2024-06-04 10:08:34

by Aleksandr Mishin

[permalink] [raw]
Subject: [PATCH net] net/mlx5: Fix tainted pointer delete is case of flow rules creation fail

In case of flow rule creation fail in mlx5_lag_create_port_sel_table(),
instead of previously created rules, the tainted pointer is deleted
deveral times.
Fix this bug by using correct flow rules pointers.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 352899f384d4 ("net/mlx5: Lag, use buckets in hash mode")
Signed-off-by: Aleksandr Mishin <[email protected]>
---
drivers/net/ethernet/mellanox/mlx5/core/lag/port_sel.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/lag/port_sel.c b/drivers/net/ethernet/mellanox/mlx5/core/lag/port_sel.c
index c16b462ddedf..ab2717012b79 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/lag/port_sel.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/lag/port_sel.c
@@ -88,9 +88,13 @@ static int mlx5_lag_create_port_sel_table(struct mlx5_lag *ldev,
&dest, 1);
if (IS_ERR(lag_definer->rules[idx])) {
err = PTR_ERR(lag_definer->rules[idx]);
- while (i--)
- while (j--)
+ do {
+ while (j--) {
+ idx = i * ldev->buckets + j;
mlx5_del_flow_rules(lag_definer->rules[idx]);
+ }
+ j = ldev->buckets;
+ } while (i--);
goto destroy_fg;
}
}
--
2.30.2



2024-06-04 22:00:15

by Jacob Keller

[permalink] [raw]
Subject: Re: [PATCH net] net/mlx5: Fix tainted pointer delete is case of flow rules creation fail



On 6/4/2024 3:05 AM, Aleksandr Mishin wrote:
> In case of flow rule creation fail in mlx5_lag_create_port_sel_table(),
> instead of previously created rules, the tainted pointer is deleted
> deveral times.
> Fix this bug by using correct flow rules pointers.
>
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
>
> Fixes: 352899f384d4 ("net/mlx5: Lag, use buckets in hash mode")
> Signed-off-by: Aleksandr Mishin <[email protected]>
> ---
> drivers/net/ethernet/mellanox/mlx5/core/lag/port_sel.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/lag/port_sel.c b/drivers/net/ethernet/mellanox/mlx5/core/lag/port_sel.c
> index c16b462ddedf..ab2717012b79 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/lag/port_sel.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/lag/port_sel.c
> @@ -88,9 +88,13 @@ static int mlx5_lag_create_port_sel_table(struct mlx5_lag *ldev,
> &dest, 1);
> if (IS_ERR(lag_definer->rules[idx])) {
> err = PTR_ERR(lag_definer->rules[idx]);
> - while (i--)
> - while (j--)
> + do {
> + while (j--) {
> + idx = i * ldev->buckets + j;
> mlx5_del_flow_rules(lag_definer->rules[idx]);
> + }
> + j = ldev->buckets;
> + } while (i--);

So, before the code was:

while (i--)
while (j--)
mlx5_del_flow_rules(lag_definer->rules[idx]);

That just calls mlx5_del_flow_rules a bunch of times but keeps using the
wrong index, which is obviously wrong.

The new fix is to calculate the index properly (hence the switch to a do
{ } while (0) loop, so that we properly delete all of the older rules
rather than calling mlx5_del_flow_rules multiple times on the wrong index.

Makes sense.

Reviewed-by: Jacob Keller <[email protected]>

> goto destroy_fg;
> }
> }

2024-06-05 05:14:30

by Tariq Toukan

[permalink] [raw]
Subject: Re: [PATCH net] net/mlx5: Fix tainted pointer delete is case of flow rules creation fail



On 04/06/2024 13:05, Aleksandr Mishin wrote:
> In case of flow rule creation fail in mlx5_lag_create_port_sel_table(),
> instead of previously created rules, the tainted pointer is deleted
> deveral times.
> Fix this bug by using correct flow rules pointers.
>
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
>
> Fixes: 352899f384d4 ("net/mlx5: Lag, use buckets in hash mode")
> Signed-off-by: Aleksandr Mishin <[email protected]>
> ---
> drivers/net/ethernet/mellanox/mlx5/core/lag/port_sel.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/lag/port_sel.c b/drivers/net/ethernet/mellanox/mlx5/core/lag/port_sel.c
> index c16b462ddedf..ab2717012b79 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/lag/port_sel.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/lag/port_sel.c
> @@ -88,9 +88,13 @@ static int mlx5_lag_create_port_sel_table(struct mlx5_lag *ldev,
> &dest, 1);
> if (IS_ERR(lag_definer->rules[idx])) {
> err = PTR_ERR(lag_definer->rules[idx]);
> - while (i--)
> - while (j--)
> + do {
> + while (j--) {
> + idx = i * ldev->buckets + j;
> mlx5_del_flow_rules(lag_definer->rules[idx]);
> + }
> + j = ldev->buckets;
> + } while (i--);
> goto destroy_fg;
> }
> }

Reviewed-by: Tariq Toukan <[email protected]>




Thanks.

2024-06-05 21:40:10

by patchwork-bot+netdevbpf

[permalink] [raw]
Subject: Re: [PATCH net] net/mlx5: Fix tainted pointer delete is case of flow rules creation fail

Hello:

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

On Tue, 4 Jun 2024 13:05:52 +0300 you wrote:
> In case of flow rule creation fail in mlx5_lag_create_port_sel_table(),
> instead of previously created rules, the tainted pointer is deleted
> deveral times.
> Fix this bug by using correct flow rules pointers.
>
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
>
> [...]

Here is the summary with links:
- [net] net/mlx5: Fix tainted pointer delete is case of flow rules creation fail
https://git.kernel.org/netdev/net/c/229bedbf62b1

You are awesome, thank you!
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