Messages in this thread Patch in this message | | | Date | Tue, 26 Jan 2010 15:34:52 -0800 | From | Greg KH <> | Subject | [86/98] KVM: S390: fix potential array overrun in intercept handling |
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2.6.32-stable review patch. If anyone has any objections, please let us know.
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From: Christian Borntraeger <borntraeger@de.ibm.com>
commit 062d5e9b0d714f449b261bb522eadaaf6f00f438 upstream.
kvm_handle_sie_intercept uses a jump table to get the intercept handler for a SIE intercept. Static code analysis revealed a potential problem: the intercept_funcs jump table was defined to contain (0x48 >> 2) entries, but we only checked for code > 0x48 which would cause an off-by-one array overflow if code == 0x48.
Use the compiler and ARRAY_SIZE to automatically set the limits.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- arch/s390/kvm/intercept.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/arch/s390/kvm/intercept.c +++ b/arch/s390/kvm/intercept.c @@ -213,7 +213,7 @@ static int handle_instruction_and_prog(s return rc2; } -static const intercept_handler_t intercept_funcs[0x48 >> 2] = { +static const intercept_handler_t intercept_funcs[] = { [0x00 >> 2] = handle_noop, [0x04 >> 2] = handle_instruction, [0x08 >> 2] = handle_prog, @@ -230,7 +230,7 @@ int kvm_handle_sie_intercept(struct kvm_ intercept_handler_t func; u8 code = vcpu->arch.sie_block->icptcode; - if (code & 3 || code > 0x48) + if (code & 3 || (code >> 2) >= ARRAY_SIZE(intercept_funcs)) return -ENOTSUPP; func = intercept_funcs[code >> 2]; if (func)
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