[PATCH v2] arch/x86/kernel: check the return value of insn_decode_kernel()

From: Li Zhong
Date: Wed Sep 07 2022 - 04:54:54 EST


insn_decode() could fail and the insn.length could be invalid. So we
need to check the return value first.

Signed-off-by: Li Zhong <floridsleeves@xxxxxxxxx>
---
arch/x86/kernel/jump_label.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/jump_label.c b/arch/x86/kernel/jump_label.c
index f5b8ef02d172..59385700f579 100644
--- a/arch/x86/kernel/jump_label.c
+++ b/arch/x86/kernel/jump_label.c
@@ -20,9 +20,10 @@
int arch_jump_entry_size(struct jump_entry *entry)
{
struct insn insn = {};
+ int ret;

- insn_decode_kernel(&insn, (void *)jump_entry_code(entry));
- BUG_ON(insn.length != 2 && insn.length != 5);
+ ret = insn_decode_kernel(&insn, (void *)jump_entry_code(entry));
+ BUG_ON(ret < 0 || (insn.length != 2 && insn.length != 5));

return insn.length;
}
--
2.25.1