From: "Maciej S. Szmigiero" <mail@maciej.szmigiero.name>
To: Borislav Petkov <bp@alien8.de>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
x86@kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v3 7/9] x86/microcode/AMD: check microcode container file size before accessing it
Date: Tue, 13 Mar 2018 22:07:10 +0100 [thread overview]
Message-ID: <4acc25d2-cd24-d445-2bd8-50512f0e8a39@maciej.szmigiero.name> (raw)
In-Reply-To: <cover.1520973389.git.mail@maciej.szmigiero.name>
The early loader parse_container() function should check whether the
microcode container file is actually large enough to contain the patch of
an indicated size, just like the late loader does.
Also, the request_microcode_amd() function should check whether the
container file is actually large enough to contain the header magic value.
Signed-off-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
---
arch/x86/kernel/cpu/microcode/amd.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
index 3ad23e72c2b0..63bd1a63f98a 100644
--- a/arch/x86/kernel/cpu/microcode/amd.c
+++ b/arch/x86/kernel/cpu/microcode/amd.c
@@ -137,6 +137,9 @@ static size_t parse_container(u8 *ucode, size_t size, struct cont_desc *desc)
struct microcode_amd *mc;
u32 patch_size;
+ if (size < SECTION_HDR_SIZE)
+ break;
+
hdr = (u32 *)buf;
if (hdr[0] != UCODE_UCODE_TYPE)
@@ -151,6 +154,10 @@ static size_t parse_container(u8 *ucode, size_t size, struct cont_desc *desc)
buf += SECTION_HDR_SIZE;
size -= SECTION_HDR_SIZE;
+ if (size < sizeof(*mc) ||
+ size < patch_size)
+ break;
+
mc = (struct microcode_amd *)buf;
if (eq_id == mc->hdr.processor_rev_id) {
desc->psize = patch_size;
@@ -786,6 +793,10 @@ static enum ucode_state request_microcode_amd(int cpu, struct device *device,
}
ret = UCODE_ERROR;
+ if (fw->size < sizeof(u32)) {
+ pr_err("microcode container far too short\n");
+ goto fw_release;
+ }
if (*(u32 *)fw->data != UCODE_MAGIC) {
pr_err("invalid magic value (0x%08x)\n", *(u32 *)fw->data);
goto fw_release;
next prev parent reply other threads:[~2018-03-13 21:07 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <cover.1520973389.git.mail@maciej.szmigiero.name>
2018-03-13 21:06 ` [PATCH v3 1/9] x86/microcode/AMD: subtract SECTION_HDR_SIZE from file leftover length Maciej S. Szmigiero
2018-03-14 12:38 ` Borislav Petkov
2018-03-13 21:06 ` [PATCH v3 2/9] x86/microcode/AMD: check whether the equivalence table fits in the file Maciej S. Szmigiero
2018-03-14 17:04 ` Borislav Petkov
2018-03-14 23:34 ` Maciej S. Szmigiero
2018-03-15 10:42 ` Borislav Petkov
2018-03-13 21:06 ` [PATCH v3 3/9] x86/microcode/AMD: install_equiv_cpu_table() should not return (signed) int Maciej S. Szmigiero
2018-03-14 17:58 ` Borislav Petkov
2018-03-14 23:46 ` Maciej S. Szmigiero
2018-03-14 23:58 ` Borislav Petkov
2018-03-15 0:13 ` Maciej S. Szmigiero
2018-03-15 0:56 ` Borislav Petkov
2018-03-15 0:59 ` Maciej S. Szmigiero
2018-03-13 21:06 ` [PATCH v3 4/9] x86/microcode/AMD: automatically compute the PATCH_MAX_SIZE macro Maciej S. Szmigiero
2018-03-14 18:02 ` Borislav Petkov
2018-03-15 0:05 ` Maciej S. Szmigiero
2018-03-15 1:00 ` Borislav Petkov
2018-03-13 21:06 ` [PATCH v3 5/9] x86/microcode/AMD: check patch size in verify_and_add_patch() Maciej S. Szmigiero
2018-03-13 21:07 ` [PATCH v3 6/9] x86/microcode/AMD: verify patch section type for every such section Maciej S. Szmigiero
2018-03-15 16:31 ` Borislav Petkov
2018-03-13 21:07 ` Maciej S. Szmigiero [this message]
2018-03-13 21:07 ` [PATCH v3 8/9] x86/microcode/AMD: check the equivalence table size when scanning it Maciej S. Szmigiero
2018-03-13 21:07 ` [PATCH v3 9/9] x86/microcode/AMD: be more tolerant of late parse failures in late loader Maciej S. Szmigiero
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