From: Dan Carpenter Date: Wed, 28 May 2025 08:11:09 +0000 (+0300) Subject: net/mlx4_en: Prevent potential integer overflow calculating Hz X-Git-Tag: v6.16-rc1~36^2~33 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=54d34165b4f786d7fea8412a18fb4a54c1eab623;p=thirdparty%2Flinux.git net/mlx4_en: Prevent potential integer overflow calculating Hz The "freq" variable is in terms of MHz and "max_val_cycles" is in terms of Hz. The fact that "max_val_cycles" is a u64 suggests that support for high frequency is intended but the "freq_khz * 1000" would overflow the u32 type if we went above 4GHz. Use unsigned long long type for the mutliplication to prevent that. Fixes: 31c128b66e5b ("net/mlx4_en: Choose time-stamping shift value according to HW frequency") Signed-off-by: Dan Carpenter Reviewed-by: Simon Horman Link: https://patch.msgid.link/aDbFHe19juIJKjsb@stanley.mountain Signed-off-by: Paolo Abeni --- diff --git a/drivers/net/ethernet/mellanox/mlx4/en_clock.c b/drivers/net/ethernet/mellanox/mlx4/en_clock.c index cd754cd76bde..d73a2044dc26 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_clock.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_clock.c @@ -249,7 +249,7 @@ static const struct ptp_clock_info mlx4_en_ptp_clock_info = { static u32 freq_to_shift(u16 freq) { u32 freq_khz = freq * 1000; - u64 max_val_cycles = freq_khz * 1000 * MLX4_EN_WRAP_AROUND_SEC; + u64 max_val_cycles = freq_khz * 1000ULL * MLX4_EN_WRAP_AROUND_SEC; u64 max_val_cycles_rounded = 1ULL << fls64(max_val_cycles - 1); /* calculate max possible multiplier in order to fit in 64bit */ u64 max_mul = div64_u64(ULLONG_MAX, max_val_cycles_rounded);