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[PATCH] r/o bind mounts: prepare for write access checks: collapse if()
We're shortly going to be adding a bunch more permission checks in these functions. That requires adding either a bunch of new if() conditions, or some gotos. This patch collapses existing if()s and uses gotos instead to prepare for the upcoming changes. Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Acked-by: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Dave Hansen
Linus Torvalds
parent
db5fed26b2
commit
6902d925d5
93
fs/namei.c
93
fs/namei.c
@ -1934,30 +1934,32 @@ asmlinkage long sys_mkdirat(int dfd, const char __user *pathname, int mode)
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{
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int error = 0;
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char * tmp;
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struct dentry *dentry;
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struct nameidata nd;
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tmp = getname(pathname);
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error = PTR_ERR(tmp);
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if (!IS_ERR(tmp)) {
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struct dentry *dentry;
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struct nameidata nd;
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if (IS_ERR(tmp))
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goto out_err;
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error = do_path_lookup(dfd, tmp, LOOKUP_PARENT, &nd);
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if (error)
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goto out;
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dentry = lookup_create(&nd, 1);
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error = PTR_ERR(dentry);
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if (!IS_ERR(dentry)) {
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if (!IS_POSIXACL(nd.dentry->d_inode))
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mode &= ~current->fs->umask;
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error = vfs_mkdir(nd.dentry->d_inode, dentry, mode);
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dput(dentry);
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}
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mutex_unlock(&nd.dentry->d_inode->i_mutex);
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path_release(&nd);
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error = do_path_lookup(dfd, tmp, LOOKUP_PARENT, &nd);
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if (error)
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goto out;
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dentry = lookup_create(&nd, 1);
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error = PTR_ERR(dentry);
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if (IS_ERR(dentry))
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goto out_unlock;
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if (!IS_POSIXACL(nd.dentry->d_inode))
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mode &= ~current->fs->umask;
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error = vfs_mkdir(nd.dentry->d_inode, dentry, mode);
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dput(dentry);
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out_unlock:
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mutex_unlock(&nd.dentry->d_inode->i_mutex);
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path_release(&nd);
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out:
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putname(tmp);
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}
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putname(tmp);
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out_err:
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return error;
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}
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@ -2056,10 +2058,11 @@ static long do_rmdir(int dfd, const char __user *pathname)
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mutex_lock_nested(&nd.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
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dentry = lookup_hash(&nd);
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error = PTR_ERR(dentry);
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if (!IS_ERR(dentry)) {
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error = vfs_rmdir(nd.dentry->d_inode, dentry);
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dput(dentry);
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}
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if (IS_ERR(dentry))
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goto exit2;
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error = vfs_rmdir(nd.dentry->d_inode, dentry);
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dput(dentry);
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exit2:
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mutex_unlock(&nd.dentry->d_inode->i_mutex);
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exit1:
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path_release(&nd);
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@ -2199,30 +2202,33 @@ asmlinkage long sys_symlinkat(const char __user *oldname,
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int error = 0;
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char * from;
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char * to;
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struct dentry *dentry;
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struct nameidata nd;
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from = getname(oldname);
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if(IS_ERR(from))
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return PTR_ERR(from);
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to = getname(newname);
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error = PTR_ERR(to);
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if (!IS_ERR(to)) {
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struct dentry *dentry;
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struct nameidata nd;
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if (IS_ERR(to))
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goto out_putname;
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error = do_path_lookup(newdfd, to, LOOKUP_PARENT, &nd);
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if (error)
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goto out;
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dentry = lookup_create(&nd, 0);
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error = PTR_ERR(dentry);
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if (!IS_ERR(dentry)) {
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error = vfs_symlink(nd.dentry->d_inode, dentry, from, S_IALLUGO);
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dput(dentry);
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}
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mutex_unlock(&nd.dentry->d_inode->i_mutex);
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path_release(&nd);
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error = do_path_lookup(newdfd, to, LOOKUP_PARENT, &nd);
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if (error)
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goto out;
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dentry = lookup_create(&nd, 0);
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error = PTR_ERR(dentry);
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if (IS_ERR(dentry))
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goto out_unlock;
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error = vfs_symlink(nd.dentry->d_inode, dentry, from, S_IALLUGO);
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dput(dentry);
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out_unlock:
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mutex_unlock(&nd.dentry->d_inode->i_mutex);
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path_release(&nd);
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out:
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putname(to);
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}
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putname(to);
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out_putname:
