Home Home > GIT Browse
summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorJan Kara <jack@suse.cz>2016-09-19 17:39:09 +0200
committerJan Kara <jack@suse.cz>2016-09-22 10:55:32 +0200
commit073931017b49d9458aa351605b43a7e34598caef (patch)
tree8c4374e82e5cad92bdb589e5be417f1a94870399
parent5d3ddd84eaefffd23c028bce5610dac8726f71c1 (diff)
posix_acl: Clear SGID bit when setting file permissions
When file permissions are modified via chmod(2) and the user is not in the owning group or capable of CAP_FSETID, the setgid bit is cleared in inode_change_ok(). Setting a POSIX ACL via setxattr(2) sets the file permissions as well as the new ACL, but doesn't clear the setgid bit in a similar way; this allows to bypass the check in chmod(2). Fix that. References: CVE-2016-7097 Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
-rw-r--r--fs/9p/acl.c40
-rw-r--r--fs/btrfs/acl.c6
-rw-r--r--fs/ceph/acl.c6
-rw-r--r--fs/ext2/acl.c12
-rw-r--r--fs/ext4/acl.c12
-rw-r--r--fs/f2fs/acl.c6
-rw-r--r--fs/gfs2/acl.c12
-rw-r--r--fs/hfsplus/posix_acl.c4
-rw-r--r--fs/jffs2/acl.c9
-rw-r--r--fs/jfs/acl.c6
-rw-r--r--fs/ocfs2/acl.c10
-rw-r--r--fs/orangefs/acl.c15
-rw-r--r--fs/posix_acl.c31
-rw-r--r--fs/reiserfs/xattr_acl.c8
-rw-r--r--fs/xfs/xfs_acl.c13
-rw-r--r--include/linux/posix_acl.h1
16 files changed, 89 insertions, 102 deletions
diff --git a/fs/9p/acl.c b/fs/9p/acl.c
index 5b6a1743ea17..b3c2cc79c20d 100644
--- a/fs/9p/acl.c
+++ b/fs/9p/acl.c
@@ -276,32 +276,26 @@ static int v9fs_xattr_set_acl(const struct xattr_handler *handler,
switch (handler->flags) {
case ACL_TYPE_ACCESS:
if (acl) {
- umode_t mode = inode->i_mode;
- retval = posix_acl_equiv_mode(acl, &mode);
- if (retval < 0)
+ struct iattr iattr;
+
+ retval = posix_acl_update_mode(inode, &iattr.ia_mode, &acl);
+ if (retval)
goto err_out;
- else {
- struct iattr iattr;
- if (retval == 0) {
- /*
- * ACL can be represented
- * by the mode bits. So don't
- * update ACL.
- */
- acl = NULL;
- value = NULL;
- size = 0;
- }
- /* Updte the mode bits */
- iattr.ia_mode = ((mode & S_IALLUGO) |
- (inode->i_mode & ~S_IALLUGO));
- iattr.ia_valid = ATTR_MODE;
- /* FIXME should we update ctime ?
- * What is the following setxattr update the
- * mode ?
+ if (!acl) {
+ /*
+ * ACL can be represented
+ * by the mode bits. So don't
+ * update ACL.
*/
- v9fs_vfs_setattr_dotl(dentry, &iattr);
+ value = NULL;
+ size = 0;
}
+ iattr.ia_valid = ATTR_MODE;
+ /* FIXME should we update ctime ?
+ * What is the following setxattr update the
+ * mode ?
