The "sym" calculation is actually a fixed size, but since the max() macro uses some extensive tricks for safety, it ends up looking like a variable size. This replaces max() with a simple max macro which is sufficient for the calculation of the array size.
Seen with -Wvla. Fixed as part of the directive to remove all VLAs from the kernel: https://lkml.org/lkml/2018/3/7/621 Signed-off-by: Kees Cook <keesc...@chromium.org> --- lib/vsprintf.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/lib/vsprintf.c b/lib/vsprintf.c index d7a708f82559..f420ab1477cb 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -744,8 +744,9 @@ char *resource_string(char *buf, char *end, struct resource *res, #define FLAG_BUF_SIZE (2 * sizeof(res->flags)) #define DECODED_BUF_SIZE sizeof("[mem - 64bit pref window disabled]") #define RAW_BUF_SIZE sizeof("[mem - flags 0x]") - char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE, - 2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)]; +#define SIMPLE_MAX(x, y) ((x) > (y) ? (x) : (y)) + char sym[SIMPLE_MAX(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE, + 2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)]; char *p = sym, *pend = sym + sizeof(sym); int decode = (fmt[0] == 'R') ? 1 : 0; -- 2.7.4 -- Kees Cook Pixel Security
