct mount *mp, struct vnode **vpp, struct mqfs_node *pn);
+static int mqfs_prison_remove(void *obj, void *data);
/*
* Message queue construction and maniplation
@@ -435,6 +439,7 @@ mqfs_create_node(const char *name, int namelen, struct
node = mqnode_alloc();
strncpy(node->mn_name, name, namelen);
+ node->mn_pr_root = cred->cr_prison->pr_root;
node->mn_type = nodetype;
node->mn_refcount = 1;
vfs_timestamp(&node->mn_birth);
@@ -643,6 +648,9 @@ mqfs_init(struct vfsconf *vfc)
{
struct mqfs_node *root;
struct mqfs_info *mi;
+ osd_method_t methods[PR_MAXMETHOD] = {
+ [PR_METHOD_REMOVE] = mqfs_prison_remove,
+ };
mqnode_zone = uma_zcreate("mqnode", sizeof(struct mqfs_node),
NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
@@ -669,6 +677,7 @@ mqfs_init(struct vfsconf *vfc)
EVENTHANDLER_PRI_ANY);
mq_fdclose = mqueue_fdclose;
p31b_setcfg(CTL_P1003_1B_MESSAGE_PASSING, _POSIX_MESSAGE_PASSING);
+ mqfs_osd_jail_slot = osd_jail_register(NULL, methods);
return (0);
}
@@ -682,6 +691,7 @@ mqfs_uninit(struct vfsconf *vfc)
if (!unloadable)
return (EOPNOTSUPP);
+ osd_jail_deregister(mqfs_osd_jail_slot);
EVENTHANDLER_DEREGISTER(process_exit, exit_tag);
mi = &mqfs_data;
mqfs_destroy(mi->mi_root);
@@ -801,13 +811,17 @@ found:
* Search a directory entry
*/
static struct mqfs_node *
-mqfs_search(struct mqfs_node *pd, const char *name, int len)
+mqfs_search(struct mqfs_node *pd, const char *name, int len, struct ucred *cred)
{
struct mqfs_node *pn;
+ const void *pr_root;
sx_assert(&pd->mn_info->mi_lock, SX_LOCKED);
+ pr_root = cred->cr_prison->pr_root;
LIST_FOREACH(pn, &pd->mn_children, mn_sibling) {
- if (strncmp(pn->mn_name, name, len) == 0 &&
+ /* Only match names within the same prison root directory */
+ if ((pn->mn_pr_root == NULL || pn->mn_pr_root == pr_root) &&
+ strncmp(pn->mn_name, name, len) == 0 &&
pn->mn_name[len] == '\0')
return (pn);
}
@@ -879,7 +893,7 @@ mqfs_lookupx(struct vop_cachedlookup_args *ap)
/* named node */
sx_xlock(&mqfs->mi_lock);
- pn = mqfs_search(pd, pname, namelen);
+ pn = mqfs_search(pd, pname, namelen, cnp->cn_cred);
if (pn != NULL)
mqnode_addref(pn);
sx_xunlock(&mqfs->mi_lock);
@@ -1364,6 +1378,7 @@ mqfs_readdir(struct vop_readdir_args *ap)
struct mqfs_node *pn;
struct dirent entry;
struct uio *uio;
+ const void *pr_root;
int *tmp_ncookies = NULL;
off_t offset;
int error, i;
@@ -1388,10 +1403,18 @@ mqfs_readdir(struct vop_readdir_args *ap)
error = 0;
offset = 0;
+ pr_root = ap->a_cred->cr_prison->pr_root;
sx_xlock(&mi->mi_lock);
LIST_FOREACH(pn, &pd->mn_children, mn_sibling) {
entry.d_reclen = sizeof(entry);
+
+ /*
+ * Only show names within the same prison root directory
+ * (or not associated with a prison, e.g. "." and "..").
+ */
+ if (pn->mn_pr_root != NULL && pn->mn_pr_root != pr_root)
+ continue;
if (!pn->mn_fileno)
mqfs_fileno_alloc(mi, pn);
entry.d_fileno = pn->mn_fileno;
@@ -1525,6 +1548,38 @@ mqfs_rmdir(struct vop_rmdir_args *ap)
#endif /* notyet */
/*
+ * See if this prison root is obsolete, and clean up associated queues if it is.
+ */
+static int
+mqfs_prison_remove(void *obj, void *data __unused)
+{
+ const struct prison *pr = obj;
+ const struct prison *tpr;
+ struct mqfs_node *pn, *tpn;
+ int found;
+
+ found = 0;
+ TAILQ_FOREACH(tpr, &allprison, pr_list) {
+ if (tpr->pr_root == pr->pr_root && tpr != pr && tpr->pr_ref > 0)
+ found = 1;
+ }
+ if (!found) {
+ /*
+ * No jails are rooted in this directory anymore,
+ * so no queues should be either.
