Hi,
I'm trying to write the check to detect the absence of commit
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit?id=51b2ee7d006a736a9126e8111d1f24e4fd0afaa6
in kernel. The pattern can be:
@err exists@
identifier namlen, dchild, dparent, exp;
position p;
statement S;
@@
compose_entry_fh(..., int namlen, ...)
{
...
if (namlen == 2) {
* dchild =@p dget_parent(dparent);
... when != dparent == exp->ex_path.dentry
} else S
...
}
But unfortunately, it matches even the fixed source. I think
that condition "... when != dparent == exp->ex_path.dentry" doesn't
work as expected. Steps to reproduce:
$ cd linux # latest master branch
$ wget
https://raw.githubusercontent.com/evdenis/cvehound/b2d109c959c299dce10274c1806406fc5653e5d0/cvehound/cve/CVE-2021-3178.cocci
$ spatch -D detect --cocci-file CVE-2021-3178.cocci fs/nfsd/nfs3xdr.c
fs/nfsd/nfs3xdr.c:935:10-11: ERROR: CVE-2021-3178
diff =
--- fs/nfsd/nfs3xdr.c
+++ /tmp/cocci-output-526900-b87df1-nfs3xdr.c
@@ -932,7 +932,6 @@ compose_entry_fh(struct nfsd3_readdirres
if (isdotent(name, namlen)) {
if (namlen == 2) {
// !!! shouldn't match because of if (dparent ==
exp->ex_path.dentry) goto out; check after
- dchild = dget_parent(dparent);
/*
* Don't return filehandle for ".." if we're at
* the filesystem or export root:
$ spatch --version
spatch version 1.1.0 compiled with OCaml version 4.11.1
Thanks,
Denis
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