tracing/probes: check the return value of kstrndup() for pbuf

BugLink: https://bugs.launchpad.net/bugs/1964361
[ Upstream commit 1c1857d400355e96f0fe8b32adc6fa7594d03b52 ]

kstrndup() is a memory allocation-related function, it returns NULL when
some internal memory errors happen. It is better to check the return
value of it so to catch the memory error in time.

Link: https://lkml.kernel.org/r/tencent_4D6E270731456EB88712ED7F13883C334906@qq.com
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: a42e3c4de964 ("tracing/probe: Add immediate string parameter support")
Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>

diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index 3ed2a3f372972cd3fe9e83fb142c1a608a57be9f..bb4605b60de799b17ae4dba7c5b6ce5f0f40be06 100644 (file)
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -356,6 +356,8 @@ static int __parse_imm_string(char *str, char **pbuf, int offs)
                return -EINVAL;
        }
        *pbuf = kstrndup(str, len - 1, GFP_KERNEL);
+       if (!*pbuf)
+               return -ENOMEM;
        return 0;
 }