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authorLinus Torvalds <torvalds@linux-foundation.org>2019-12-14 22:13:54 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2019-12-14 22:13:54 +0300
commit81c64b0bd0900405b4e55f3d48a2fc7dd5e1676c (patch)
treea4cdfebf4e3e39bd80b1685c389ffea04baaf8dd /fs/overlayfs/namei.c
parente31736d9fae841e8a1612f263136454af10f476a (diff)
parent35c6cb41686c4de03d738fd95617a0cf7441bbe1 (diff)
downloadlinux-81c64b0bd0900405b4e55f3d48a2fc7dd5e1676c.tar.xz
Merge tag 'ovl-fixes-5.5-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs
Pull overlayfs fixes from Miklos Szeredi: "Fix some bugs and documentation" * tag 'ovl-fixes-5.5-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: docs: filesystems: overlayfs: Fix restview warnings docs: filesystems: overlayfs: Rename overlayfs.txt to .rst ovl: relax WARN_ON() on rename to self ovl: fix corner case of non-unique st_dev;st_ino ovl: don't use a temp buf for encoding real fh ovl: make sure that real fid is 32bit aligned in memory ovl: fix lookup failure on multi lower squashfs
Diffstat (limited to 'fs/overlayfs/namei.c')
-rw-r--r--fs/overlayfs/namei.c52
1 files changed, 30 insertions, 22 deletions
diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c
index c269d6033525..76ff66339173 100644
--- 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;