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authorLinus Torvalds <torvalds@linux-foundation.org>2017-07-21 16:24:22 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-07-21 16:24:22 -0700
commit99313414dda451a8c00b139afc77a803e647f309 (patch)
tree8f23042ffbbd231154c6eceb469fcb9c941c4b7f /fs
parent0151ef0085f946eed75da851297577f88d74c50c (diff)
parent0e082555cec9510d276965fe391f709acb32c0f4 (diff)
downloadlinux-stericsson-99313414dda451a8c00b139afc77a803e647f309.tar.gz
Merge branch 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs
Pull overlayfs fixes from Miklos Szeredi: "This fixes a crash with SELinux and several other old and new bugs" * 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: ovl: check for bad and whiteout index on lookup ovl: do not cleanup directory and whiteout index entries ovl: fix xattr get and set with selinux ovl: remove unneeded check for IS_ERR() ovl: fix origin verification of index dir ovl: mark parent impure on ovl_link() ovl: fix random return value on mount
Diffstat (limited to 'fs')
-rw-r--r--fs/overlayfs/dir.c22
-rw-r--r--fs/overlayfs/inode.c32
-rw-r--r--fs/overlayfs/namei.c41
-rw-r--r--fs/overlayfs/overlayfs.h10
-rw-r--r--fs/overlayfs/readdir.c5
-rw-r--r--fs/overlayfs/super.c13
-rw-r--r--fs/overlayfs/util.c7
7 files changed, 88 insertions, 42 deletions
diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index 641d9ee97f91..48b70e6490f3 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -481,17 +481,30 @@ out_cleanup:
}
static int ovl_create_or_link(struct dentry *dentry, struct inode *inode,
- struct cattr *attr, struct dentry *hardlink)
+ struct cattr *attr, struct dentry *hardlink,
+ bool origin)
{
int err;
const struct cred *old_cred;
struct cred *override_cred;
+ struct dentry *parent = dentry->d_parent;
- err = ovl_copy_up(dentry->d_parent);
+ err = ovl_copy_up(parent);
if (err)
return err;
old_cred = ovl_override_creds(dentry->d_sb);
+
+ /*
+ * When linking a file with copy up origin into a new parent, mark the
+ * new parent dir "impure".
+ */
+ if (origin) {
+ err = ovl_set_impure(parent, ovl_dentry_upper(parent));
+ if (err)
+ goto out_revert_creds;
+ }
+
err = -ENOMEM;
override_cred = prepare_creds();
if (override_cred) {
@@ -550,7 +563,7 @@ static int ovl_create_object(struct dentry *dentry, int mode, dev_t rdev,
inode_init_owner(inode, dentry->d_parent->d_inode, mode);
attr.mode = inode->i_mode;
- err = ovl_create_or_link(dentry, inode, &attr, NULL);
+ err = ovl_create_or_link(dentry, inode, &attr, NULL, false);
if (err)
iput(inode);
@@ -609,7 +622,8 @@ static int ovl_link(struct dentry *old, struct inode *newdir,
inode = d_inode(old);
ihold(inode);
- err = ovl_create_or_link(new, inode, NULL, ovl_dentry_upper(old));
+ err = ovl_create_or_link(new, inode, NULL, ovl_dentry_upper(old),
+ ovl_type_origin(old));
if (err)
iput(inode);
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 69f4fc26ee39..5bc71642b226 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -202,37 +202,38 @@ bool ovl_is_private_xattr(const char *name)
sizeof(OVL_XATTR_PREFIX) - 1) == 0;
}
-int ovl_xattr_set(struct dentry *dentry, const char *name, const void *value,
- size_t size, int flags)
+int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name,
+ const void *value, size_t size, int flags)
{
int err;
- struct path realpath;
- enum ovl_path_type type = ovl_path_real(dentry, &realpath);
+ struct dentry *upperdentry = ovl_i_dentry_upper(inode);
+ struct dentry *realdentry = upperdentry ?: ovl_dentry_lower(dentry);
const struct cred *old_cred;
err = ovl_want_write(dentry);
if (err)
goto out;
- if (!value && !OVL_TYPE_UPPER(type)) {
- err = vfs_getxattr(realpath.dentry, name, NULL, 0);
