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authorMasami Hiramatsu <mhiramat@kernel.org>2019-05-07 22:56:02 +0900
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-05-25 18:22:12 +0200
commitdda71c1663c808c72cb95d59cbd0989f767bd9d4 (patch)
treec4665ee3509cfb35b40f96c6b750b8e23451c2a8
parent95142e28042b1f51cbeec81488799d163eb67242 (diff)
tracing: probeevent: Fix to make the type of $comm string
commit 3dd1f7f24f8ceec00bbbc364c2ac3c893f0fdc4c upstream. Fix to make the type of $comm "string". If we set the other type to $comm argument, it shows meaningless value or wrong data. Currently probe events allow us to set string array type (e.g. ":string[2]"), or other digit types like x8 on $comm. But since clearly $comm is just a string data, it should not be fetched by other types including array. Link: http://lkml.kernel.org/r/155723736241.9149.14582064184468574539.stgit@devnote2 Cc: Andreas Ziegler <andreas.ziegler@fau.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: stable@vger.kernel.org Fixes: 533059281ee5 ("tracing: probeevent: Introduce new argument fetching code") Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--kernel/trace/trace_probe.c13
1 files changed, 7 insertions, 6 deletions
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index 9962cb5da8ac..44f078cda0ac 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -405,13 +405,14 @@ static int traceprobe_parse_probe_arg_body(char *arg, ssize_t *size,
return -E2BIG;
}
}
- /*
- * The default type of $comm should be "string", and it can't be
- * dereferenced.
- */
- if (!t && strcmp(arg, "$comm") == 0)
+
+ /* Since $comm can not be dereferred, we can find $comm by strcmp */
+ if (strcmp(arg, "$comm") == 0) {
+ /* The type of $comm must be "string", and not an array. */
+ if (parg->count || (t && strcmp(t, "string")))
+ return -EINVAL;
parg->type = find_fetch_type("string");
- else
+ } else
parg->type = find_fetch_type(t);
if (!parg->type) {
pr_info("Unsupported type: %s\n", t);