[PATCH] kprobes/x86: opt: free optinsn cache when range check fails

From: Wang Nan
Date: Mon Jul 28 2014 - 08:30:52 EST


This patch frees optinsn slot when range check error to prevent memory
leaks. Before this patch, cache entry in kprobe_insn_cache won't be
freed if kprobe optimizing fails due to range check failure.

Signed-off-by: Wang Nan <wangnan0@xxxxxxxxxx>
---
arch/x86/kernel/kprobes/opt.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c
index f304773..f1314d0 100644
--- a/arch/x86/kernel/kprobes/opt.c
+++ b/arch/x86/kernel/kprobes/opt.c
@@ -338,8 +338,10 @@ int arch_prepare_optimized_kprobe(struct optimized_kprobe *op)
* a relative jump.
*/
rel = (long)op->optinsn.insn - (long)op->kp.addr + RELATIVEJUMP_SIZE;
- if (abs(rel) > 0x7fffffff)
+ if (abs(rel) > 0x7fffffff) {
+ __arch_remove_optimized_kprobe(op, 0);
return -ERANGE;
+ }

buf = (u8 *)op->optinsn.insn;

--
1.8.4

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