+ */
+ v9fs_vfs_setattr_dotl(dentry, &iattr);
}
break;
case ACL_TYPE_DEFAULT:
diff --git a/fs/btrfs/acl.c b/fs/btrfs/acl.c
index 53bb7af4e5f0..247b8dfaf6e5 100644
--- a/fs/btrfs/acl.c
+++ b/fs/btrfs/acl.c
@@ -79,11 +79,9 @@ static int __btrfs_set_acl(struct btrfs_trans_handle *trans,
case ACL_TYPE_ACCESS:
name = XATTR_NAME_POSIX_ACL_ACCESS;
if (acl) {
- ret = posix_acl_equiv_mode(acl, &inode->i_mode);
- if (ret < 0)
+ ret = posix_acl_update_mode(inode, &inode->i_mode, &acl);
+ if (ret)
return ret;
- if (ret == 0)
- acl = NULL;
}
ret = 0;
break;
diff --git a/fs/ceph/acl.c b/fs/ceph/acl.c
index 4f67227f69a5..d0b6b342dff9 100644
--- a/fs/ceph/acl.c
+++ b/fs/ceph/acl.c
@@ -95,11 +95,9 @@ int ceph_set_acl(struct inode *inode, struct posix_acl *acl, int type)
case ACL_TYPE_ACCESS:
name = XATTR_NAME_POSIX_ACL_ACCESS;
if (acl) {
- ret = posix_acl_equiv_mode(acl, &new_mode);
- if (ret < 0)
+ ret = posix_acl_update_mode(inode, &new_mode, &acl);
+ if (ret)
goto out;
- if (ret == 0)
- acl = NULL;
}
break;
case ACL_TYPE_DEFAULT:
diff --git a/fs/ext2/acl.c b/fs/ext2/acl.c
index 42f1d1814083..e725aa0890e0 100644
--- a/fs/ext2/acl.c
+++ b/fs/ext2/acl.c
@@ -190,15 +190,11 @@ ext2_set_acl(struct inode *inode, struct posix_acl *acl, int type)
case ACL_TYPE_ACCESS:
name_index = EXT2_XATTR_INDEX_POSIX_ACL_ACCESS;
if (acl) {
- error = posix_acl_equiv_mode(acl, &inode->i_mode);
- if (error < 0)
+ error = posix_acl_update_mode(inode, &inode->i_mode, &acl);
+ if (error)
return error;
- else {
- inode->i_ctime = CURRENT_TIME_SEC;
- mark_inode_dirty(inode);
- if (error == 0)
- acl = NULL;
- }
+ inode->i_ctime = CURRENT_TIME_SEC;
+ mark_inode_dirty(inode);
}
break;
diff --git a/fs/ext4/acl.c b/fs/ext4/acl.c
index c6601a476c02..dfa519979038 100644
--- a/fs/ext4/acl.c
+++ b/fs/ext4/acl.c
@@ -193,15 +193,11 @@ __ext4_set_acl(handle_t *handle, struct inode *inode, int type,
case ACL_TYPE_ACCESS:
name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS;
if (acl) {
- error = posix_acl_equiv_mode(acl, &inode->i_mode);
- if (error < 0)
+ error = posix_acl_update_mode(inode, &inode->i_mode, &acl);
+ if (error)
return error;
- else {
- inode->i_ctime = ext4_current_time(inode);
- ext4_mark_inode_dirty(handle, inode);
- if (error == 0)
- acl = NULL;
- }
+ inode->i_ctime = ext4_current_time(inode);
+ ext4_mark_inode_dirty(handle, inode);
}
break;
diff --git a/fs/f2fs/acl.c b/fs/f2fs/acl.c
index 4dcc9e28dc5c..31344247ce89 100644
--- a/fs/f2fs/acl.c
+++ b/fs/f2fs/acl.c
@@ -210,12 +210,10 @@ static int __f2fs_set_acl(struct inode *inode, int type,
case ACL_TYPE_ACCESS:
name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;
if (acl) {
- error = posix_acl_equiv_mode(acl, &inode->i_mode);
- if (error < 0)
+ error = posix_acl_update_mode(inode, &inode->i_mode, &acl);
+ if (error)
return error;
set_acl_inode(inode, inode->i_mode);
- if (error == 0)
- acl = NULL;
}
break;
diff --git a/fs/gfs2/acl.c b/fs/gfs2/acl.c
index 363ba9e9d8d0..2524807ee070 100644
--- a/fs/gfs2/acl.c
+++ b/fs/gfs2/acl.c
@@ -92,17 +92,11 @@ int __gfs2_set_acl(struct inode *inode, struct posix_acl *acl, int type)
