From 10b8eb94c0902b58d83df84a9eeae709a3480e82 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Wed, 24 Mar 2021 10:46:50 -0600 Subject: [PATCH] target/i386: Verify memory operand for lcall and ljmp These two opcodes only allow a memory operand. Lacking the check for a register operand, we used the A0 temp without initialization, which led to a tcg abort. Buglink: https://bugs.launchpad.net/qemu/+bug/1921138 Signed-off-by: Richard Henderson Message-Id: <20210324164650.128608-1-richard.henderson@linaro.org> Signed-off-by: Paolo Bonzini --- target/i386/tcg/translate.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/target/i386/tcg/translate.c b/target/i386/tcg/translate.c index af1faf9342..880bc45561 100644 --- a/target/i386/tcg/translate.c +++ b/target/i386/tcg/translate.c @@ -5061,6 +5061,9 @@ static target_ulong disas_insn(DisasContext *s, CPUState *cpu) gen_jr(s, s->T0); break; case 3: /* lcall Ev */ + if (mod == 3) { + goto illegal_op; + } gen_op_ld_v(s, ot, s->T1, s->A0); gen_add_A0_im(s, 1 << ot); gen_op_ld_v(s, MO_16, s->T0, s->A0); @@ -5088,6 +5091,9 @@ static target_ulong disas_insn(DisasContext *s, CPUState *cpu) gen_jr(s, s->T0); break; case 5: /* ljmp Ev */ + if (mod == 3) { + goto illegal_op; + } gen_op_ld_v(s, ot, s->T1, s->A0); gen_add_A0_im(s, 1 << ot); gen_op_ld_v(s, MO_16, s->T0, s->A0);