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| author | Quentin Casasnovas <quentin.casasnovas@oracle.com> | 2015-02-03 13:00:22 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-07-03 19:48:09 -0700 |
| commit | 66bd44e6a5c8f24805f94d19f943301d7a7f418e (patch) | |
| tree | c6f418f9617fe143ad0ac35cf657289a95fee190 | |
| parent | 9eae8ac6ab40b896b472c526afe7847e798f4f36 (diff) | |
| download | lwn-66bd44e6a5c8f24805f94d19f943301d7a7f418e.tar.gz lwn-66bd44e6a5c8f24805f94d19f943301d7a7f418e.zip | |
x86/microcode/intel: Guard against stack overflow in the loader
commit f84598bd7c851f8b0bf8cd0d7c3be0d73c432ff4 upstream.
mc_saved_tmp is a static array allocated on the stack, we need to make
sure mc_saved_count stays within its bounds, otherwise we're overflowing
the stack in _save_mc(). A specially crafted microcode header could lead
to a kernel crash or potentially kernel execution.
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/1422964824-22056-1-git-send-email-quentin.casasnovas@oracle.com
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Sheng Yong <shengyong1@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/x86/kernel/microcode_intel_early.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kernel/microcode_intel_early.c b/arch/x86/kernel/microcode_intel_early.c index 2e9e12871c2b..a883942aee44 100644 --- a/arch/x86/kernel/microcode_intel_early.c +++ b/arch/x86/kernel/microcode_intel_early.c @@ -321,7 +321,7 @@ get_matching_model_microcode(int cpu, unsigned long start, unsigned int mc_saved_count = mc_saved_data->mc_saved_count; int i; - while (leftover) { + while (leftover && mc_saved_count < ARRAY_SIZE(mc_saved_tmp)) { mc_header = (struct microcode_header_intel *)ucode_ptr; mc_size = get_totalsize(mc_header); |