if (type == ACL_TYPE_ACCESS) {
umode_t mode = inode->i_mode;
- error = posix_acl_equiv_mode(acl, &mode);
- if (error < 0)
+ error = posix_acl_update_mode(inode, &inode->i_mode, &acl);
+ if (error)
return error;
-
- if (error == 0)
- acl = NULL;
-
- if (mode != inode->i_mode) {
- inode->i_mode = mode;
+ if (mode != inode->i_mode)
mark_inode_dirty(inode);
- }
}
if (acl) {
diff --git a/fs/hfsplus/posix_acl.c b/fs/hfsplus/posix_acl.c
index ab7ea2506b4d..9b92058a1240 100644
--- a/fs/hfsplus/posix_acl.c
+++ b/fs/hfsplus/posix_acl.c
@@ -65,8 +65,8 @@ int hfsplus_set_posix_acl(struct inode *inode, struct posix_acl *acl,
case ACL_TYPE_ACCESS:
xattr_name = XATTR_NAME_POSIX_ACL_ACCESS;
if (acl) {
- err = posix_acl_equiv_mode(acl, &inode->i_mode);
- if (err < 0)
+ err = posix_acl_update_mode(inode, &inode->i_mode, &acl);
+ if (err)
return err;
}
err = 0;
diff --git a/fs/jffs2/acl.c b/fs/jffs2/acl.c
index bc2693d56298..2a0f2a1044c1 100644
--- a/fs/jffs2/acl.c
+++ b/fs/jffs2/acl.c
@@ -233,9 +233,10 @@ int jffs2_set_acl(struct inode *inode, struct posix_acl *acl, int type)
case ACL_TYPE_ACCESS:
xprefix = JFFS2_XPREFIX_ACL_ACCESS;
if (acl) {
- umode_t mode = inode->i_mode;
- rc = posix_acl_equiv_mode(acl, &mode);
- if (rc < 0)
+ umode_t mode;
+
+ rc = posix_acl_update_mode(inode, &mode, &acl);
+ if (rc)
return rc;
if (inode->i_mode != mode) {
struct iattr attr;
@@ -247,8 +248,6 @@ int jffs2_set_acl(struct inode *inode, struct posix_acl *acl, int type)
if (rc < 0)
return rc;
}
- if (rc == 0)
- acl = NULL;
}
break;
case ACL_TYPE_DEFAULT:
diff --git a/fs/jfs/acl.c b/fs/jfs/acl.c
index 21fa92ba2c19..3a1e1554a4e3 100644
--- a/fs/jfs/acl.c
+++ b/fs/jfs/acl.c
@@ -78,13 +78,11 @@ static int __jfs_set_acl(tid_t tid, struct inode *inode, int type,
case ACL_TYPE_ACCESS:
ea_name = XATTR_NAME_POSIX_ACL_ACCESS;
if (acl) {
- rc = posix_acl_equiv_mode(acl, &inode->i_mode);
- if (rc < 0)
+ rc = posix_acl_update_mode(inode, &inode->i_mode, &acl);
+ if (rc)
return rc;
inode->i_ctime = CURRENT_TIME;
mark_inode_dirty(inode);
- if (rc == 0)
- acl = NULL;
}
break;
case ACL_TYPE_DEFAULT:
diff --git a/fs/ocfs2/acl.c b/fs/ocfs2/acl.c
index 2162434728c0..164307b99405 100644
--- a/fs/ocfs2/acl.c
+++ b/fs/ocfs2/acl.c
@@ -241,13 +241,11 @@ int ocfs2_set_acl(handle_t *handle,
case ACL_TYPE_ACCESS:
name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
if (acl) {
- umode_t mode = inode->i_mode;
- ret = posix_acl_equiv_mode(acl, &mode);
- if (ret < 0)
- return ret;
+ umode_t mode;
- if (ret == 0)
- acl = NULL;
+ ret = posix_acl_update_mode(inode, &mode, &acl);
+ if (ret)
+ return ret;
ret = ocfs2_acl_set_mode(inode, di_bh,
handle, mode);
diff --git a/fs/orangefs/acl.c b/fs/orangefs/acl.c
index 28f2195cd798..7a3754488312 100644
--- a/fs/orangefs/acl.c
+++ b/fs/orangefs/acl.c
@@ -73,14 +73,11 @@ int orangefs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
case ACL_TYPE_ACCESS:
name = XATTR_NAME_POSIX_ACL_ACCESS;
if (acl) {
- umode_t mode = inode->i_mode;
- /*
- * can we represent this with the traditional file
- * mode permission bits?
