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authorKees Cook <keescook@chromium.org>2022-05-11 00:46:26 +0200
committerKees Cook <keescook@chromium.org>2022-05-17 01:02:21 +0200
commitb146cbf2e32f01f56244d670aef2f43d44fcf120 (patch)
treea6bcf259999645c5e3cea50c6a3d1df5506c7bd5
parentniu: Silence randstruct warnings (diff)
downloadlinux-b146cbf2e32f01f56244d670aef2f43d44fcf120.tar.xz
linux-b146cbf2e32f01f56244d670aef2f43d44fcf120.zip
af_unix: Silence randstruct GCC plugin warning
While preparing for Clang randstruct support (which duplicated many of the warnings the randstruct GCC plugin warned about), one strange one remained only for the randstruct GCC plugin. Eliminating this rids the plugin of the last exception. It seems the plugin is happy to dereference individual members of a cross-struct cast, but it is upset about casting to a whole object pointer. This only manifests in one place in the kernel, so just replace the variable with individual member accesses. There is no change in executable instruction output. Drop the last exception from the randstruct GCC plugin. Cc: "David S. Miller" <davem@davemloft.net> Cc: Christoph Hellwig <hch@infradead.org> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Cong Wang <cong.wang@bytedance.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: netdev@vger.kernel.org Cc: linux-hardening@vger.kernel.org Acked-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp> Link: https://lore.kernel.org/lkml/20220511022217.58586-1-kuniyu@amazon.co.jp Acked-by: Jakub Kicinski <kuba@kernel.org> Link: https://lore.kernel.org/lkml/20220511151542.4cb3ff17@kernel.org Signed-off-by: Kees Cook <keescook@chromium.org>
-rw-r--r--net/unix/af_unix.c8
-rw-r--r--scripts/gcc-plugins/randomize_layout_plugin.c2
2 files changed, 3 insertions, 7 deletions
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index e71a312faa1e..36367e7e3e0a 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -1808,11 +1808,9 @@ static int maybe_init_creds(struct scm_cookie *scm,
static bool unix_skb_scm_eq(struct sk_buff *skb,
struct scm_cookie *scm)
{
- const struct unix_skb_parms *u = &UNIXCB(skb);
-
- return u->pid == scm->pid &&
- uid_eq(u->uid, scm->creds.uid) &&
- gid_eq(u->gid, scm->creds.gid) &&
+ return UNIXCB(skb).pid == scm->pid &&
+ uid_eq(UNIXCB(skb).uid, scm->creds.uid) &&
+ gid_eq(UNIXCB(skb).gid, scm->creds.gid) &&
unix_secdata_eq(scm, skb);
}
diff --git a/scripts/gcc-plugins/randomize_layout_plugin.c b/scripts/gcc-plugins/randomize_layout_plugin.c
index c9d345a91c41..2ca768d88a68 100644
--- a/scripts/gcc-plugins/randomize_layout_plugin.c
+++ b/scripts/gcc-plugins/randomize_layout_plugin.c
@@ -46,8 +46,6 @@ struct whitelist_entry {
};
static const struct whitelist_entry whitelist[] = {
- /* unix_skb_parms via UNIXCB() buffer */
- { "net/unix/af_unix.c", "unix_skb_parms", "char" },
{ }
};