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authorBorislav Petkov <bp@suse.de>2022-12-19 22:06:56 +0100
committerBorislav Petkov (AMD) <bp@alien8.de>2022-12-26 06:41:05 +0100
commitba73e369b706a853cdafa60570854fecec9f9fdd (patch)
treedf0719b9f157101112b315aaeb636dc11e10c366 /arch/x86/kernel/cpu/microcode
parent61de9b7036f26448a1916291c456f62dd6bf07ea (diff)
x86/microcode/AMD: Handle multiple glued containers properly
It can happen that - especially during testing - the microcode blobs of all families are all glued together in the initrd. The current code doesn't check whether the current container matched a microcode patch and continues to the next one, which leads to save_microcode_in_initrd_amd() to look at the next and thus wrong one: microcode: parse_container: ucode: 0xffff88807e9d9082 microcode: verify_patch: buf: 0xffff88807e9d90ce, buf_size: 26428 microcode: verify_patch: proc_id: 0x8082, patch_fam: 0x17, this family: 0x17 microcode: verify_patch: buf: 0xffff88807e9d9d56, buf_size: 23220 microcode: verify_patch: proc_id: 0x8012, patch_fam: 0x17, this family: 0x17 microcode: parse_container: MATCH: eq_id: 0x8012, patch proc_rev_id: 0x8012 <-- matching patch found microcode: verify_patch: buf: 0xffff88807e9da9de, buf_size: 20012 microcode: verify_patch: proc_id: 0x8310, patch_fam: 0x17, this family: 0x17 microcode: verify_patch: buf: 0xffff88807e9db666, buf_size: 16804 microcode: Invalid type field (0x414d44) in container file section header. microcode: Patch section fail <-- checking chokes on the microcode magic value of the next container. microcode: parse_container: saving container 0xffff88807e9d9082 microcode: save_microcode_in_initrd_amd: scanned containers, data: 0xffff88807e9d9082, size: 9700a and now if there's a next (and last container) it'll use that in save_microcode_in_initrd_amd() and not find a proper patch, ofc. Fix that by moving the out: label up, before the desc->mc check which jots down the pointer of the matching patch and is used to signal to the caller that it has found a matching patch in the current container. Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20221219210656.5140-2-bp@alien8.de
Diffstat (limited to 'arch/x86/kernel/cpu/microcode')
-rw-r--r--arch/x86/kernel/cpu/microcode/amd.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
index 339c9666c8bc..d144f918a896 100644
--- a/arch/x86/kernel/cpu/microcode/amd.c
+++ b/arch/x86/kernel/cpu/microcode/amd.c
@@ -330,8 +330,9 @@ static size_t parse_container(u8 *ucode, size_t size, struct cont_desc *desc)
ret = verify_patch(x86_family(desc->cpuid_1_eax), buf, size, &patch_size, true);
if (ret < 0) {
/*
- * Patch verification failed, skip to the next
- * container, if there's one:
+ * Patch verification failed, skip to the next container, if
+ * there is one. Before exit, check whether that container has
+ * found a patch already. If so, use it.
*/
goto out;
} else if (ret > 0) {
@@ -350,6 +351,7 @@ skip:
size -= patch_size + SECTION_HDR_SIZE;
}
+out:
/*
* If we have found a patch (desc->mc), it means we're looking at the
* container which has a patch for this CPU so return 0 to mean, @ucode
@@ -364,7 +366,6 @@ skip:
return 0;
}
-out:
return orig_size - size;
}