+ if (!value && !upperdentry) {
+ err = vfs_getxattr(realdentry, name, NULL, 0);
if (err < 0)
goto out_drop_write;
}
- err = ovl_copy_up(dentry);
- if (err)
- goto out_drop_write;
+ if (!upperdentry) {
+ err = ovl_copy_up(dentry);
+ if (err)
+ goto out_drop_write;
- if (!OVL_TYPE_UPPER(type))
- ovl_path_upper(dentry, &realpath);
+ realdentry = ovl_dentry_upper(dentry);
+ }
old_cred = ovl_override_creds(dentry->d_sb);
if (value)
- err = vfs_setxattr(realpath.dentry, name, value, size, flags);
+ err = vfs_setxattr(realdentry, name, value, size, flags);
else {
WARN_ON(flags != XATTR_REPLACE);
- err = vfs_removexattr(realpath.dentry, name);
+ err = vfs_removexattr(realdentry, name);
}
revert_creds(old_cred);
@@ -242,12 +243,13 @@ out:
return err;
}
-int ovl_xattr_get(struct dentry *dentry, const char *name,
+int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name,
void *value, size_t size)
{
- struct dentry *realdentry = ovl_dentry_real(dentry);
ssize_t res;
const struct cred *old_cred;
+ struct dentry *realdentry =
+ ovl_i_dentry_upper(inode) ?: ovl_dentry_lower(dentry);
old_cred = ovl_override_creds(dentry->d_sb);
res = vfs_getxattr(realdentry, name, value, size);
diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c
index 9bc0e580a5b3..8aef2b304b2d 100644
--- a/fs/overlayfs/namei.c
+++ b/fs/overlayfs/namei.c
@@ -397,8 +397,19 @@ int ovl_verify_index(struct dentry *index, struct path *lowerstack,
if (!d_inode(index))
return 0;
- err = -EISDIR;
- if (d_is_dir(index))
+ /*
+ * Directory index entries are going to be used for looking up
+ * redirected upper dirs by lower dir fh when decoding an overlay
+ * file handle of a merge dir. Whiteout index entries are going to be
+ * used as an indication that an exported overlay file handle should
+ * be treated as stale (i.e. after unlink of the overlay inode).
+ * We don't know the verification rules for directory and whiteout
+ * index entries, because they have not been implemented yet, so return
+ * EROFS if those entries are found to avoid corrupting an index that
+ * was created by a newer kernel.
+ */
+ err = -EROFS;
+ if (d_is_dir(index) || ovl_is_whiteout(index))
goto fail;
err = -EINVAL;
@@ -436,8 +447,8 @@ out:
return err;
fail:
- pr_warn_ratelimited("overlayfs: failed to verify index (%pd2, err=%i)\n",
- index, err);
+ pr_warn_ratelimited("overlayfs: failed to verify index (%pd2, ftype=%x, err=%i)\n",
+ index, d_inode(index)->i_mode & S_IFMT, err);
goto out;
}
@@ -502,6 +513,7 @@ static struct dentry *ovl_lookup_index(struct dentry *dentry,
goto out;
}
+ inode = d_inode(index);
if (d_is_negative(index)) {
if (upper && d_inode(origin)->i_nlink > 1) {
pr_warn_ratelimited("overlayfs: hard link with origin but no index (ino=%lu).\n",
@@ -511,11 +523,22 @@ static struct dentry *ovl_lookup_index(struct dentry *dentry,
dput(index);
index = NULL;
- } else if (upper && d_inode(index) != d_inode(upper)) {
- inode = d_inode(index);
- pr_warn_ratelimited("overlayfs: wrong index found (index ino: %lu, upper ino: %lu).\n",
- d_inode(index)->i_ino,
- d_inode(upper)->i_ino);
+ } else if (upper && d_inode(upper) != inode) {
+ pr_warn_ratelimited("overlayfs: wrong index found (index=%pd2, ino=%lu, upper ino=%lu).\n",
+ index, inode->i_ino, d_inode(upper)->i_ino);
+ goto fail;
+ } else if (ovl_dentry_weird(index) || ovl_is_whiteout(index) ||
+ ((inode->i_mode ^ d_inode(origin)->i_mode) & S_IFMT)) {
+ /*
+ * Index should always be of the same file type as origin
+ * except for the case of a whiteout index. A whiteout
+ * index should only exist if all lower aliases have been
+ * unlinked, which means that finding a lower origin on lookup
+ * whose index is a whiteout should be treated as an error.
