From: Borislav Petkov <bp@alien8.de>
To: Andy Lutomirski <luto@amacapital.net>,
Masami Hiramatsu <mhiramat@kernel.org>
Cc: X86 ML <x86@kernel.org>, LKML <linux-kernel@vger.kernel.org>
Subject: [PATCH v1 04/19] x86/insn-eval: Handle return values from the decoder
Date: Wed, 23 Dec 2020 18:42:18 +0100 [thread overview]
Message-ID: <20201223174233.28638-5-bp@alien8.de> (raw)
In-Reply-To: <20201223174233.28638-1-bp@alien8.de>
From: Borislav Petkov <bp@suse.de>
Now that the different instruction-inspecting functions return a value,
test that and return early from callers if error has been encountered.
While at it, do not call insn_get_modrm() when calling
insn_get_displacement() because latter will make sure to call
insn_get_modrm() if ModRM hasn't been parsed yet.
Signed-off-by: Borislav Petkov <bp@suse.de>
---
arch/x86/lib/insn-eval.c | 19 +++++++++++++------
1 file changed, 13 insertions(+), 6 deletions(-)
diff --git a/arch/x86/lib/insn-eval.c b/arch/x86/lib/insn-eval.c
index 265d23a0c334..7e49aaf5454c 100644
--- a/arch/x86/lib/insn-eval.c
+++ b/arch/x86/lib/insn-eval.c
@@ -1106,18 +1106,21 @@ static int get_eff_addr_modrm_16(struct insn *insn, struct pt_regs *regs,
* @base_offset will have a register, as an offset from the base of pt_regs,
* that can be used to resolve the associated segment.
*
- * -EINVAL on error.
+ * Negative value on error.
*/
static int get_eff_addr_sib(struct insn *insn, struct pt_regs *regs,
int *base_offset, long *eff_addr)
{
long base, indx;
int indx_offset;
+ int ret;
if (insn->addr_bytes != 8 && insn->addr_bytes != 4)
return -EINVAL;
- insn_get_modrm(insn);
+ ret = insn_get_modrm(insn);
+ if (ret)
+ return ret;
if (!insn->modrm.nbytes)
return -EINVAL;
@@ -1125,7 +1128,9 @@ static int get_eff_addr_sib(struct insn *insn, struct pt_regs *regs,
if (X86_MODRM_MOD(insn->modrm.value) > 2)
return -EINVAL;
- insn_get_sib(insn);
+ ret = insn_get_sib(insn);
+ if (ret)
+ return ret;
if (!insn->sib.nbytes)
return -EINVAL;
@@ -1194,8 +1199,8 @@ static void __user *get_addr_ref_16(struct insn *insn, struct pt_regs *regs)
short eff_addr;
long tmp;
- insn_get_modrm(insn);
- insn_get_displacement(insn);
+ if (insn_get_displacement(insn))
+ goto out;
if (insn->addr_bytes != 2)
goto out;
@@ -1491,7 +1496,9 @@ bool insn_decode_regs(struct insn *insn, struct pt_regs *regs,
insn->addr_bytes = INSN_CODE_SEG_ADDR_SZ(seg_defs);
insn->opnd_bytes = INSN_CODE_SEG_OPND_SZ(seg_defs);
- insn_get_length(insn);
+ if (insn_get_length(insn))
+ return false;
+
if (buf_size < insn->length)
return false;
--
2.29.2
next prev parent reply other threads:[~2020-12-23 17:43 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-23 17:42 [PATCH v1 00/19] x86/insn: Add an insn_decode() API Borislav Petkov
2020-12-23 17:42 ` [PATCH v1 01/19] x86/insn: Rename insn_decode() to insn_decode_regs() Borislav Petkov
2020-12-28 17:16 ` Sean Christopherson
2020-12-29 19:36 ` Borislav Petkov
2020-12-23 17:42 ` [PATCH v1 02/19] x86/insn: Add @buf_len param to insn_init() kernel-doc comment Borislav Petkov
2020-12-28 1:44 ` Masami Hiramatsu
2020-12-23 17:42 ` [PATCH v1 03/19] x86/insn: Add an insn_decode() API Borislav Petkov
2020-12-28 1:15 ` Masami Hiramatsu
2020-12-29 20:06 ` Borislav Petkov
2020-12-30 9:00 ` Masami Hiramatsu
2020-12-30 9:28 ` Borislav Petkov
2021-01-06 5:21 ` Masami Hiramatsu
2021-01-08 18:59 ` Borislav Petkov
2021-01-12 11:34 ` Masami Hiramatsu
2021-01-13 18:06 ` Borislav Petkov
2020-12-23 17:42 ` Borislav Petkov [this message]
2020-12-28 18:51 ` [PATCH v1 04/19] x86/insn-eval: Handle return values from the decoder Sean Christopherson
2020-12-28 19:06 ` Borislav Petkov
2020-12-23 17:42 ` [PATCH v1 05/19] x86/boot/compressed/sev-es: Convert to insn_decode() Borislav Petkov
2020-12-23 17:42 ` [PATCH v1 06/19] perf/x86/intel/ds: Check insn_get_length() retval Borislav Petkov
2021-01-04 13:19 ` Peter Zijlstra
2021-01-19 10:40 ` Borislav Petkov
2020-12-23 17:42 ` [PATCH v1 07/19] perf/x86/intel/ds: Check return values of insn decoder functions Borislav Petkov
2020-12-23 17:42 ` [PATCH v1 08/19] x86/alternative: Use insn_decode() Borislav Petkov
2020-12-23 17:42 ` [PATCH v1 09/19] x86/mce: Convert to insn_decode() Borislav Petkov
2020-12-23 17:42 ` [PATCH v1 10/19] x86/kprobes: " Borislav Petkov
2020-12-23 17:42 ` [PATCH v1 11/19] x86/sev-es: " Borislav Petkov
2020-12-25 10:50 ` kernel test robot
2020-12-25 12:33 ` Borislav Petkov
2020-12-28 19:15 ` Sean Christopherson
2021-01-21 16:58 ` Borislav Petkov
2021-01-21 22:35 ` Sean Christopherson
2020-12-23 17:42 ` [PATCH v1 12/19] x86/traps: " Borislav Petkov
2020-12-23 17:42 ` [PATCH v1 13/19] x86/uprobes: " Borislav Petkov
2020-12-23 17:42 ` [PATCH v1 14/19] x86/tools/insn_decoder_test: " Borislav Petkov
2020-12-23 17:42 ` [PATCH v1 15/19] tools/objtool: " Borislav Petkov
2020-12-23 17:42 ` [PATCH v1 16/19] x86/tools/insn_sanity: " Borislav Petkov
2020-12-23 17:42 ` [PATCH v1 17/19] tools/perf: " Borislav Petkov
2020-12-23 17:42 ` [PATCH v1 18/19] x86/insn: Remove kernel_insn_init() Borislav Petkov
2020-12-23 17:42 ` [PATCH v1 19/19] x86/insn: Make insn_complete() static Borislav Petkov
2020-12-27 15:26 ` [PATCH v1 00/19] x86/insn: Add an insn_decode() API Tom Lendacky
2021-02-03 12:00 ` Borislav Petkov
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