From f9524e6f5447277e238b419afc3d0712941fa2a5 Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Thu, 5 Feb 2015 20:11:41 +0100 Subject: [PATCH] x86/microcode/intel: Do the mc_saved_src NULL check first ... and only then deref it. Also, shorten some variable names and rename others so as to diminish the ubiquitous presence of the "mc_" prefix everywhere and make it a bit more readable. Use kcalloc so that we don't kfree() uninitialized memory on the unwind path, as suggested by Quentin. Signed-off-by: Borislav Petkov Cc: Quentin Casasnovas --- arch/x86/kernel/cpu/microcode/intel_early.c | 38 ++++++++++++--------- 1 file changed, 22 insertions(+), 16 deletions(-) diff --git a/arch/x86/kernel/cpu/microcode/intel_early.c b/arch/x86/kernel/cpu/microcode/intel_early.c index d515ff3feb8b..95516006958d 100644 --- a/arch/x86/kernel/cpu/microcode/intel_early.c +++ b/arch/x86/kernel/cpu/microcode/intel_early.c @@ -203,7 +203,7 @@ save_microcode(struct mc_saved_data *mc_saved_data, unsigned int mc_saved_count) { int i, j; - struct microcode_intel **mc_saved_p; + struct microcode_intel **saved_ptr; int ret; if (!mc_saved_count) @@ -212,39 +212,45 @@ save_microcode(struct mc_saved_data *mc_saved_data, /* * Copy new microcode data. */ - mc_saved_p = kmalloc(mc_saved_count*sizeof(struct microcode_intel *), - GFP_KERNEL); - if (!mc_saved_p) + saved_ptr = kcalloc(mc_saved_count, sizeof(struct microcode_intel *), GFP_KERNEL); + if (!saved_ptr) return -ENOMEM; for (i = 0; i < mc_saved_count; i++) { - struct microcode_intel *mc = mc_saved_src[i]; - struct microcode_header_intel *mc_header = &mc->hdr; - unsigned long mc_size = get_totalsize(mc_header); - mc_saved_p[i] = kmalloc(mc_size, GFP_KERNEL); - if (!mc_saved_p[i]) { - ret = -ENOMEM; - goto err; - } + struct microcode_header_intel *mc_hdr; + struct microcode_intel *mc; + unsigned long size; + if (!mc_saved_src[i]) { ret = -EINVAL; goto err; } - memcpy(mc_saved_p[i], mc, mc_size); + + mc = mc_saved_src[i]; + mc_hdr = &mc->hdr; + size = get_totalsize(mc_hdr); + + saved_ptr[i] = kmalloc(size, GFP_KERNEL); + if (!saved_ptr[i]) { + ret = -ENOMEM; + goto err; + } + + memcpy(saved_ptr[i], mc, size); } /* * Point to newly saved microcode. */ - mc_saved_data->mc_saved = mc_saved_p; + mc_saved_data->mc_saved = saved_ptr; mc_saved_data->mc_saved_count = mc_saved_count; return 0; err: for (j = 0; j <= i; j++) - kfree(mc_saved_p[j]); - kfree(mc_saved_p); + kfree(saved_ptr[j]); + kfree(saved_ptr); return ret; } -- 2.39.5