[PATCH v2 1/6] s390/kexec_file: Don't opencode appended signature check.
From: Michal Suchanek <hidden>
Date: 2021-11-25 18:05:42
Also in:
kexec, keyrings, linux-crypto, linux-integrity, linux-security-module, linuxppc-dev, lkml
Subsystem:
s390 architecture, the rest · Maintainers:
Heiko Carstens, Vasily Gorbik, Alexander Gordeev, Linus Torvalds
Module verification already implements appeded signature check. Reuse it for kexec_file. Signed-off-by: Michal Suchanek <redacted> --- arch/s390/kernel/machine_kexec_file.c | 22 +++++----------------- 1 file changed, 5 insertions(+), 17 deletions(-)
diff --git a/arch/s390/kernel/machine_kexec_file.c b/arch/s390/kernel/machine_kexec_file.c
index 9975ad200d74..43a9abe48abd 100644
--- a/arch/s390/kernel/machine_kexec_file.c
+++ b/arch/s390/kernel/machine_kexec_file.c@@ -29,6 +29,7 @@ int s390_verify_sig(const char *kernel, unsigned long kernel_len) const unsigned long marker_len = sizeof(MODULE_SIG_STRING) - 1; struct module_signature *ms; unsigned long sig_len; + int ret; /* Skip signature verification when not secure IPLed. */ if (!ipl_secure_flag)
@@ -43,25 +44,12 @@ int s390_verify_sig(const char *kernel, unsigned long kernel_len) kernel_len -= marker_len; ms = (void *)kernel + kernel_len - sizeof(*ms); - kernel_len -= sizeof(*ms); + ret = mod_check_sig(ms, kernel_len, "kexec"); + if (ret) + return ret; sig_len = be32_to_cpu(ms->sig_len); - if (sig_len >= kernel_len) - return -EKEYREJECTED; - kernel_len -= sig_len; - - if (ms->id_type != PKEY_ID_PKCS7) - return -EKEYREJECTED; - - if (ms->algo != 0 || - ms->hash != 0 || - ms->signer_len != 0 || - ms->key_id_len != 0 || - ms->__pad[0] != 0 || - ms->__pad[1] != 0 || - ms->__pad[2] != 0) { - return -EBADMSG; - } + kernel_len -= sizeof(*ms) + sig_len; return verify_pkcs7_signature(kernel, kernel_len, kernel + kernel_len, sig_len,
--
2.31.1