- */
- error = posix_acl_equiv_mode(acl, &mode);
- if (error < 0) {
- gossip_err("%s: posix_acl_equiv_mode err: %d\n",
+ umode_t mode;
+
+ error = posix_acl_update_mode(inode, &mode, &acl);
+ if (error) {
+ gossip_err("%s: posix_acl_update_mode err: %d\n",
__func__,
error);
return error;
@@ -90,8 +87,6 @@ int orangefs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
SetModeFlag(orangefs_inode);
inode->i_mode = mode;
mark_inode_dirty_sync(inode);
- if (error == 0)
- acl = NULL;
}
break;
case ACL_TYPE_DEFAULT:
diff --git a/fs/posix_acl.c b/fs/posix_acl.c
index 59d47ab0791a..bfc3ec388322 100644
--- a/fs/posix_acl.c
+++ b/fs/posix_acl.c
@@ -626,6 +626,37 @@ no_mem:
}
EXPORT_SYMBOL_GPL(posix_acl_create);
+/**
+ * posix_acl_update_mode - update mode in set_acl
+ *
+ * Update the file mode when setting an ACL: compute the new file permission
+ * bits based on the ACL. In addition, if the ACL is equivalent to the new
+ * file mode, set *acl to NULL to indicate that no ACL should be set.
+ *
+ * As with chmod, clear the setgit bit if the caller is not in the owning group
+ * or capable of CAP_FSETID (see inode_change_ok).
+ *
+ * Called from set_acl inode operations.
+ */
+int posix_acl_update_mode(struct inode *inode, umode_t *mode_p,
+ struct posix_acl **acl)
+{
+ umode_t mode = inode->i_mode;
+ int error;
+
+ error = posix_acl_equiv_mode(*acl, &mode);
+ if (error < 0)
+ return error;
+ if (error == 0)
+ *acl = NULL;
+ if (!in_group_p(inode->i_gid) &&
+ !capable_wrt_inode_uidgid(inode, CAP_FSETID))
+ mode &= ~S_ISGID;
+ *mode_p = mode;
+ return 0;
+}
+EXPORT_SYMBOL(posix_acl_update_mode);
+
/*
* Fix up the uids and gids in posix acl extended attributes in place.
*/
diff --git a/fs/reiserfs/xattr_acl.c b/fs/reiserfs/xattr_acl.c
index dbed42f755e0..27376681c640 100644
--- a/fs/reiserfs/xattr_acl.c
+++ b/fs/reiserfs/xattr_acl.c
@@ -242,13 +242,9 @@ __reiserfs_set_acl(struct reiserfs_transaction_handle *th, struct inode *inode,
case ACL_TYPE_ACCESS:
name = XATTR_NAME_POSIX_ACL_ACCESS;
if (acl) {
- error = posix_acl_equiv_mode(acl, &inode->i_mode);
- if (error < 0)
+ error = posix_acl_update_mode(inode, &inode->i_mode, &acl);
+ if (error)
return error;
- else {
- if (error == 0)
- acl = NULL;
- }
}
break;
case ACL_TYPE_DEFAULT:
diff --git a/fs/xfs/xfs_acl.c b/fs/xfs/xfs_acl.c
index b6e527b8eccb..8a0dec89ca56 100644
--- a/fs/xfs/xfs_acl.c
+++ b/fs/xfs/xfs_acl.c
@@ -257,16 +257,11 @@ xfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
return error;
if (type == ACL_TYPE_ACCESS) {
- umode_t mode = inode->i_mode;
- error = posix_acl_equiv_mode(acl, &mode);
-
- if (error <= 0) {
- acl = NULL;
-
- if (error < 0)
- return error;
- }
+ umode_t mode;
+ error = posix_acl_update_mode(inode, &mode, &acl);
+ if (error)
+ return error;
error = xfs_set_mode(inode, mode);
if (error)
return error;
diff --git a/include/linux/posix_acl.h b/include/linux/posix_acl.h
index d5d3d741f028..bf1046d0397b 100644
--- a/include/linux/posix_acl.h
+++ b/include/linux/posix_acl.h
@@ -93,6 +93,7 @@ extern int set_posix_acl(struct inode *, int, struct posix_acl *);
extern int posix_acl_chmod(struct inode *, umode_t);
extern int posix_acl_create(struct inode *, umode_t *, struct posix_acl **,
struct posix_acl **);
+extern int posix_acl_update_mode(struct inode *, umode_t *, struct posix_acl **);
extern int simple_set_acl(struct inode *, struct posix_acl *, int);
extern int simple_acl_create(struct inode *, struct inode *);