[PATCH v2] net: stmmac: Fix possible division by zero
flat view
STALE1778d
From: Ameer Hamza <hidden>
Date: 2021-12-06 14:24:11
Also in:
lkml
Subsystem:
networking drivers, stmmac ethernet driver, the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Maxime Chevallier, Linus Torvalds
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 <redacted>
---
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