On 8/1/2019 4:52 PM, Qian Cai wrote:
> The commit 069d11465a80 ("net/mlx5e: RX, Enhance legacy Receive Queue
> memory scheme") introduced an undefined behaviour below due to
> "frag->last_in_page" is only initialized in mlx5e_init_frags_partition()
> when,
>
> if (next_frag.offset + frag_info[f].frag_stride > PAGE_SIZE)
>
> or after bailed out the loop,
>
> for (i = 0; i < mlx5_wq_cyc_get_size(&rq->wqe.wq); i++)
>
> As the result, there could be some "frag" have uninitialized
> value of "last_in_page".
>
> Later, get_frag() obtains those "frag" and check "frag->last_in_page" in
> mlx5e_put_rx_frag() and triggers the error during boot. Fix it by always
> initializing "frag->last_in_page" to "false" in
> mlx5e_init_frags_partition().
>
> UBSAN: Undefined behaviour in
> drivers/net/ethernet/mellanox/mlx5/core/en_rx.c:325:12
> load of value 170 is not a valid value for type 'bool' (aka '_Bool')
> Call trace:
> dump_backtrace+0x0/0x264
> show_stack+0x20/0x2c
> dump_stack+0xb0/0x104
> __ubsan_handle_load_invalid_value+0x104/0x128
> mlx5e_handle_rx_cqe+0x8e8/0x12cc [mlx5_core]
> mlx5e_poll_rx_cq+0xca8/0x1a94 [mlx5_core]
> mlx5e_napi_poll+0x17c/0xa30 [mlx5_core]
> net_rx_action+0x248/0x940
> __do_softirq+0x350/0x7b8
> irq_exit+0x200/0x26c
> __handle_domain_irq+0xc8/0x128
> gic_handle_irq+0x138/0x228
> el1_irq+0xb8/0x140
> arch_cpu_idle+0x1a4/0x348
> do_idle+0x114/0x1b0
> cpu_startup_entry+0x24/0x28
> rest_init+0x1ac/0x1dc
> arch_call_rest_init+0x10/0x18
> start_kernel+0x4d4/0x57c
>
> Fixes: 069d11465a80 ("net/mlx5e: RX, Enhance legacy Receive Queue memory
> scheme")
> Signed-off-by: Qian Cai <c...@lca.pw>
> ---
>
> v2: zero-init the whole struct instead per Tariq.
>
> drivers/net/ethernet/mellanox/mlx5/core/en_main.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
> b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
> index 47eea6b3a1c3..e1810c03a510 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
> @@ -331,12 +331,11 @@ static inline u64 mlx5e_get_mpwqe_offset(struct
> mlx5e_rq *rq, u16 wqe_ix)
>
> static void mlx5e_init_frags_partition(struct mlx5e_rq *rq)
> {
> - struct mlx5e_wqe_frag_info next_frag, *prev;
> + struct mlx5e_wqe_frag_info next_frag = {};
> + struct mlx5e_wqe_frag_info *prev = NULL;
> int i;
>
> next_frag.di = &rq->wqe.di[0];
> - next_frag.offset = 0;
> - prev = NULL;
>
> for (i = 0; i < mlx5_wq_cyc_get_size(&rq->wqe.wq); i++) {
> struct mlx5e_rq_frag_info *frag_info = &rq->wqe.info.arr[0];
>
Reviewed-by: Tariq Toukan <tar...@mellanox.com>
Thanks.