+ */
+ sx_xlock(&mqfs_data.mi_lock);
+ LIST_FOREACH_SAFE(pn, &mqfs_data.mi_root->mn_children,
+ mn_sibling, tpn) {
+ if (pn->mn_pr_root == pr->pr_root)
+ (void)do_unlink(pn, curthread->td_ucred);
+ }
+ sx_xunlock(&mqfs_data.mi_lock);
+ }
+ return (0);
+}
+
+/*
* Allocate a message queue
*/
static struct mqueue *
@@ -1984,7 +2039,7 @@ kern_kmq_open(struct thread *td, const char *upath, in
return (error);
sx_xlock(&mqfs_data.mi_lock);
- pn = mqfs_search(mqfs_data.mi_root, path + 1, len - 1);
+ pn = mqfs_search(mqfs_data.mi_root, path + 1, len - 1, td->td_ucred);
if (pn == NULL) {
if (!(flags & O_CREAT)) {
error = ENOENT;
@@ -2079,7 +2134,7 @@ sys_kmq_unlink(struct thread *td, struct kmq_unlink_ar
return (EINVAL);
sx_xlock(&mqfs_data.mi_lock);
- pn = mqfs_search(mqfs_data.mi_root, path + 1, len - 1);
+ pn = mqfs_search(mqfs_data.mi_root, path + 1, len - 1, td->td_ucred);
if (pn != NULL)
error = do_unlink(pn, td->td_ucred);
else
Modified: releng/10.4/sys/kern/uipc_sem.c
==============================================================================
--- releng/10.4/sys/kern/uipc_sem.c Wed Nov 15 22:45:13 2017 (r325873)
+++ releng/10.4/sys/kern/uipc_sem.c Wed Nov 15 22:45:50 2017 (r325874)
@@ -44,6 +44,7 @@ __FBSDID("$FreeBSD$");
#include <sys/file.h>
#include <sys/filedesc.h>
#include <sys/fnv_hash.h>
+#include <sys/jail.h>
#include <sys/kernel.h>
#include <sys/ksem.h>
#include <sys/lock.h>
@@ -444,12 +445,24 @@ ksem_remove(char *path, Fnv32_t fnv, struct ucred *ucr
static void
ksem_info_impl(struct ksem *ks, char *path, size_t size, uint32_t *value)
{
+ const char *ks_path, *pr_path;
+ size_t pr_pathlen;
if (ks->ks_path == NULL)
return;
sx_slock(&ksem_dict_lock);
- if (ks->ks_path != NULL)
- strlcpy(path, ks->ks_path, size);
+ ks_path = ks->ks_path;
+ if (ks_path != NULL) {
+ pr_path = curthread->td_ucred->cr_prison->pr_path;
+ if (strcmp(pr_path, "/") != 0) {
+ /* Return the jail-rooted pathname. */
+ pr_pathlen = strlen(pr_path);
+ if (strncmp(ks_path, pr_path, pr_pathlen) == 0 &&
+ ks_path[pr_pathlen] == '/')
+ ks_path += pr_pathlen;
+ }
+ strlcpy(path, ks_path, size);
+ }
if (value != NULL)
*value = ks->ks_value;
sx_sunlock(&ksem_dict_lock);
@@ -493,6 +506,8 @@ ksem_create(struct thread *td, const char *name, semid
struct ksem *ks;
struct file *fp;
char *path;
+ const char *pr_path;
+ size_t pr_pathlen;
Fnv32_t fnv;
int error, fd;
@@ -529,10 +544,16 @@ ksem_create(struct thread *td, const char *name, semid
ks->ks_flags |= KS_ANONYMOUS;
} else {
path = malloc(MAXPATHLEN, M_KSEM, M_WAITOK);
- error = copyinstr(name, path, MAXPATHLEN, NULL);
+ pr_path = td->td_ucred->cr_prison->pr_path;
+ /* Construct a full pathname for jailed callers. */
+ pr_pathlen = strcmp(pr_path, "/") == 0 ? 0
+ : strlcpy(path, pr_path, MAXPATHLEN);
+ error = copyinstr(name, path + pr_pathlen,
+ MAXPATHLEN - pr_pathlen, NULL);
+
/* Require paths to start with a '/' character. */
- if (error == 0 && path[0] != '/')
+ if (error == 0 && path[pr_pathlen] != '/')
error = EINVAL;
if (error) {
fdclose(td, fp, fd);
@@ -668,11 +689,17 @@ int
sys_ksem_unlink(struct thread *td, struct ksem_unlink_args *uap)
{
char *path;
+ const char *pr_path;
+ size_t pr_pathlen;
