From 3577afb0052fca65e67efdfc8e0859bb7bac87a6 Mon Sep 17 00:00:00 2001 From: Jim Cromie Date: Wed, 9 Dec 2020 11:36:25 -0700 Subject: dyndbg: fix use before null check In commit a2d375eda771 ("dyndbg: refine export, rename to dynamic_debug_exec_queries()"), a string is copied before checking it isn't NULL. Fix this, report a usage/interface error, and return the proper error code. Fixes: a2d375eda771 ("dyndbg: refine export, rename to dynamic_debug_exec_queries()") Cc: stable@vger.kernel.org -- -v2 drop comment tweak, improve commit message Signed-off-by: Jim Cromie Link: https://lore.kernel.org/r/20201209183625.2432329-1-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman --- lib/dynamic_debug.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'lib') diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index bd7b3aaa93c3..c70d6347afa2 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -561,9 +561,14 @@ static int ddebug_exec_queries(char *query, const char *modname) int dynamic_debug_exec_queries(const char *query, const char *modname) { int rc; - char *qry = kstrndup(query, PAGE_SIZE, GFP_KERNEL); + char *qry; /* writable copy of query */ - if (!query) + if (!query) { + pr_err("non-null query/command string expected\n"); + return -EINVAL; + } + qry = kstrndup(query, PAGE_SIZE, GFP_KERNEL); + if (!qry) return -ENOMEM; rc = ddebug_exec_queries(qry, modname); -- cgit v1.2.3