Both of these list traversals use list_for_each_entry_safe(), yet drop the lock protecting the list during the traversal. Because the _safe() iterator stores a pointer to the next list node locally so the current node can be deleted, dropping the lock this way means the next "cached" list_head might be freed by another caller, leading the iterator to dereference pointers in freed memory after reacquiring the lock. Fix by moving to-be-deleted objects to an on-stack list before actually deleting them, so the lock can be held for the entire traversal. This is a bit ugly, because mwifiex_del_rx_reorder_entry() will still take the rx_reorder_tbl_lock to delete the item from the two on-stack lists introduced in this patch. But that is just ugly, not wrong, and the function has other callers... making the locking conditional seems strictly uglier. I discovered this bug while studying the new "nxpwifi" driver, which was sent to the mailing list about a month ago: https://lore.kernel.org/lkml/20240621075208.513497-1-yu-hao.lin@xxxxxxx/ ...but it turns out the new 11n_rxreorder.c in nxpwifi is essentially exactly identical to mwifiex, save for s/mwifiex/nxpwifi/, so I wanted to pass along a bugfix for the original driver as well. I only have an IW612, so this patch was only tested on "nxpwifi". Signed-off-by: Calvin Owens <calvin@xxxxxxxxxx> --- .../wireless/marvell/mwifiex/11n_rxreorder.c | 26 +++++++++---------- 1 file changed, 12 insertions(+), 14 deletions(-) diff --git a/drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c b/drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c index 10690e82358b..fbaecfd32429 100644 --- a/drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c +++ b/drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c @@ -249,20 +249,20 @@ mwifiex_11n_get_rx_reorder_tbl(struct mwifiex_private *priv, int tid, u8 *ta) void mwifiex_11n_del_rx_reorder_tbl_by_ta(struct mwifiex_private *priv, u8 *ta) { struct mwifiex_rx_reorder_tbl *tbl, *tmp; + LIST_HEAD(tmplist); if (!ta) return; spin_lock_bh(&priv->rx_reorder_tbl_lock); - list_for_each_entry_safe(tbl, tmp, &priv->rx_reorder_tbl_ptr, list) { - if (!memcmp(tbl->ta, ta, ETH_ALEN)) { - spin_unlock_bh(&priv->rx_reorder_tbl_lock); - mwifiex_del_rx_reorder_entry(priv, tbl); - spin_lock_bh(&priv->rx_reorder_tbl_lock); - } - } + list_for_each_entry_safe(tbl, tmp, &priv->rx_reorder_tbl_ptr, list) + if (!memcmp(tbl->ta, ta, ETH_ALEN)) + list_move_tail(&tbl->list, &tmplist); spin_unlock_bh(&priv->rx_reorder_tbl_lock); + list_for_each_entry_safe(tbl, tmp, &tmplist, list) + mwifiex_del_rx_reorder_entry(priv, tbl); + return; } @@ -785,17 +785,15 @@ void mwifiex_11n_ba_stream_timeout(struct mwifiex_private *priv, void mwifiex_11n_cleanup_reorder_tbl(struct mwifiex_private *priv) { struct mwifiex_rx_reorder_tbl *del_tbl_ptr, *tmp_node; + LIST_HEAD(tmplist); spin_lock_bh(&priv->rx_reorder_tbl_lock); - list_for_each_entry_safe(del_tbl_ptr, tmp_node, - &priv->rx_reorder_tbl_ptr, list) { - spin_unlock_bh(&priv->rx_reorder_tbl_lock); - mwifiex_del_rx_reorder_entry(priv, del_tbl_ptr); - spin_lock_bh(&priv->rx_reorder_tbl_lock); - } - INIT_LIST_HEAD(&priv->rx_reorder_tbl_ptr); + list_splice_tail_init(&priv->rx_reorder_tbl_ptr, &tmplist); spin_unlock_bh(&priv->rx_reorder_tbl_lock); + list_for_each_entry_safe(del_tbl_ptr, tmp_node, &tmplist, list) + mwifiex_del_rx_reorder_entry(priv, del_tbl_ptr); + mwifiex_reset_11n_rx_seq_num(priv); } -- 2.39.2
