2020-04-02 16:34:07

by Colin King

Subject: [PATCH][next] mlxsw: spectrum_trap: fix unintention integer overflow on left shift

From: Colin Ian King <[email protected]>

Shifting the integer value 1 is evaluated using 32-bit
arithmetic and then used in an expression that expects a 64-bit
value, so there is potentially an integer overflow. Fix this
by using the BIT_ULL macro to perform the shift and avoid the
overflow.

Addresses-Coverity: ("Unintentional integer overflow")
Fixes: 13f2e64b94ea ("mlxsw: spectrum_trap: Add devlink-trap policer support")
Signed-off-by: Colin Ian King <[email protected]>
---
drivers/net/ethernet/mellanox/mlxsw/spectrum_trap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_trap.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_trap.c
index 9096ffd89e50..fbf714d027d8 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_trap.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_trap.c
@@ -643,7 +643,7 @@ static int mlxsw_sp_trap_policer_bs(u64 burst, u8 *p_burst_size,
{
int bs = fls64(burst) - 1;

- if (burst != (1 << bs)) {
+ if (burst != (BIT_ULL(bs))) {
NL_SET_ERR_MSG_MOD(extack, "Policer burst size is not power of two");
return -EINVAL;
}
--
2.25.1

2020-04-02 16:48:40

by Ido Schimmel

Subject: Re: [PATCH][next] mlxsw: spectrum_trap: fix unintention integer overflow on left shift

On Thu, Apr 02, 2020 at 03:48:51PM +0100, Colin King wrote:
> From: Colin Ian King <[email protected]>
>
> Shifting the integer value 1 is evaluated using 32-bit
> arithmetic and then used in an expression that expects a 64-bit
> value, so there is potentially an integer overflow. Fix this
> by using the BIT_ULL macro to perform the shift and avoid the
> overflow.
>
> Addresses-Coverity: ("Unintentional integer overflow")
> Fixes: 13f2e64b94ea ("mlxsw: spectrum_trap: Add devlink-trap policer support")
> Signed-off-by: Colin Ian King <[email protected]>

For net:

Reviewed-by: Ido Schimmel <[email protected]>
Tested-by: Ido Schimmel <[email protected]>

Thanks

2020-04-03 01:02:29

by David Miller

Subject: Re: [PATCH][next] mlxsw: spectrum_trap: fix unintention integer overflow on left shift

From: Colin King <[email protected]>
Date: Thu, 2 Apr 2020 15:48:51 +0100

> From: Colin Ian King <[email protected]>
>
> Shifting the integer value 1 is evaluated using 32-bit
> arithmetic and then used in an expression that expects a 64-bit
> value, so there is potentially an integer overflow. Fix this
> by using the BIT_ULL macro to perform the shift and avoid the
> overflow.
>
> Addresses-Coverity: ("Unintentional integer overflow")
> Fixes: 13f2e64b94ea ("mlxsw: spectrum_trap: Add devlink-trap policer support")
> Signed-off-by: Colin Ian King <[email protected]>

Applied, thanks.

2020-04-03 08:47:47

by Dan Carpenter

Subject: Re: [PATCH][next] mlxsw: spectrum_trap: fix unintention integer overflow on left shift

On Thu, Apr 02, 2020 at 03:48:51PM +0100, Colin King wrote:
> From: Colin Ian King <[email protected]>
>
> Shifting the integer value 1 is evaluated using 32-bit
> arithmetic and then used in an expression that expects a 64-bit
> value, so there is potentially an integer overflow. Fix this
> by using the BIT_ULL macro to perform the shift and avoid the
> overflow.
>
> Addresses-Coverity: ("Unintentional integer overflow")
> Fixes: 13f2e64b94ea ("mlxsw: spectrum_trap: Add devlink-trap policer support")
> Signed-off-by: Colin Ian King <[email protected]>
> ---
> drivers/net/ethernet/mellanox/mlxsw/spectrum_trap.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_trap.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_trap.c
> index 9096ffd89e50..fbf714d027d8 100644
> --- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_trap.c
> +++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_trap.c
> @@ -643,7 +643,7 @@ static int mlxsw_sp_trap_policer_bs(u64 burst, u8 *p_burst_size,
> {
> int bs = fls64(burst) - 1;
>
> - if (burst != (1 << bs)) {
> + if (burst != (BIT_ULL(bs))) {

Please delete the extra parentheses.

if (burst != BIT_ULL(bs)) {

regards,
dan carpenter