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| author | Ben Hutchings <ben@decadent.org.uk> | 2016-04-28 09:24:01 +0930 |
|---|---|---|
| committer | Sasha Levin <alexander.levin@verizon.com> | 2016-08-19 23:07:58 -0400 |
| commit | 6ac9857245bfb71d836f46db817b0c11e3e4bf69 (patch) | |
| tree | 7d9e37d7adeb4599c25e712f816f4c50d1f261d2 /kernel | |
| parent | 7e6f0e1e3091dc9aada9d067aac7adbb5a9d9b06 (diff) | |
| download | lwn-6ac9857245bfb71d836f46db817b0c11e3e4bf69.tar.gz lwn-6ac9857245bfb71d836f46db817b0c11e3e4bf69.zip | |
module: Invalidate signatures on force-loaded modules
[ Upstream commit bca014caaa6130e57f69b5bf527967aa8ee70fdd ]
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: Ben Hutchings <ben@decadent.org.uk>
Cc: stable@vger.kernel.org
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/module.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/kernel/module.c b/kernel/module.c index be8971d817ed..6920d1080cdd 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -2451,13 +2451,18 @@ 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; @@ -2476,7 +2481,7 @@ 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; } @@ -3277,7 +3282,7 @@ 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; |