It is stripped by each caller separately.

Signed-off-by: Michal Suchanek <msucha...@suse.de>
---
 arch/powerpc/kexec/elf_64.c           |  9 ---------
 arch/s390/kernel/machine_kexec_file.c |  9 ---------
 kernel/module.c                       |  7 +------
 kernel/module_signing.c               | 12 ++++++++++--
 4 files changed, 11 insertions(+), 26 deletions(-)

diff --git a/arch/powerpc/kexec/elf_64.c b/arch/powerpc/kexec/elf_64.c
index 266cb26d3ca0..63634c95265d 100644
--- a/arch/powerpc/kexec/elf_64.c
+++ b/arch/powerpc/kexec/elf_64.c
@@ -156,15 +156,6 @@ static void *elf64_load(struct kimage *image, char 
*kernel_buf,
 int elf64_verify_sig(const char *kernel, unsigned long length)
 {
        size_t kernel_len = length;
-       const unsigned long marker_len = sizeof(MODULE_SIG_STRING) - 1;
-
-       if (marker_len > kernel_len)
-               return -EKEYREJECTED;
-
-       if (memcmp(kernel + kernel_len - marker_len, MODULE_SIG_STRING,
-                  marker_len))
-               return -EKEYREJECTED;
-       kernel_len -= marker_len;
 
        return verify_appended_signature(kernel, &kernel_len, 
VERIFY_USE_PLATFORM_KEYRING,
                                        "kexec_file");
diff --git a/arch/s390/kernel/machine_kexec_file.c 
b/arch/s390/kernel/machine_kexec_file.c
index 432797249db3..c4632c1a1b59 100644
--- a/arch/s390/kernel/machine_kexec_file.c
+++ b/arch/s390/kernel/machine_kexec_file.c
@@ -27,20 +27,11 @@ const struct kexec_file_ops * const kexec_file_loaders[] = {
 int s390_verify_sig(const char *kernel, unsigned long length)
 {
        size_t kernel_len = length;
-       const unsigned long marker_len = sizeof(MODULE_SIG_STRING) - 1;
 
        /* Skip signature verification when not secure IPLed. */
        if (!ipl_secure_flag)
                return 0;
 
-       if (marker_len > kernel_len)
-               return -EKEYREJECTED;
-
-       if (memcmp(kernel + kernel_len - marker_len, MODULE_SIG_STRING,
-                  marker_len))
-               return -EKEYREJECTED;
-       kernel_len -= marker_len;
-
        return verify_appended_signature(kernel, &kernel_len, 
VERIFY_USE_PLATFORM_KEYRING,
                                        "kexec_file");
 }
diff --git a/kernel/module.c b/kernel/module.c
index 8481933dfa92..d91ca0f93a40 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -2882,7 +2882,6 @@ static inline void kmemleak_load_module(const struct 
module *mod,
 static int module_sig_check(struct load_info *info, int flags)
 {
        int err = -ENODATA;
-       const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
        const char *reason;
        const void *mod = info->hdr;
 
@@ -2890,11 +2889,7 @@ static int module_sig_check(struct load_info *info, int 
flags)
         * 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;
+       if (flags == 0) {
                err = verify_appended_signature(mod, &info->len,
                                                VERIFY_USE_SECONDARY_KEYRING, 
"module");
                if (!err) {
diff --git a/kernel/module_signing.c b/kernel/module_signing.c
index f492e410564d..4c28cb55275f 100644
--- a/kernel/module_signing.c
+++ b/kernel/module_signing.c
@@ -15,8 +15,7 @@
 #include "module-internal.h"
 
 /**
- * verify_appended_signature - Verify the signature on a module with the
- * signature marker stripped.
+ * verify_appended_signature - Verify the signature on a module
  * @data: The data to be verified
  * @len: Size of @data.
  * @trusted_keys: Keyring to use for verification
@@ -25,12 +24,21 @@
 int verify_appended_signature(const void *data, size_t *len,
                              struct key *trusted_keys, const char *what)
 {
+       const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
        struct module_signature ms;
        size_t sig_len, modlen = *len;
        int ret;
 
        pr_devel("==>%s(,%zu)\n", __func__, modlen);
 
+       if (markerlen > modlen)
+               return -ENODATA;
+
+       if (memcmp(data + modlen - markerlen, MODULE_SIG_STRING,
+                  markerlen))
+               return -ENODATA;
+       modlen -= markerlen;
+
        if (modlen <= sizeof(ms))
                return -EBADMSG;
 
-- 
2.31.1


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