verify_patch_size() function verifies whether the microcode container file
remaining size is large enough to contain a patch of the indicated size.
However, the section header length is not included in this indicated size
but it is present in the leftover file length so it should be subtracted
from the leftover file length before passing this value to
verify_patch_size().
Signed-off-by: Maciej S. Szmigiero <[email protected]>
---
arch/x86/kernel/cpu/microcode/amd.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
index a998e1a7d46f..6a93be0f771c 100644
--- a/arch/x86/kernel/cpu/microcode/amd.c
+++ b/arch/x86/kernel/cpu/microcode/amd.c
@@ -613,7 +613,16 @@ static int verify_and_add_patch(u8 family, u8 *fw, unsigned int leftover)
return crnt_size;
}
- ret = verify_patch_size(family, patch_size, leftover);
+ /*
+ * verify_patch_size() checks whether the passed remaining file size
+ * is large enough to contain a patch of the indicated size (and also
+ * whether this size does not exceed the family maximum).
+ *
+ * The section header length is not included in this indicated size
+ * but it is present in the leftover file length so we need to subtract
+ * it before passing this value to that function.
+ */
+ ret = verify_patch_size(family, patch_size, leftover - SECTION_HDR_SIZE);
if (!ret) {
pr_err("Patch-ID 0x%08x: size mismatch.\n", mc_hdr->patch_id);
return crnt_size;
On Fri, Mar 16, 2018 at 12:07:42AM +0100, Maciej S. Szmigiero wrote:
> verify_patch_size() function verifies whether the microcode container file
> remaining size is large enough to contain a patch of the indicated size.
>
> However, the section header length is not included in this indicated size
> but it is present in the leftover file length so it should be subtracted
> from the leftover file length before passing this value to
> verify_patch_size().
>
> Signed-off-by: Maciej S. Szmigiero <[email protected]>
> ---
> arch/x86/kernel/cpu/microcode/amd.c | 11 ++++++++++-
> 1 file changed, 10 insertions(+), 1 deletion(-)
I split the comment and applied this:
---
From: "Maciej S. Szmigiero" <[email protected]>
Date: Fri, 16 Mar 2018 00:07:42 +0100
Subject: [PATCH] x86/microcode/AMD: Subtract SECTION_HDR_SIZE from file
leftover length
verify_patch_size() verifies whether the remaining size of the microcode
container file is large enough to contain a patch of the indicated size.
However, the section header length is not included in this indicated
size but it is present in the leftover file length so it should be
subtracted from the leftover file length before passing this value to
verify_patch_size().
Signed-off-by: Maciej S. Szmigiero <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
[ Split comment. ]
Signed-off-by: Borislav Petkov <[email protected]>
---
arch/x86/kernel/cpu/microcode/amd.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
index 48179928ff38..ffce949409cc 100644
--- a/arch/x86/kernel/cpu/microcode/amd.c
+++ b/arch/x86/kernel/cpu/microcode/amd.c
@@ -461,8 +461,12 @@ static int collect_cpu_info_amd(int cpu, struct cpu_signature *csig)
return 0;
}
-static unsigned int verify_patch_size(u8 family, u32 patch_size,
- unsigned int size)
+/*
+ * Check whether the passed remaining file @size is large enough to contain a
+ * patch of the indicated @patch_size (and also whether this size does not
+ * exceed the per-family maximum).
+ */
+static unsigned int verify_patch_size(u8 family, u32 patch_size, unsigned int size)
{
u32 max_size;
@@ -613,7 +617,12 @@ static int verify_and_add_patch(u8 family, u8 *fw, unsigned int leftover)
return crnt_size;
}
- ret = verify_patch_size(family, patch_size, leftover);
+ /*
+ * The section header length is not included in this indicated size
+ * but is present in the leftover file length so we need to subtract
+ * it before passing this value to the function below.
+ */
+ ret = verify_patch_size(family, patch_size, leftover - SECTION_HDR_SIZE);
if (!ret) {
pr_err("Patch-ID 0x%08x: size mismatch.\n", mc_hdr->patch_id);
return crnt_size;
--
2.7.3
--
Regards/Gruss,
Boris.
ECO tip #101: Trim your mails when you reply. Srsly.
On 18.03.2018 17:12, Borislav Petkov wrote:
> On Fri, Mar 16, 2018 at 12:07:42AM +0100, Maciej S. Szmigiero wrote:
>> verify_patch_size() function verifies whether the microcode container file
>> remaining size is large enough to contain a patch of the indicated size.
>>
>> However, the section header length is not included in this indicated size
>> but it is present in the leftover file length so it should be subtracted
>> from the leftover file length before passing this value to
>> verify_patch_size().
>>
>> Signed-off-by: Maciej S. Szmigiero <[email protected]>
>> ---
>> arch/x86/kernel/cpu/microcode/amd.c | 11 ++++++++++-
>> 1 file changed, 10 insertions(+), 1 deletion(-)
>
> I split the comment and applied this:
>
> ---
> From: "Maciej S. Szmigiero" <[email protected]>
> Date: Fri, 16 Mar 2018 00:07:42 +0100
> Subject: [PATCH] x86/microcode/AMD: Subtract SECTION_HDR_SIZE from file
> leftover length
Can't really find this commit in any tree I have looked at (bp.git and
tip.git at kernel.org).
Was it pushed somewhere else?
Maciej
On Wed, Apr 18, 2018 at 02:39:27PM +0200, Maciej S. Szmigiero wrote:
> Can't really find this commit in any tree I have looked at (bp.git and
> tip.git at kernel.org).
> Was it pushed somewhere else?
No. Still waiting for the rest.
--
Regards/Gruss,
Boris.
Good mailing practices for 400: avoid top-posting and trim the reply.
On 18.04.2018 15:53, Borislav Petkov wrote:
> On Wed, Apr 18, 2018 at 02:39:27PM +0200, Maciej S. Szmigiero wrote:
>> Can't really find this commit in any tree I have looked at (bp.git and
>> tip.git at kernel.org).
>> Was it pushed somewhere else?
>
> No. Still waiting for the rest.
>
So, should this patch be included in a respin or not?
Maciej
On Wed, Apr 18, 2018 at 03:57:23PM +0200, Maciej S. Szmigiero wrote:
> So, should this patch be included in a respin or not?
Yes please. Do them all ontop of tip/master.
--
Regards/Gruss,
Boris.
Good mailing practices for 400: avoid top-posting and trim the reply.