| Message ID | 1480589913-8839-1-git-send-email-maninder1.s@samsung.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Dec 01, 2016 at 04:28:33PM +0530, Maninder Singh wrote: > variable name can have Non NULL terminated string after cropping > which may result strcat to fail, and cropping is not > required if (strlen(oh->name) + 8 < MOD_CLK_MAX_NAME_LEN). > > Issue caught with static analysis tool: > "Dangerous usage of 'name' (strncpy doesn't always 0-terminate it)" > > Signed-off-by: Vaneet Narang <v.narang@samsung.com> > Signed-off-by: Maninder Singh <maninder1.s@samsung.com> > --- > v1 -> v2: changed strncpy to strlcpy > arch/arm/mach-omap2/omap_hwmod.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c > index 759e1d4..582b95a 100644 > --- a/arch/arm/mach-omap2/omap_hwmod.c > +++ b/arch/arm/mach-omap2/omap_hwmod.c > @@ -742,12 +742,14 @@ static int _init_main_clk(struct omap_hwmod *oh) > char name[MOD_CLK_MAX_NAME_LEN]; > struct clk *clk; > > - /* +7 magic comes from '_mod_ck' suffix */ > - if (strlen(oh->name) + 7 > MOD_CLK_MAX_NAME_LEN) > + /* +8 magic comes from strlen("_mod_ck") added as suffix */ > + if (strlen(oh->name) + 8 > MOD_CLK_MAX_NAME_LEN) { > pr_warn("%s: warning: cropping name for %s\n", __func__, > oh->name); > + strlcpy(name, oh->name, MOD_CLK_MAX_NAME_LEN - 7); > + } else > + strcpy(name, oh->name); > > - strncpy(name, oh->name, MOD_CLK_MAX_NAME_LEN - 7); > strcat(name, "_mod_ck"); > > clk = clk_get(NULL, name); > -- > 1.9.1 > Simpler, clearer, and less error-prone: static const char modck[] = "_mod_ck"; if (strlen(oh->name) >= MOD_CLK_MAX_NAME_LEN - strlen(modck)) pr_warn("%s: warning: cropping name for %s\n", __func__, oh->name); strlcpy(name, oh->name, MOD_CLK_MAX_NAME_LEN - strlen(modck)); strlcat(name, modck, MOD_CLK_MAX_NAME_LEN); Note that the length argument to strlcpy _includes_ the NUL terminator. Also note the use of strlcat() which ensures that it won't overflow the buffer.
diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c index 759e1d4..582b95a 100644 --- a/arch/arm/mach-omap2/omap_hwmod.c +++ b/arch/arm/mach-omap2/omap_hwmod.c @@ -742,12 +742,14 @@ static int _init_main_clk(struct omap_hwmod *oh) char name[MOD_CLK_MAX_NAME_LEN]; struct clk *clk; - /* +7 magic comes from '_mod_ck' suffix */ - if (strlen(oh->name) + 7 > MOD_CLK_MAX_NAME_LEN) + /* +8 magic comes from strlen("_mod_ck") added as suffix */ + if (strlen(oh->name) + 8 > MOD_CLK_MAX_NAME_LEN) { pr_warn("%s: warning: cropping name for %s\n", __func__, oh->name); + strlcpy(name, oh->name, MOD_CLK_MAX_NAME_LEN - 7); + } else + strcpy(name, oh->name); - strncpy(name, oh->name, MOD_CLK_MAX_NAME_LEN - 7); strcat(name, "_mod_ck"); clk = clk_get(NULL, name);