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putname(from);
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return error;
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}
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@ -2308,10 +2314,11 @@ asmlinkage long sys_linkat(int olddfd, const char __user *oldname,
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goto out_release;
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new_dentry = lookup_create(&nd, 0);
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error = PTR_ERR(new_dentry);
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if (!IS_ERR(new_dentry)) {
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error = vfs_link(old_nd.dentry, nd.dentry->d_inode, new_dentry);
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dput(new_dentry);
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}
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if (IS_ERR(new_dentry))
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goto out_unlock;
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error = vfs_link(old_nd.dentry, nd.dentry->d_inode, new_dentry);
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dput(new_dentry);
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out_unlock:
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mutex_unlock(&nd.dentry->d_inode->i_mutex);
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out_release:
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path_release(&nd);
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64
fs/open.c
64
fs/open.c
@ -386,15 +386,21 @@ asmlinkage long sys_faccessat(int dfd, const char __user *filename, int mode)
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current->cap_effective = current->cap_permitted;
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res = __user_walk_fd(dfd, filename, LOOKUP_FOLLOW|LOOKUP_ACCESS, &nd);
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if (!res) {
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res = vfs_permission(&nd, mode);
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/* SuS v2 requires we report a read only fs too */
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if(!res && (mode & S_IWOTH) && IS_RDONLY(nd.dentry->d_inode)
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&& !special_file(nd.dentry->d_inode->i_mode))
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res = -EROFS;
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path_release(&nd);
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}
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if (res)
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goto out;
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res = vfs_permission(&nd, mode);
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/* SuS v2 requires we report a read only fs too */
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if(res || !(mode & S_IWOTH) ||
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special_file(nd.dentry->d_inode->i_mode))
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goto out_path_release;
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if(IS_RDONLY(nd.dentry->d_inode))
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res = -EROFS;
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out_path_release:
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path_release(&nd);
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out:
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current->fsuid = old_fsuid;
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current->fsgid = old_fsgid;
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current->cap_effective = old_cap;
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@ -603,10 +609,11 @@ asmlinkage long sys_chown(const char __user * filename, uid_t user, gid_t group)
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int error;
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error = user_path_walk(filename, &nd);
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if (!error) {
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error = chown_common(nd.dentry, user, group);
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path_release(&nd);
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}
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if (error)
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goto out;
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error = chown_common(nd.dentry, user, group);
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path_release(&nd);
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out:
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return error;
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}
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@ -622,10 +629,10 @@ asmlinkage long sys_fchownat(int dfd, const char __user *filename, uid_t user,
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follow = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW;
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error = __user_walk_fd(dfd, filename, follow, &nd);
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if (!error) {
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error = chown_common(nd.dentry, user, group);
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path_release(&nd);
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}
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if (error)
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goto out;
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error = chown_common(nd.dentry, user, group);
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path_release(&nd);
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out:
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return error;
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}
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@ -636,10 +643,11 @@ asmlinkage long sys_lchown(const char __user * filename, uid_t user, gid_t group
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int error;
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error = user_path_walk_link(filename, &nd);
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if (!error) {
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error = chown_common(nd.dentry, user, group);
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path_release(&nd);
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}
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if (error)
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goto out;
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error = chown_common(nd.dentry, user, group);
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path_release(&nd);
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out:
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return error;
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}
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@ -648,15 +656,17 @@ asmlinkage long sys_fchown(unsigned int fd, uid_t user, gid_t group)
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{
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struct file * file;
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int error = -EBADF;
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struct dentry * dentry;
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file = fget(fd);
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if (file) {
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struct dentry * dentry;
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dentry = file->f_dentry;
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audit_inode(NULL, dentry->d_inode);
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error = chown_common(dentry, user, group);
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fput(file);
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}
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if (!file)
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goto out;
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dentry = file->f_dentry;
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audit_inode(NULL, dentry->d_inode);
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error = chown_common(dentry, user, group);
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fput(file);
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out:
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return error;
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}
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