Commit bca014ca authored by Ben Hutchings's avatar Ben Hutchings Committed by Rusty Russell

module: Invalidate signatures on force-loaded modules

Signing a module should only make it trusted by the specific kernel it
was built for, not anything else.  Loading a signed module meant for a
kernel with a different ABI could have interesting effects.
Therefore, treat all signatures as invalid when a module is
force-loaded.
Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
parent 3205c36c
......@@ -2686,13 +2686,18 @@ static inline void kmemleak_load_module(const struct module *mod,
#endif
#ifdef CONFIG_MODULE_SIG
static int module_sig_check(struct load_info *info)
static int module_sig_check(struct load_info *info, int flags)
{
int err = -ENOKEY;
const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
const void *mod = info->hdr;
if (info->len > markerlen &&
/*
* Require flags == 0, as a module with version information
* removed is no longer the module that was signed
*/
if (flags == 0 &&
info->len > markerlen &&
memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
/* We truncate the module to discard the signature */
info->len -= markerlen;
......@@ -2711,7 +2716,7 @@ static int module_sig_check(struct load_info *info)
return err;
}
#else /* !CONFIG_MODULE_SIG */
static int module_sig_check(struct load_info *info)
static int module_sig_check(struct load_info *info, int flags)
{
return 0;
}
......@@ -3506,7 +3511,7 @@ static int load_module(struct load_info *info, const char __user *uargs,
long err;
char *after_dashes;
err = module_sig_check(info);
err = module_sig_check(info, flags);
if (err)
goto free_copy;
......
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