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| author | Quentin Casasnovas <quentin.casasnovas@oracle.com> | 2015-02-03 13:00:24 +0100 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2015-02-19 12:42:23 +0100 |
| commit | 35a9ff4eec7a1725ac4364972fc6c156e4feedd0 (patch) | |
| tree | d77433b391eb3f7e9f85d46b720af0cd17be85f7 /arch/x86 | |
| parent | f84598bd7c851f8b0bf8cd0d7c3be0d73c432ff4 (diff) | |
| download | linux-35a9ff4eec7a1725ac4364972fc6c156e4feedd0.tar.bz2 | |
x86/microcode/intel: Handle truncated microcode images more robustly
We do not check the input data bounds containing the microcode before
copying a struct microcode_intel_header from it. A specially crafted
microcode could cause the kernel to read invalid memory and lead to a
denial-of-service.
Signed-off-by: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1422964824-22056-3-git-send-email-quentin.casasnovas@oracle.com
[ Made error message differ from the next one and flipped comparison. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kernel/cpu/microcode/intel.c | 5 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/microcode/intel_early.c | 4 |
2 files changed, 9 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c index c6826d1e8082..746e7fd08aad 100644 --- a/arch/x86/kernel/cpu/microcode/intel.c +++ b/arch/x86/kernel/cpu/microcode/intel.c @@ -196,6 +196,11 @@ static enum ucode_state generic_load_microcode(int cpu, void *data, size_t size, struct microcode_header_intel mc_header; unsigned int mc_size; + if (leftover < sizeof(mc_header)) { + pr_err("error! Truncated header in microcode data file\n"); + break; + } + if (get_ucode_data(&mc_header, ucode_ptr, sizeof(mc_header))) break; diff --git a/arch/x86/kernel/cpu/microcode/intel_early.c b/arch/x86/kernel/cpu/microcode/intel_early.c index 5e109a31f62b..420eb933189c 100644 --- a/arch/x86/kernel/cpu/microcode/intel_early.c +++ b/arch/x86/kernel/cpu/microcode/intel_early.c @@ -322,6 +322,10 @@ get_matching_model_microcode(int cpu, unsigned long start, int i; while (leftover && mc_saved_count < ARRAY_SIZE(mc_saved_tmp)) { + + if (leftover < sizeof(mc_header)) + break; + mc_header = (struct microcode_header_intel *)ucode_ptr; mc_size = get_totalsize(mc_header); |