| Message ID | 20231128082812.24483-1-dinghao.liu@zju.edu.cn (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | net/mlx5e: fix a potential double-free in fs_any_create_groups | expand |
On 28/11/2023 10:28, Dinghao Liu wrote: > When kcalloc() for ft->g succeeds but kvzalloc() for in fails, > fs_any_create_groups() will free ft->g. However, its caller > fs_any_create_table() will free ft->g again through calling > mlx5e_destroy_flow_table(), which will lead to a double-free. > Fix this by removing the kfree(ft->g) in fs_any_create_groups(). > > Fixes: 0f575c20bf06 ("net/mlx5e: Introduce Flow Steering ANY API") > Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn> > --- > drivers/net/ethernet/mellanox/mlx5/core/en/fs_tt_redirect.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/fs_tt_redirect.c b/drivers/net/ethernet/mellanox/mlx5/core/en/fs_tt_redirect.c > index be83ad9db82a..b222d23bfb9a 100644 > --- a/drivers/net/ethernet/mellanox/mlx5/core/en/fs_tt_redirect.c > +++ b/drivers/net/ethernet/mellanox/mlx5/core/en/fs_tt_redirect.c > @@ -434,7 +434,6 @@ static int fs_any_create_groups(struct mlx5e_flow_table *ft) > ft->g = kcalloc(MLX5E_FS_UDP_NUM_GROUPS, sizeof(*ft->g), GFP_KERNEL); > in = kvzalloc(inlen, GFP_KERNEL); > if (!in || !ft->g) { > - kfree(ft->g); > kvfree(in); > return -ENOMEM; > } Function fs_any_create_groups should not return failure without cleaning itself up. This is not the right fix. Freeing ft->g and setting it to NULL will do it, and will avoid the double free.
> > On 28/11/2023 10:28, Dinghao Liu wrote: > > When kcalloc() for ft->g succeeds but kvzalloc() for in fails, > > fs_any_create_groups() will free ft->g. However, its caller > > fs_any_create_table() will free ft->g again through calling > > mlx5e_destroy_flow_table(), which will lead to a double-free. > > Fix this by removing the kfree(ft->g) in fs_any_create_groups(). > > > > Fixes: 0f575c20bf06 ("net/mlx5e: Introduce Flow Steering ANY API") > > Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn> > > --- > > drivers/net/ethernet/mellanox/mlx5/core/en/fs_tt_redirect.c | 1 - > > 1 file changed, 1 deletion(-) > > > > diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/fs_tt_redirect.c b/drivers/net/ethernet/mellanox/mlx5/core/en/fs_tt_redirect.c > > index be83ad9db82a..b222d23bfb9a 100644 > > --- a/drivers/net/ethernet/mellanox/mlx5/core/en/fs_tt_redirect.c > > +++ b/drivers/net/ethernet/mellanox/mlx5/core/en/fs_tt_redirect.c > > @@ -434,7 +434,6 @@ static int fs_any_create_groups(struct mlx5e_flow_table *ft) > > ft->g = kcalloc(MLX5E_FS_UDP_NUM_GROUPS, sizeof(*ft->g), GFP_KERNEL); > > in = kvzalloc(inlen, GFP_KERNEL); > > if (!in || !ft->g) { > > - kfree(ft->g); > > kvfree(in); > > return -ENOMEM; > > } > > Function fs_any_create_groups should not return failure without cleaning > itself up. This is not the right fix. > Freeing ft->g and setting it to NULL will do it, and will avoid the > double free. Thanks for your advice! I will resend a new patch soon. Regards, Dinghao
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/fs_tt_redirect.c b/drivers/net/ethernet/mellanox/mlx5/core/en/fs_tt_redirect.c index be83ad9db82a..b222d23bfb9a 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en/fs_tt_redirect.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en/fs_tt_redirect.c @@ -434,7 +434,6 @@ static int fs_any_create_groups(struct mlx5e_flow_table *ft) ft->g = kcalloc(MLX5E_FS_UDP_NUM_GROUPS, sizeof(*ft->g), GFP_KERNEL); in = kvzalloc(inlen, GFP_KERNEL); if (!in || !ft->g) { - kfree(ft->g); kvfree(in); return -ENOMEM; }
When kcalloc() for ft->g succeeds but kvzalloc() for in fails, fs_any_create_groups() will free ft->g. However, its caller fs_any_create_table() will free ft->g again through calling mlx5e_destroy_flow_table(), which will lead to a double-free. Fix this by removing the kfree(ft->g) in fs_any_create_groups(). Fixes: 0f575c20bf06 ("net/mlx5e: Introduce Flow Steering ANY API") Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn> --- drivers/net/ethernet/mellanox/mlx5/core/en/fs_tt_redirect.c | 1 - 1 file changed, 1 deletion(-)