2023-04-06 10:03:22

by Radu Pirea (NXP OSS)

Subject: [PATCH net] net: phy: nxp-c45-tja11xx: fix unsigned long multiplication overflow

Any multiplication between GENMASK(31, 0) and a number bigger than 1
will be truncated because of the overflow, if the size of unsigned long
is 32 bits.

Replaced GENMASK with GENMASK_ULL to make sure that multiplication will
be between 64 bits values.

Cc: <[email protected]> # 5.15+
Fixes: 514def5dd339 ("phy: nxp-c45-tja11xx: add timestamping support")
Signed-off-by: Radu Pirea (OSS) <[email protected]>
---
drivers/net/phy/nxp-c45-tja11xx.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/phy/nxp-c45-tja11xx.c b/drivers/net/phy/nxp-c45-tja11xx.c
index 27738d1ae9ea..029875a59ff8 100644
--- a/drivers/net/phy/nxp-c45-tja11xx.c
+++ b/drivers/net/phy/nxp-c45-tja11xx.c
@@ -191,7 +191,7 @@
#define MAX_ID_PS 2260U
#define DEFAULT_ID_PS 2000U

-#define PPM_TO_SUBNS_INC(ppb) div_u64(GENMASK(31, 0) * (ppb) * \
+#define PPM_TO_SUBNS_INC(ppb) div_u64(GENMASK_ULL(31, 0) * (ppb) * \
PTP_CLK_PERIOD_100BT1, NSEC_PER_SEC)

#define NXP_C45_SKB_CB(skb) ((struct nxp_c45_skb_cb *)(skb)->cb)
--
2.34.1

2023-04-07 14:24:55

by Andrew Lunn

Subject: Re: [PATCH net] net: phy: nxp-c45-tja11xx: fix unsigned long multiplication overflow

On Thu, Apr 06, 2023 at 12:59:53PM +0300, Radu Pirea (OSS) wrote:
> Any multiplication between GENMASK(31, 0) and a number bigger than 1
> will be truncated because of the overflow, if the size of unsigned long
> is 32 bits.
>
> Replaced GENMASK with GENMASK_ULL to make sure that multiplication will
> be between 64 bits values.
>
> Cc: <[email protected]> # 5.15+
> Fixes: 514def5dd339 ("phy: nxp-c45-tja11xx: add timestamping support")
> Signed-off-by: Radu Pirea (OSS) <[email protected]>

Reviewed-by: Andrew Lunn <[email protected]>

Andrew

2023-04-08 02:52:25

by patchwork-bot+netdevbpf

Subject: Re: [PATCH net] net: phy: nxp-c45-tja11xx: fix unsigned long multiplication overflow

Hello:

This patch was applied to netdev/net.git (main)
by Jakub Kicinski <[email protected]>:

On Thu, 6 Apr 2023 12:59:53 +0300 you wrote:
> Any multiplication between GENMASK(31, 0) and a number bigger than 1
> will be truncated because of the overflow, if the size of unsigned long
> is 32 bits.
>
> Replaced GENMASK with GENMASK_ULL to make sure that multiplication will
> be between 64 bits values.
>
> [...]

Here is the summary with links:
- [net] net: phy: nxp-c45-tja11xx: fix unsigned long multiplication overflow
https://git.kernel.org/netdev/net/c/bdaaecc127d4

You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html