Hi,
On Sun, 20 Aug 2023 at 13:20, Ping-Ke Shih <pkshih@xxxxxxxxxxx> wrote:
>
> The commit 06470f7468c8 ("mac80211: add API to allow filtering frames in BA sessions")
> adds reorder_buf_filtered to mark frames filtered by firmware, and it can
> only work correctly if hw.max_rx_aggregation_subframes <= 64 because
> maximum BlockAck is 64 at that moment.
>
> However, new HE or EHT devices can support BlockAck number up to 256 or
> 1024, and leads UBSAN warning:
>
> UBSAN: shift-out-of-bounds in net/mac80211/rx.c:1129:39
> shift exponent 215 is too large for 64-bit type 'long long unsigned int'
> Call Trace:
> <IRQ>
> dump_stack_lvl+0x48/0x70
> dump_stack+0x10/0x20
> __ubsan_handle_shift_out_of_bounds+0x1ac/0x360
> ieee80211_release_reorder_frame.constprop.0.cold+0x64/0x69 [mac80211]
> ieee80211_sta_reorder_release+0x9c/0x400 [mac80211]
> ieee80211_prepare_and_rx_handle+0x1234/0x1420 [mac80211]
> ? __pfx_jhash+0x10/0x10
> ? rht_key_get_hash.isra.0+0x19/0x30 [mac80211]
> ieee80211_rx_list+0xaef/0xf60 [mac80211]
> ? kfree_skbmem+0x58/0xb0
> ? rtw89_vif_rx_stats_iter+0x2bb/0x2e1 [rtw89_core]
> ieee80211_rx_napi+0x53/0xd0 [mac80211]
>
> Since only old hardware that supports <=64 BlockAck uses
> ieee80211_mark_rx_ba_filtered_frames(), limit the use as it is, so add a
> WARN_ONCE() and comment to note to avoid using this function if hardware
> capability is not suitable.
>
> Signed-off-by: Ping-Ke Shih <pkshih@xxxxxxxxxxx>
> ---
> include/net/mac80211.h | 1 +
> net/mac80211/rx.c | 12 ++++++++++--
> 2 files changed, 11 insertions(+), 2 deletions(-)
>
> diff --git a/include/net/mac80211.h b/include/net/mac80211.h
> index 3a8a2d2c58c3..2a55ae932c56 100644
> --- a/include/net/mac80211.h
> +++ b/include/net/mac80211.h
> @@ -6612,6 +6612,7 @@ void ieee80211_stop_rx_ba_session(struct ieee80211_vif *vif, u16 ba_rx_bitmap,
> * marks frames marked in the bitmap as having been filtered. Afterwards, it
> * checks if any frames in the window starting from @ssn can now be released
> * (in case they were only waiting for frames that were filtered.)
> + * (Only work correctly if @max_rx_aggregation_subframes <= 64 frames)
> */
> void ieee80211_mark_rx_ba_filtered_frames(struct ieee80211_sta *pubsta, u8 tid,
> u16 ssn, u64 filtered,
> diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
> index 4f707d2a160f..0af2599c17e8 100644
> --- a/net/mac80211/rx.c
> +++ b/net/mac80211/rx.c
> @@ -1083,7 +1083,8 @@ static inline bool ieee80211_rx_reorder_ready(struct tid_ampdu_rx *tid_agg_rx,
> struct sk_buff *tail = skb_peek_tail(frames);
> struct ieee80211_rx_status *status;
>
> - if (tid_agg_rx->reorder_buf_filtered & BIT_ULL(index))
> + if (tid_agg_rx->reorder_buf_filtered &&
> + tid_agg_rx->reorder_buf_filtered & BIT_ULL(index))
While it will silence the UBSAN warning, unless you know why the code
was written this way it will look like a pointless micro-optimization.
So I suggest changing the condition to
if (index < BITS_PER_LONG_LONG &&
tid_agg_rx->reorder_buf_filtered & BIT_ULL(index))
to make it more obvious what the intention of the extra condition is.
> return true;
>
> if (!tail)
> @@ -1124,7 +1125,8 @@ static void ieee80211_release_reorder_frame(struct ieee80211_sub_if_data *sdata,
> }
>
> no_frame:
> - tid_agg_rx->reorder_buf_filtered &= ~BIT_ULL(index);
> + if (tid_agg_rx->reorder_buf_filtered)
> + tid_agg_rx->reorder_buf_filtered &= ~BIT_ULL(index);
likewise
> tid_agg_rx->head_seq_num = ieee80211_sn_inc(tid_agg_rx->head_seq_num);
> }
>
> @@ -4264,6 +4266,7 @@ void ieee80211_mark_rx_ba_filtered_frames(struct ieee80211_sta *pubsta, u8 tid,
> u16 ssn, u64 filtered,
> u16 received_mpdus)
> {
> + struct ieee80211_local *local;
> struct sta_info *sta;
> struct tid_ampdu_rx *tid_agg_rx;
> struct sk_buff_head frames;
> @@ -4281,6 +4284,11 @@ void ieee80211_mark_rx_ba_filtered_frames(struct ieee80211_sta *pubsta, u8 tid,
>
> sta = container_of(pubsta, struct sta_info, sta);
>
> + local = sta->sdata->local;
> + WARN_ONCE(local->hw.max_rx_aggregation_subframes > 64,
> + "RX BA marker can't support max_rx_aggregation_subframes %u > 64\n",
> + local->hw.max_rx_aggregation_subframes);
And maybe use BITS_PER_LONG_LONG here as well.
Or introduce your own macro. Not sure what's nicer.
> +
> if (!ieee80211_rx_data_set_sta(&rx, sta, -1))
> return;
>
> --
> 2.25.1
>
Regards,
Jonas
