ARM: omap2+: fixing wrong strcat for Non-NULL terminated string
authorManinder Singh <maninder1.s@samsung.com>
Thu, 8 Dec 2016 04:10:30 +0000 (09:40 +0530)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Mon, 7 Aug 2017 01:59:44 +0000 (18:59 -0700)
[ Upstream commit 5066d5296ff2db20625e5f46e7338872c90c649f ]

Issue caught with static analysis tool:
"Dangerous usage of 'name' (strncpy doesn't always 0-terminate it)"

Use strlcpy _includes_ the NUL terminator, and  strlcat() which ensures
that it won't overflow the buffer.

Reported-by: Maninder Singh <maninder1.s@samsung.com>
Signed-off-by: Vaneet Narang <v.narang@samsung.com>
CC: Russell King <linux@armlinux.org.uk>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arch/arm/mach-omap2/omap_hwmod.c

index 1052b29..b5c1714 100644 (file)
@@ -790,14 +790,14 @@ static int _init_main_clk(struct omap_hwmod *oh)
        int ret = 0;
        char name[MOD_CLK_MAX_NAME_LEN];
        struct clk *clk;
+       static const char modck[] = "_mod_ck";
 
-       /* +7 magic comes from '_mod_ck' suffix */
-       if (strlen(oh->name) + 7 > MOD_CLK_MAX_NAME_LEN)
+       if (strlen(oh->name) >= MOD_CLK_MAX_NAME_LEN - strlen(modck))
                pr_warn("%s: warning: cropping name for %s\n", __func__,
                        oh->name);
 
-       strncpy(name, oh->name, MOD_CLK_MAX_NAME_LEN - 7);
-       strcat(name, "_mod_ck");
+       strlcpy(name, oh->name, MOD_CLK_MAX_NAME_LEN - strlen(modck));
+       strlcat(name, modck, MOD_CLK_MAX_NAME_LEN);
 
        clk = clk_get(NULL, name);
        if (!IS_ERR(clk)) {