diff options
| author | Wu Xiang <willx8@gmail.com> | 2017-06-21 22:21:56 +0800 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2017-07-04 14:30:03 +0200 |
| commit | e95e9b88ba5f4a6c17f4d0c3a3a6bf3f648bb328 (patch) | |
| tree | 75c85c71f91ab69549f38273c72f531ee728fe96 /target | |
| parent | 96d06835dc40007673cdfab6322e9042c4077113 (diff) | |
target/i386: fix interrupt CPL error when using ist in x86-64
In do_interrupt64(), when interrupt stack table(ist) is enabled
and the the target code segment is conforming(e2 & DESC_C_MASK), the
old implementation always set new CPL to 0, and SS.RPL to 0.
This is incorrect for when CPL3 code access a CPL0 conforming code
segment, the CPL should remain unchanged. Otherwise higher privileged
code can be compromised.
The patch fix this for always set dpl = cpl when the target code segment
is conforming, and modify the last parameter `flags`, which contains
correct new CPL, in cpu_x86_load_seg_cache().
Signed-off-by: Wu Xiang <willx8@gmail.com>
Message-Id: <20170621142152.GA18094@wxdeubuntu.ipads-lab.se.sjtu.edu.cn>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'target')
| -rw-r--r-- | target/i386/seg_helper.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/target/i386/seg_helper.c b/target/i386/seg_helper.c index 0374031ea2..9af69c23e0 100644 --- a/target/i386/seg_helper.c +++ b/target/i386/seg_helper.c @@ -931,12 +931,14 @@ static void do_interrupt64(CPUX86State *env, int intno, int is_int, } new_stack = 0; esp = env->regs[R_ESP]; - dpl = cpl; } else { raise_exception_err(env, EXCP0D_GPF, selector & 0xfffc); new_stack = 0; /* avoid warning */ esp = 0; /* avoid warning */ } + if (e2 & DESC_C_MASK) { + dpl = cpl; + } esp &= ~0xfLL; /* align stack */ PUSHQ(esp, env->segs[R_SS].selector); @@ -956,7 +958,7 @@ static void do_interrupt64(CPUX86State *env, int intno, int is_int, if (new_stack) { ss = 0 | dpl; - cpu_x86_load_seg_cache(env, R_SS, ss, 0, 0, 0); + cpu_x86_load_seg_cache(env, R_SS, ss, 0, 0, dpl << DESC_DPL_SHIFT); } env->regs[R_ESP] = esp; |