Messages in this thread Patch in this message | | | From | Ameer Hamza <> | Subject | [PATCH v2] net: stmmac: Fix possible division by zero | Date | Mon, 6 Dec 2021 19:23:37 +0500 |
| |
In stmmac_init_tstamp_counter() routine, there is a possiblity of division by zero. If priv->plat->clk_ptp_rate becomes greater than 1 GHz, config_sub_second_increment() subroutine may calculate sec_inc as zero depending upon the PTP_TCR_TSCFUPDT register value, which will cause divide by zero exception.
Fixes: a6da2bbb0005e ("net: stmmac: retain PTP clock time during SIOCSHWTSTAMP ioctls") Addresses-Coverity: 1494557 ("Division or modulo by zero") Signed-off-by: Ameer Hamza <amhamza.mgc@gmail.com>
--- Changes in v2: Added fix tag, bug justification, and commit author. --- drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index da8306f60730..f44400323407 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -863,7 +863,7 @@ int stmmac_init_tstamp_counter(struct stmmac_priv *priv, u32 systime_flags) stmmac_config_sub_second_increment(priv, priv->ptpaddr, priv->plat->clk_ptp_rate, xmac, &sec_inc); - temp = div_u64(1000000000ULL, sec_inc); + temp = div_u64(1000000000ULL, (sec_inc > 0) ? sec_inc : 1); /* Store sub second increment for later use */ priv->sub_second_inc = sec_inc; -- 2.25.1
| |