[PATCH 1/2] module: Pass struct load_info into symbol checks

[Kees Cook]

Since we're already using values from struct load_info, just pass this
pointer in directly and use what's needed as we need it. This allows us
to access future fields in struct load_info too.

Signed-off-by: Kees Cook <keesc...@chromium.org>
---
 kernel/module.c | 22 ++++++++++------------
 1 file changed, 10 insertions(+), 12 deletions(-)

diff --git a/kernel/module.c b/kernel/module.c
index 7eba6dea4f41..ed6cf2367217 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1257,12 +1257,13 @@ static u32 resolve_rel_crc(const s32 *crc)
        return *(u32 *)((void *)crc + *crc);
 }
 
-static int check_version(Elf_Shdr *sechdrs,
-                        unsigned int versindex,
+static int check_version(const struct load_info *info,
                         const char *symname,
                         struct module *mod,
                         const s32 *crc)
 {
+       Elf_Shdr *sechdrs = info->sechdrs;
+       unsigned int versindex = info->index.vers;
        unsigned int i, num_versions;
        struct modversion_info *versions;
 
@@ -1305,8 +1306,7 @@ static int check_version(Elf_Shdr *sechdrs,
        return 0;
 }
 
-static inline int check_modstruct_version(Elf_Shdr *sechdrs,
-                                         unsigned int versindex,
+static inline int check_modstruct_version(const struct load_info *info,
                                          struct module *mod)
 {
        const s32 *crc;
@@ -1322,8 +1322,8 @@ static inline int check_modstruct_version(Elf_Shdr 
*sechdrs,
                BUG();
        }
        preempt_enable();
-       return check_version(sechdrs, versindex,
-                            VMLINUX_SYMBOL_STR(module_layout), mod, crc);
+       return check_version(info, VMLINUX_SYMBOL_STR(module_layout),
+                            mod, crc);
 }
 
 /* First part is kernel version, which we ignore if module has crcs. */
@@ -1337,8 +1337,7 @@ static inline int same_magic(const char *amagic, const 
char *bmagic,
        return strcmp(amagic, bmagic) == 0;
 }
 #else
-static inline int check_version(Elf_Shdr *sechdrs,
-                               unsigned int versindex,
+static inline int check_version(const struct load_info *info,
                                const char *symname,
                                struct module *mod,
                                const s32 *crc)
@@ -1346,8 +1345,7 @@ static inline int check_version(Elf_Shdr *sechdrs,
        return 1;
 }
 
-static inline int check_modstruct_version(Elf_Shdr *sechdrs,
-                                         unsigned int versindex,
+static inline int check_modstruct_version(const struct load_info *info,
                                          struct module *mod)
 {
        return 1;
@@ -1383,7 +1381,7 @@ static const struct kernel_symbol *resolve_symbol(struct 
module *mod,
        if (!sym)
                goto unlock;
 
-       if (!check_version(info->sechdrs, info->index.vers, name, mod, crc)) {
+       if (!check_version(info, name, mod, crc)) {
                sym = ERR_PTR(-EINVAL);
                goto getname;
        }
@@ -2950,7 +2948,7 @@ static struct module *setup_load_info(struct load_info 
*info, int flags)
        info->index.pcpu = find_pcpusec(info);
 
        /* Check module struct version now, before we try to use module. */
-       if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
+       if (!check_modstruct_version(info, mod))
                return ERR_PTR(-ENOEXEC);
 
        return mod;
-- 
2.7.4