From: Colin Ian King Date: Fri, 1 May 2020 14:10:16 +0000 (+0100) Subject: net: stmmac: gmac5+: fix potential integer overflow on 32 bit multiply X-Git-Tag: v5.15~3931^2~22 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=44d95cc6b10ff7439d45839c96c581cb4368c088;p=platform%2Fkernel%2Flinux-starfive.git net: stmmac: gmac5+: fix potential integer overflow on 32 bit multiply The multiplication of cfg->ctr[1] by 1000000000 is performed using a 32 bit multiplication (since cfg->ctr[1] is a u32) and this can lead to a potential overflow. Fix this by making the constant a ULL to ensure a 64 bit multiply occurs. Fixes: 504723af0d85 ("net: stmmac: Add basic EST support for GMAC5+") Addresses-Coverity: ("Unintentional integer overflow") Signed-off-by: Colin Ian King Signed-off-by: David S. Miller --- diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac5.c b/drivers/net/ethernet/stmicro/stmmac/dwmac5.c index 494c859..67ba67e 100644 --- a/drivers/net/ethernet/stmicro/stmmac/dwmac5.c +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac5.c @@ -624,7 +624,7 @@ int dwmac5_est_configure(void __iomem *ioaddr, struct stmmac_est *cfg, total_offset += offset; } - total_ctr = cfg->ctr[0] + cfg->ctr[1] * 1000000000; + total_ctr = cfg->ctr[0] + cfg->ctr[1] * 1000000000ULL; total_ctr += total_offset; ctr_low = do_div(total_ctr, 1000000000);