Merge tag 'ovl-fixes-5.5-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/mszere...

[platform/kernel/linux-starfive.git] / fs / overlayfs / namei.c

diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c
index c269d60..76ff663 100644 (file)
--- a/fs/overlayfs/namei.c
+++ b/fs/overlayfs/namei.c
@@ -84,21 +84,21 @@ static int ovl_acceptable(void *ctx, struct dentry *dentry)
  * Return -ENODATA for "origin unknown".
  * Return <0 for an invalid file handle.
  */
-int ovl_check_fh_len(struct ovl_fh *fh, int fh_len)
+int ovl_check_fb_len(struct ovl_fb *fb, int fb_len)
 {
-       if (fh_len < sizeof(struct ovl_fh) || fh_len < fh->len)
+       if (fb_len < sizeof(struct ovl_fb) || fb_len < fb->len)
                return -EINVAL;
 
-       if (fh->magic != OVL_FH_MAGIC)
+       if (fb->magic != OVL_FH_MAGIC)
                return -EINVAL;
 
        /* Treat larger version and unknown flags as "origin unknown" */
-       if (fh->version > OVL_FH_VERSION || fh->flags & ~OVL_FH_FLAG_ALL)
+       if (fb->version > OVL_FH_VERSION || fb->flags & ~OVL_FH_FLAG_ALL)
                return -ENODATA;
 
        /* Treat endianness mismatch as "origin unknown" */
-       if (!(fh->flags & OVL_FH_FLAG_ANY_ENDIAN) &&
-           (fh->flags & OVL_FH_FLAG_BIG_ENDIAN) != OVL_FH_FLAG_CPU_ENDIAN)
+       if (!(fb->flags & OVL_FH_FLAG_ANY_ENDIAN) &&
+           (fb->flags & OVL_FH_FLAG_BIG_ENDIAN) != OVL_FH_FLAG_CPU_ENDIAN)
                return -ENODATA;
 
        return 0;
@@ -119,15 +119,15 @@ static struct ovl_fh *ovl_get_fh(struct dentry *dentry, const char *name)
        if (res == 0)
                return NULL;
 
-       fh = kzalloc(res, GFP_KERNEL);
+       fh = kzalloc(res + OVL_FH_WIRE_OFFSET, GFP_KERNEL);
        if (!fh)
                return ERR_PTR(-ENOMEM);
 
-       res = vfs_getxattr(dentry, name, fh, res);
+       res = vfs_getxattr(dentry, name, fh->buf, res);
        if (res < 0)
                goto fail;
 
-       err = ovl_check_fh_len(fh, res);
+       err = ovl_check_fb_len(&fh->fb, res);
        if (err < 0) {
                if (err == -ENODATA)
                        goto out;
@@ -158,12 +158,12 @@ struct dentry *ovl_decode_real_fh(struct ovl_fh *fh, struct vfsmount *mnt,
         * Make sure that the stored uuid matches the uuid of the lower
         * layer where file handle will be decoded.
         */
-       if (!uuid_equal(&fh->uuid, &mnt->mnt_sb->s_uuid))
+       if (!uuid_equal(&fh->fb.uuid, &mnt->mnt_sb->s_uuid))
                return NULL;
 
-       bytes = (fh->len - offsetof(struct ovl_fh, fid));
-       real = exportfs_decode_fh(mnt, (struct fid *)fh->fid,
-                                 bytes >> 2, (int)fh->type,
+       bytes = (fh->fb.len - offsetof(struct ovl_fb, fid));
+       real = exportfs_decode_fh(mnt, (struct fid *)fh->fb.fid,
+                                 bytes >> 2, (int)fh->fb.type,
                                  connected ? ovl_acceptable : NULL, mnt);
        if (IS_ERR(real)) {
                /*
@@ -173,7 +173,7 @@ struct dentry *ovl_decode_real_fh(struct ovl_fh *fh, struct vfsmount *mnt,
                 * index entries correctly.
                 */
                if (real == ERR_PTR(-ESTALE) &&
-                   !(fh->flags & OVL_FH_FLAG_PATH_UPPER))
+                   !(fh->fb.flags & OVL_FH_FLAG_PATH_UPPER))
                        real = NULL;
                return real;
        }
@@ -323,6 +323,14 @@ int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected,
        int i;
 
        for (i = 0; i < ofs->numlower; i++) {
+               /*
+                * If lower fs uuid is not unique among lower fs we cannot match
+                * fh->uuid to layer.
+                */
+               if (ofs->lower_layers[i].fsid &&
+                   ofs->lower_layers[i].fs->bad_uuid)
+                       continue;
+
                origin = ovl_decode_real_fh(fh, ofs->lower_layers[i].mnt,
                                            connected);
                if (origin)
@@ -400,7 +408,7 @@ static int ovl_verify_fh(struct dentry *dentry, const char *name,
        if (IS_ERR(ofh))
                return PTR_ERR(ofh);
 
-       if (fh->len != ofh->len || memcmp(fh, ofh, fh->len))
+       if (fh->fb.len != ofh->fb.len || memcmp(&fh->fb, &ofh->fb, fh->fb.len))
                err = -ESTALE;
 
        kfree(ofh);
@@ -431,7 +439,7 @@ int ovl_verify_set_fh(struct dentry *dentry, const char *name,
 
        err = ovl_verify_fh(dentry, name, fh);
        if (set && err == -ENODATA)
-               err = ovl_do_setxattr(dentry, name, fh, fh->len, 0);
+               err = ovl_do_setxattr(dentry, name, fh->buf, fh->fb.len, 0);
        if (err)
                goto fail;
 
@@ -505,20 +513,20 @@ int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index)
                goto fail;
 
        err = -EINVAL;
-       if (index->d_name.len < sizeof(struct ovl_fh)*2)
+       if (index->d_name.len < sizeof(struct ovl_fb)*2)
                goto fail;
 
        err = -ENOMEM;
        len = index->d_name.len / 2;
-       fh = kzalloc(len, GFP_KERNEL);
+       fh = kzalloc(len + OVL_FH_WIRE_OFFSET, GFP_KERNEL);
        if (!fh)
                goto fail;
 
        err = -EINVAL;
-       if (hex2bin((u8 *)fh, index->d_name.name, len))
+       if (hex2bin(fh->buf, index->d_name.name, len))
                goto fail;
 
-       err = ovl_check_fh_len(fh, len);
+       err = ovl_check_fb_len(&fh->fb, len);
        if (err)
                goto fail;
 
@@ -597,11 +605,11 @@ static int ovl_get_index_name_fh(struct ovl_fh *fh, struct qstr *name)
 {
        char *n, *s;
 
-       n = kcalloc(fh->len, 2, GFP_KERNEL);
+       n = kcalloc(fh->fb.len, 2, GFP_KERNEL);
        if (!n)
                return -ENOMEM;
 
-       s  = bin2hex(n, fh, fh->len);
+       s  = bin2hex(n, fh->buf, fh->fb.len);
        *name = (struct qstr) QSTR_INIT(n, s - n);
 
        return 0;