From: Kees Cook keescook@chromium.org
stable inclusion from stable-v6.6.3 commit 2e8b4e0992e16d7967095773040cd9919171d8db category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I8LBQP
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ Upstream commit 1ee60356c2dca938362528404af95b8ef3e49b6a ]
The randstruct GCC plugin tried to discover "fake" flexible arrays to issue warnings about them in randomized structs. In the future LSM overhead reduction series, it would be legal to have a randomized struct with a 1-element array, and this should _not_ be treated as a flexible array, especially since commit df8fc4e934c1 ("kbuild: Enable -fstrict-flex-arrays=3"). Disable the 0-sized and 1-element array discovery logic in the plugin, but keep the "true" flexible array check.
Cc: KP Singh kpsingh@kernel.org Cc: linux-hardening@vger.kernel.org Reported-by: kernel test robot lkp@intel.com Closes: https://lore.kernel.org/oe-kbuild-all/202311021532.iBwuZUZ0-lkp@intel.com/ Fixes: df8fc4e934c1 ("kbuild: Enable -fstrict-flex-arrays=3") Reviewed-by: Bill Wendling morbo@google.com Acked-by: "Gustavo A. R. Silva" gustavoars@kernel.org Link: https://lore.kernel.org/r/20231104204334.work.160-kees@kernel.org Signed-off-by: Kees Cook keescook@chromium.org Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- scripts/gcc-plugins/randomize_layout_plugin.c | 10 ---------- 1 file changed, 10 deletions(-)
diff --git a/scripts/gcc-plugins/randomize_layout_plugin.c b/scripts/gcc-plugins/randomize_layout_plugin.c index 951b74ba1b24..5e5744b65f8a 100644 --- a/scripts/gcc-plugins/randomize_layout_plugin.c +++ b/scripts/gcc-plugins/randomize_layout_plugin.c @@ -273,8 +273,6 @@ static bool is_flexible_array(const_tree field) { const_tree fieldtype; const_tree typesize; - const_tree elemtype; - const_tree elemsize;
fieldtype = TREE_TYPE(field); typesize = TYPE_SIZE(fieldtype); @@ -282,20 +280,12 @@ static bool is_flexible_array(const_tree field) if (TREE_CODE(fieldtype) != ARRAY_TYPE) return false;
- elemtype = TREE_TYPE(fieldtype); - elemsize = TYPE_SIZE(elemtype); - /* size of type is represented in bits */
if (typesize == NULL_TREE && TYPE_DOMAIN(fieldtype) != NULL_TREE && TYPE_MAX_VALUE(TYPE_DOMAIN(fieldtype)) == NULL_TREE) return true;
- if (typesize != NULL_TREE && - (TREE_CONSTANT(typesize) && (!tree_to_uhwi(typesize) || - tree_to_uhwi(typesize) == tree_to_uhwi(elemsize)))) - return true; - return false; }