From 0c93b7d85d40b690f04786ea0f18798b73182e4f Mon Sep 17 00:00:00 2001 From: Al Viro Date: Fri, 25 Mar 2016 12:06:51 -0400 Subject: [PATCH] bpf: reject invalid names right in ->lookup() ... and other methods won't see them at all Signed-off-by: Al Viro --- kernel/bpf/inode.c | 37 ++++++++----------------------------- 1 file changed, 8 insertions(+), 29 deletions(-) diff --git a/kernel/bpf/inode.c b/kernel/bpf/inode.c index f2ece3c174a5..35d21c189bb0 100644 --- a/kernel/bpf/inode.c +++ b/kernel/bpf/inode.c @@ -119,18 +119,10 @@ static int bpf_inode_type(const struct inode *inode, enum bpf_type *type) return 0; } -static bool bpf_dname_reserved(const struct dentry *dentry) -{ - return strchr(dentry->d_name.name, '.'); -} - static int bpf_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) { struct inode *inode; - if (bpf_dname_reserved(dentry)) - return -EPERM; - inode = bpf_get_inode(dir->i_sb, dir, mode | S_IFDIR); if (IS_ERR(inode)) return PTR_ERR(inode); @@ -152,9 +144,6 @@ static int bpf_mkobj_ops(struct inode *dir, struct dentry *dentry, { struct inode *inode; - if (bpf_dname_reserved(dentry)) - return -EPERM; - inode = bpf_get_inode(dir->i_sb, dir, mode | S_IFREG); if (IS_ERR(inode)) return PTR_ERR(inode); @@ -187,31 +176,21 @@ static int bpf_mkobj(struct inode *dir, struct dentry *dentry, umode_t mode, } } -static int bpf_link(struct dentry *old_dentry, struct inode *dir, - struct dentry *new_dentry) +static struct dentry * +bpf_lookup(struct inode *dir, struct dentry *dentry, unsigned flags) { - if (bpf_dname_reserved(new_dentry)) - return -EPERM; - - return simple_link(old_dentry, dir, new_dentry); -} - -static int bpf_rename(struct inode *old_dir, struct dentry *old_dentry, - struct inode *new_dir, struct dentry *new_dentry) -{ - if (bpf_dname_reserved(new_dentry)) - return -EPERM; - - return simple_rename(old_dir, old_dentry, new_dir, new_dentry); + if (strchr(dentry->d_name.name, '.')) + return ERR_PTR(-EPERM); + return simple_lookup(dir, dentry, flags); } static const struct inode_operations bpf_dir_iops = { - .lookup = simple_lookup, + .lookup = bpf_lookup, .mknod = bpf_mkobj, .mkdir = bpf_mkdir, .rmdir = simple_rmdir, - .rename = bpf_rename, - .link = bpf_link, + .rename = simple_rename, + .link = simple_link, .unlink = simple_unlink, }; -- 2.30.2