Fnv32_t fnv;
int error;
path = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
- error = copyinstr(uap->name, path, MAXPATHLEN, NULL);
+ pr_path = td->td_ucred->cr_prison->pr_path;
+ pr_pathlen = strcmp(pr_path, "/") == 0 ? 0
+ : strlcpy(path, pr_path, MAXPATHLEN);
+ error = copyinstr(uap->name, path + pr_pathlen, MAXPATHLEN - pr_pathlen,
+ NULL);
if (error) {
free(path, M_TEMP);
return (error);
Modified: releng/10.4/sys/kern/uipc_shm.c
==============================================================================
--- releng/10.4/sys/kern/uipc_shm.c Wed Nov 15 22:45:13 2017 (r325873)
+++ releng/10.4/sys/kern/uipc_shm.c Wed Nov 15 22:45:50 2017 (r325874)
@@ -57,6 +57,7 @@ __FBSDID("$FreeBSD$");
#include <sys/kernel.h>
#include <sys/uio.h>
#include <sys/signal.h>
+#include <sys/jail.h>
#include <sys/ktrace.h>
#include <sys/lock.h>
#include <sys/malloc.h>
@@ -712,6 +713,8 @@ sys_shm_open(struct thread *td, struct shm_open_args *
struct shmfd *shmfd;
struct file *fp;
char *path;
+ const char *pr_path;
+ size_t pr_pathlen;
Fnv32_t fnv;
mode_t cmode;
int fd, error;
@@ -749,13 +752,19 @@ sys_shm_open(struct thread *td, struct shm_open_args *
shmfd = shm_alloc(td->td_ucred, cmode);
} else {
path = malloc(MAXPATHLEN, M_SHMFD, M_WAITOK);
- error = copyinstr(uap->path, path, MAXPATHLEN, NULL);
+ pr_path = td->td_ucred->cr_prison->pr_path;
+
+ /* Construct a full pathname for jailed callers. */
+ pr_pathlen = strcmp(pr_path, "/") == 0 ? 0
+ : strlcpy(path, pr_path, MAXPATHLEN);
+ error = copyinstr(uap->path, path + pr_pathlen,
+ MAXPATHLEN - pr_pathlen, NULL);
#ifdef KTRACE
if (error == 0 && KTRPOINT(curthread, KTR_NAMEI))
ktrnamei(path);
#endif
/* Require paths to start with a '/' character. */
- if (error == 0 && path[0] != '/')
+ if (error == 0 && path[pr_pathlen] != '/')
error = EINVAL;
if (error) {
fdclose(td, fp, fd);
@@ -842,11 +851,17 @@ int
sys_shm_unlink(struct thread *td, struct shm_unlink_args *uap)
{
char *path;
+ const char *pr_path;
+ size_t pr_pathlen;
Fnv32_t fnv;
int error;
path = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
- error = copyinstr(uap->path, path, MAXPATHLEN, NULL);
+ pr_path = td->td_ucred->cr_prison->pr_path;
+ pr_pathlen = strcmp(pr_path, "/") == 0 ? 0
+ : strlcpy(path, pr_path, MAXPATHLEN);
+ error = copyinstr(uap->path, path + pr_pathlen, MAXPATHLEN - pr_pathlen,
+ NULL);
if (error) {
free(path, M_TEMP);
return (error);
@@ -1053,11 +1068,23 @@ shm_unmap(struct file *fp, void *mem, size_t size)
void
shm_path(struct shmfd *shmfd, char *path, size_t size)
{
+ const char *shm_path, *pr_path;
+ size_t pr_pathlen;
if (shmfd->shm_path == NULL)
return;
sx_slock(&shm_dict_lock);
- if (shmfd->shm_path != NULL)
- strlcpy(path, shmfd->shm_path, size);
+ shm_path = shmfd->shm_path;
+ if (shm_path != NULL) {
+ pr_path = curthread->td_ucred->cr_prison->pr_path;
+ if (strcmp(pr_path, "/") != 0) {
+ /* Return the jail-rooted pathname. */
+ pr_pathlen = strlen(pr_path);
+ if (strncmp(shm_path, pr_path, pr_pathlen) == 0 &&
+ shm_path[pr_pathlen] == '/')
+ shm_path += pr_pathlen;
+ }
+ strlcpy(path, shm_path, size);
+ }
sx_sunlock(&shm_dict_lock);
}
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