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| author |   Joerg Roedel <jroedel@suse.de> | 2021-06-14 15:53:27 +0200 |
|---|---|---|
| committer |   Borislav Petkov <bp@suse.de> | 2021-06-15 11:55:26 +0200 |
| commit | 07570cef5e5c3fcec40f82a9075abb4c1da63319 (patch) | |
| tree | 528d5b55c635943ac7129bb6329376be07310d67 /arch/x86/kernel/sev.c | |
| parent | x86/insn: Extend error reporting from insn_fetch_from_user[_inatomic]() (diff) | |
| download | linux-dev-07570cef5e5c3fcec40f82a9075abb4c1da63319.tar.xz linux-dev-07570cef5e5c3fcec40f82a9075abb4c1da63319.zip | |
x86/sev: Propagate #GP if getting linear instruction address failed
When an instruction is fetched from user-space, segmentation needs to
be taken into account. This means that getting the linear address of an
instruction can fail. Hardware would raise a #GP exception in that case,
but the #VC exception handler would emulate it as a page-fault.
The insn_fetch_from_user*() functions now provide the relevant
information in case of a failure. Use that and propagate a #GP when the
linear address of an instruction to fetch could not be calculated.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210614135327.9921-7-joro@8bytes.org
Diffstat (limited to 'arch/x86/kernel/sev.c')
| -rw-r--r-- | arch/x86/kernel/sev.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c index a1eeaa79bf2b..8178db07a06a 100644 --- a/arch/x86/kernel/sev.c +++ b/arch/x86/kernel/sev.c @@ -261,11 +261,18 @@ static enum es_result __vc_decode_user_insn(struct es_em_ctxt *ctxt) int insn_bytes; insn_bytes = insn_fetch_from_user_inatomic(ctxt->regs, buffer); - if (insn_bytes <= 0) { + if (insn_bytes == 0) { + /* Nothing could be copied */ ctxt->fi.vector = X86_TRAP_PF; ctxt->fi.error_code = X86_PF_INSTR | X86_PF_USER; ctxt->fi.cr2 = ctxt->regs->ip; return ES_EXCEPTION; + } else if (insn_bytes == -EINVAL) { + /* Effective RIP could not be calculated */ + ctxt->fi.vector = X86_TRAP_GP; + ctxt->fi.error_code = 0; + ctxt->fi.cr2 = 0; + return ES_EXCEPTION; } if (!insn_decode_from_regs(&ctxt->insn, ctxt->regs, buffer, insn_bytes)) |