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author | Miklos Szeredi <mszeredi@redhat.com> | 2016-09-16 14:12:11 +0200 |
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committer | Miklos Szeredi <mszeredi@redhat.com> | 2016-09-16 14:12:11 +0200 |
commit | 2b6bc7f48d34a6043915beddbf53b981603737c8 (patch) | |
tree | ab544e0b8c1c33dba94d79edeb0be310a51499ca /fs/overlayfs/super.c | |
parent | 8b326c61de08f5ca4bc454a168f19e7e43c4cc2a (diff) | |
download | linux-stable-2b6bc7f48d34a6043915beddbf53b981603737c8.tar.gz linux-stable-2b6bc7f48d34a6043915beddbf53b981603737c8.tar.bz2 linux-stable-2b6bc7f48d34a6043915beddbf53b981603737c8.zip |
ovl: lookup: do getxattr with mounter's permission
The getxattr() in ovl_is_opaquedir() was missed when converting all
operations on underlying fs to be done under mounter's permission.
This patch fixes this by moving the ovl_override_creds()/revert_creds() out
from ovl_lookup_real() to ovl_lookup().
Also convert to using vfs_getxattr() instead of directly calling
i_op->getxattr().
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'fs/overlayfs/super.c')
-rw-r--r-- | fs/overlayfs/super.c | 20 |
1 files changed, 9 insertions, 11 deletions
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index e2a94a26767b..8ccebaf64c5b 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -273,12 +273,11 @@ static bool ovl_is_opaquedir(struct dentry *dentry) { int res; char val; - struct inode *inode = dentry->d_inode; - if (!S_ISDIR(inode->i_mode) || !inode->i_op->getxattr) + if (!d_is_dir(dentry)) return false; - res = inode->i_op->getxattr(dentry, inode, OVL_XATTR_OPAQUE, &val, 1); + res = vfs_getxattr(dentry, OVL_XATTR_OPAQUE, &val, 1); if (res == 1 && val == 'y') return true; @@ -419,16 +418,12 @@ static bool ovl_dentry_weird(struct dentry *dentry) DCACHE_OP_COMPARE); } -static inline struct dentry *ovl_lookup_real(struct super_block *ovl_sb, - struct dentry *dir, +static inline struct dentry *ovl_lookup_real(struct dentry *dir, const struct qstr *name) { - const struct cred *old_cred; struct dentry *dentry; - old_cred = ovl_override_creds(ovl_sb); dentry = lookup_one_len_unlocked(name->name, dir, name->len); - revert_creds(old_cred); if (IS_ERR(dentry)) { if (PTR_ERR(dentry) == -ENOENT) @@ -469,6 +464,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) { struct ovl_entry *oe; + const struct cred *old_cred; struct ovl_entry *poe = dentry->d_parent->d_fsdata; struct path *stack = NULL; struct dentry *upperdir, *upperdentry = NULL; @@ -479,9 +475,10 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, unsigned int i; int err; + old_cred = ovl_override_creds(dentry->d_sb); upperdir = ovl_upperdentry_dereference(poe); if (upperdir) { - this = ovl_lookup_real(dentry->d_sb, upperdir, &dentry->d_name); + this = ovl_lookup_real(upperdir, &dentry->d_name); err = PTR_ERR(this); if (IS_ERR(this)) goto out; @@ -514,8 +511,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, bool opaque = false; struct path lowerpath = poe->lowerstack[i]; - this = ovl_lookup_real(dentry->d_sb, - lowerpath.dentry, &dentry->d_name); + this = ovl_lookup_real(lowerpath.dentry, &dentry->d_name); err = PTR_ERR(this); if (IS_ERR(this)) { /* @@ -588,6 +584,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, ovl_copyattr(realdentry->d_inode, inode); } + revert_creds(old_cred); oe->opaque = upperopaque; oe->__upperdentry = upperdentry; memcpy(oe->lowerstack, stack, sizeof(struct path) * ctr); @@ -606,6 +603,7 @@ out_put: out_put_upper: dput(upperdentry); out: + revert_creds(old_cred); return ERR_PTR(err); } |