+ */
+ pr_warn_ratelimited("overlayfs: bad index found (index=%pd2, ftype=%x, origin ftype=%x).\n",
+ index, d_inode(index)->i_mode & S_IFMT,
+ d_inode(origin)->i_mode & S_IFMT);
goto fail;
}
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 60d26605e039..e927a62c97ae 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -47,7 +47,8 @@ enum ovl_flag {
/* Is the real inode encoded in fid an upper inode? */
#define OVL_FH_FLAG_PATH_UPPER (1 << 2)
-#define OVL_FH_FLAG_ALL (OVL_FH_FLAG_BIG_ENDIAN | OVL_FH_FLAG_ANY_ENDIAN)
+#define OVL_FH_FLAG_ALL (OVL_FH_FLAG_BIG_ENDIAN | OVL_FH_FLAG_ANY_ENDIAN | \
+ OVL_FH_FLAG_PATH_UPPER)
#if defined(__LITTLE_ENDIAN)
#define OVL_FH_FLAG_CPU_ENDIAN 0
@@ -199,6 +200,7 @@ enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path);
struct dentry *ovl_dentry_upper(struct dentry *dentry);
struct dentry *ovl_dentry_lower(struct dentry *dentry);
struct dentry *ovl_dentry_real(struct dentry *dentry);
+struct dentry *ovl_i_dentry_upper(struct inode *inode);
struct inode *ovl_inode_upper(struct inode *inode);
struct inode *ovl_inode_lower(struct inode *inode);
struct inode *ovl_inode_real(struct inode *inode);
@@ -270,9 +272,9 @@ int ovl_setattr(struct dentry *dentry, struct iattr *attr);
int ovl_getattr(const struct path *path, struct kstat *stat,
u32 request_mask, unsigned int flags);
int ovl_permission(struct inode *inode, int mask);
-int ovl_xattr_set(struct dentry *dentry, const char *name, const void *value,
- size_t size, int flags);
-int ovl_xattr_get(struct dentry *dentry, const char *name,
+int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name,
+ const void *value, size_t size, int flags);
+int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name,
void *value, size_t size);
ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size);
struct posix_acl *ovl_get_acl(struct inode *inode, int type);
diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c
index 0298463cf9c3..3d424a51cabb 100644
--- a/fs/overlayfs/readdir.c
+++ b/fs/overlayfs/readdir.c
@@ -703,7 +703,10 @@ int ovl_indexdir_cleanup(struct dentry *dentry, struct vfsmount *mnt,
err = PTR_ERR(index);
break;
}
- if (ovl_verify_index(index, lowerstack, numlower)) {
+ err = ovl_verify_index(index, lowerstack, numlower);
+ if (err) {
+ if (err == -EROFS)
+ break;
err = ovl_cleanup(dir, index);
if (err)
break;
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 44dc2d6ffe0f..d86e89f97201 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -692,7 +692,7 @@ ovl_posix_acl_xattr_get(const struct xattr_handler *handler,
struct dentry *dentry, struct inode *inode,
const char *name, void *buffer, size_t size)
{
- return ovl_xattr_get(dentry, handler->name, buffer, size);
+ return ovl_xattr_get(dentry, inode, handler->name, buffer, size);
}
static int __maybe_unused
@@ -742,7 +742,7 @@ ovl_posix_acl_xattr_set(const struct xattr_handler *handler,
return err;
}
- err = ovl_xattr_set(dentry, handler->name, value, size, flags);
+ err = ovl_xattr_set(dentry, inode, handler->name, value, size, flags);
if (!err)
ovl_copyattr(ovl_inode_real(inode), inode);
@@ -772,7 +772,7 @@ static int ovl_other_xattr_get(const struct xattr_handler *handler,
struct dentry *dentry, struct inode *inode,
const char *name, void *buffer, size_t size)
{
- return ovl_xattr_get(dentry, name, buffer, size);
+ return ovl_xattr_get(dentry, inode, name, buffer, size);
}
static int ovl_other_xattr_set(const struct xattr_handler *handler,
@@ -780,7 +780,7 @@ static int ovl_other_xattr_set(const struct xattr_handler *handler,
const char *name, const void *value,
size_t size, int flags)
{
- return ovl_xattr_set(dentry, name, value, size, flags);
+ return ovl_xattr_set(dentry, inode, name, value, size, flags);
}
static const struct xattr_handler __maybe_unused
@@ -1058,10 +1058,6 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
ufs->indexdir = ovl_workdir_create(sb, ufs, workpath.dentry,
OVL_INDEXDIR_NAME, true);
- err = PTR_ERR(ufs->indexdir);
- if (IS_ERR(ufs->indexdir))
- goto out_put_lower_mnt;
-
if (ufs->indexdir) {
/* Verify upper root is index dir origin */
err = ovl_verify_origin(ufs->indexdir, ufs->upper_mnt,
@@ -1090,6 +1086,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
else
sb->s_d_op = &ovl_dentry_operations;
+ err = -ENOMEM;
ufs->creator_cred = cred = prepare_creds();
if (!cred)
goto out_put_indexdir;
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index c492ba75c659..f46ad75dc96a 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -157,9 +157,14 @@ struct dentry *ovl_dentry_real(struct dentry *dentry)
return ovl_dentry_upper(dentry) ?: ovl_dentry_lower(dentry);
}
+struct dentry *ovl_i_dentry_upper(struct inode *inode)
+{
+ return ovl_upperdentry_dereference(OVL_I(inode));
+}
+
struct inode *ovl_inode_upper(struct inode *inode)
{
- struct dentry *upperdentry = ovl_upperdentry_dereference(OVL_I(inode));
+ struct dentry *upperdentry = ovl_i_dentry_upper(inode);
return upperdentry ? d_inode(upperdentry) : NULL;
}