2023-08-21 10:28:47

by GONG, Ruiqi

[permalink] [raw]
Subject: [PATCH RESEND net-next] alx: fix OOB-read compiler warning

From: "GONG, Ruiqi" <[email protected]>

The following message shows up when compiling with W=1:

In function ‘fortify_memcpy_chk’,
inlined from ‘alx_get_ethtool_stats’ at drivers/net/ethernet/atheros/alx/ethtool.c:297:2:
./include/linux/fortify-string.h:592:4: error: call to ‘__read_overflow2_field’
declared with attribute warning: detected read beyond size of field (2nd parameter);
maybe use struct_group()? [-Werror=attribute-warning]
592 | __read_overflow2_field(q_size_field, size);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

In order to get alx stats altogether, alx_get_ethtool_stats() reads
beyond hw->stats.rx_ok. Fix this warning by directly copying hw->stats,
and refactor the unnecessarily complicated BUILD_BUG_ON btw.

Signed-off-by: GONG, Ruiqi <[email protected]>
---

RESEND: forget to cc netdev mail list

drivers/net/ethernet/atheros/alx/ethtool.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/atheros/alx/ethtool.c b/drivers/net/ethernet/atheros/alx/ethtool.c
index b716adacd815..7f6b69a52367 100644
--- a/drivers/net/ethernet/atheros/alx/ethtool.c
+++ b/drivers/net/ethernet/atheros/alx/ethtool.c
@@ -292,9 +292,8 @@ static void alx_get_ethtool_stats(struct net_device *netdev,
spin_lock(&alx->stats_lock);

alx_update_hw_stats(hw);
- BUILD_BUG_ON(sizeof(hw->stats) - offsetof(struct alx_hw_stats, rx_ok) <
- ALX_NUM_STATS * sizeof(u64));
- memcpy(data, &hw->stats.rx_ok, ALX_NUM_STATS * sizeof(u64));
+ BUILD_BUG_ON(sizeof(hw->stats) != ALX_NUM_STATS * sizeof(u64));
+ memcpy(data, &hw->stats, sizeof(hw->stats));

spin_unlock(&alx->stats_lock);
}
--
2.25.1



2023-08-21 14:43:13

by Simon Horman

[permalink] [raw]
Subject: Re: [PATCH RESEND net-next] alx: fix OOB-read compiler warning

On Mon, Aug 21, 2023 at 09:32:18AM +0800, GONG, Ruiqi wrote:
> From: "GONG, Ruiqi" <[email protected]>
>
> The following message shows up when compiling with W=1:
>
> In function ‘fortify_memcpy_chk’,
> inlined from ‘alx_get_ethtool_stats’ at drivers/net/ethernet/atheros/alx/ethtool.c:297:2:
> ./include/linux/fortify-string.h:592:4: error: call to ‘__read_overflow2_field’
> declared with attribute warning: detected read beyond size of field (2nd parameter);
> maybe use struct_group()? [-Werror=attribute-warning]
> 592 | __read_overflow2_field(q_size_field, size);
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> In order to get alx stats altogether, alx_get_ethtool_stats() reads
> beyond hw->stats.rx_ok. Fix this warning by directly copying hw->stats,
> and refactor the unnecessarily complicated BUILD_BUG_ON btw.
>
> Signed-off-by: GONG, Ruiqi <[email protected]>

Reviewed-by: Simon Horman <[email protected]>


2023-08-22 12:33:30

by patchwork-bot+netdevbpf

[permalink] [raw]
Subject: Re: [PATCH RESEND net-next] alx: fix OOB-read compiler warning

Hello:

This patch was applied to netdev/net-next.git (main)
by Paolo Abeni <[email protected]>:

On Mon, 21 Aug 2023 09:32:18 +0800 you wrote:
> From: "GONG, Ruiqi" <[email protected]>
>
> The following message shows up when compiling with W=1:
>
> In function ‘fortify_memcpy_chk’,
> inlined from ‘alx_get_ethtool_stats’ at drivers/net/ethernet/atheros/alx/ethtool.c:297:2:
> ./include/linux/fortify-string.h:592:4: error: call to ‘__read_overflow2_field’
> declared with attribute warning: detected read beyond size of field (2nd parameter);
> maybe use struct_group()? [-Werror=attribute-warning]
> 592 | __read_overflow2_field(q_size_field, size);
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> [...]

Here is the summary with links:
- [RESEND,net-next] alx: fix OOB-read compiler warning
https://git.kernel.org/netdev/net-next/c/3a198c95c95d

You are awesome, thank you!
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