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authorLinus Torvalds <torvalds@linux-foundation.org>2022-03-21 19:58:27 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2022-03-21 19:58:27 -0700
commit8565d64430f8278bea38dab0a3ab60b4e11c71e4 (patch)
tree71be2df8795c4862d45b3e1395fedf3092f723cf /arch/x86
parentd0858cbdef50d973ca6b38c0ed0cce54cb2b6182 (diff)
parentfad278388e01e3658a356118bed8ee2c2408d280 (diff)
Merge tag 'bounds-fixes-v5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull bounds fixes from Kees Cook: "These are a handful of buffer and array bounds fixes that I've been carrying in preparation for the coming memcpy improvements and the enabling of '-Warray-bounds' globally. There are additional similar fixes in other maintainer's trees, but these ended up getting carried by me. :)" * tag 'bounds-fixes-v5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: media: omap3isp: Use struct_group() for memcpy() region tpm: vtpm_proxy: Check length to avoid compiler warning alpha: Silence -Warray-bounds warnings m68k: cmpxchg: Dereference matching size intel_th: msu: Use memset_startat() for clearing hw header KVM: x86: Replace memset() "optimization" with normal per-field writes
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kvm/emulate.c9
-rw-r--r--arch/x86/kvm/kvm_emulate.h6
2 files changed, 8 insertions, 7 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index e86d610dc6b7..d8c087f1b831 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -5395,8 +5395,13 @@ static int fastop(struct x86_emulate_ctxt *ctxt, fastop_t fop)
void init_decode_cache(struct x86_emulate_ctxt *ctxt)
{
- memset(&ctxt->rip_relative, 0,
- (void *)&ctxt->modrm - (void *)&ctxt->rip_relative);
+ /* Clear fields that are set conditionally but read without a guard. */
+ ctxt->rip_relative = false;
+ ctxt->rex_prefix = 0;
+ ctxt->lock_prefix = 0;
+ ctxt->rep_prefix = 0;
+ ctxt->regs_valid = 0;
+ ctxt->regs_dirty = 0;
ctxt->io_read.pos = 0;
ctxt->io_read.end = 0;
diff --git a/arch/x86/kvm/kvm_emulate.h b/arch/x86/kvm/kvm_emulate.h
index 39eded2426ff..840ddb4a9302 100644
--- a/arch/x86/kvm/kvm_emulate.h
+++ b/arch/x86/kvm/kvm_emulate.h
@@ -336,11 +336,7 @@ struct x86_emulate_ctxt {
fastop_t fop;
};
int (*check_perm)(struct x86_emulate_ctxt *ctxt);
- /*
- * The following six fields are cleared together,
- * the rest are initialized unconditionally in x86_decode_insn
- * or elsewhere
- */
+
bool rip_relative;
u8 rex_prefix;
u8 lock_prefix;