diff options
| author | Felix Fietkau <nbd@nbd.name> | 2024-09-17 14:09:42 +0300 |
|---|---|---|
| committer | Kalle Valo <kvalo@kernel.org> | 2024-09-18 16:34:00 +0300 |
| commit | 34b69548108480ebb36cb6a067974a88ec745897 (patch) | |
| tree | 79352b123c446db4708d337fe4a104e9aa6a26da | |
| parent | 5575058ba95bb016243e54e5ca3371b9884ded56 (diff) | |
| download | linux-34b69548108480ebb36cb6a067974a88ec745897.tar.xz | |
wifi: mt76: do not increase mcu skb refcount if retry is not supported
If mcu_skb_prepare_msg is not implemented, incrementing skb refcount does not
work for mcu message retry. In some cases (e.g. on SDIO), shared skbs can trigger
a BUG_ON, crashing the system.
Fix this by only incrementing refcount if retry is actually supported.
Fixes: 3688c18b65ae ("wifi: mt76: mt7915: retry mcu messages")
Closes: https://lore.kernel.org/r/d907b13a-f8be-4cb8-a0bb-560a21278041@notapiano/
Reported-by: Nícolas F. R. A. Prado <nfraprado@collabora.com> #KernelCI
Tested-by: Alper Nebi Yasak <alpernebiyasak@gmail.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://patch.msgid.link/20240917110942.22077-1-nbd@nbd.name
| -rw-r--r-- | drivers/net/wireless/mediatek/mt76/mcu.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/drivers/net/wireless/mediatek/mt76/mcu.c b/drivers/net/wireless/mediatek/mt76/mcu.c index 98da82b74094..3353012e8542 100644 --- a/drivers/net/wireless/mediatek/mt76/mcu.c +++ b/drivers/net/wireless/mediatek/mt76/mcu.c @@ -84,13 +84,16 @@ int mt76_mcu_skb_send_and_get_msg(struct mt76_dev *dev, struct sk_buff *skb, mutex_lock(&dev->mcu.mutex); if (dev->mcu_ops->mcu_skb_prepare_msg) { + orig_skb = skb; ret = dev->mcu_ops->mcu_skb_prepare_msg(dev, skb, cmd, &seq); if (ret < 0) goto out; } retry: - orig_skb = skb_get(skb); + /* orig skb might be needed for retry, mcu_skb_send_msg consumes it */ + if (orig_skb) + skb_get(orig_skb); ret = dev->mcu_ops->mcu_skb_send_msg(dev, skb, cmd, &seq); if (ret < 0) goto out; @@ -105,7 +108,7 @@ retry: do { skb = mt76_mcu_get_response(dev, expires); if (!skb && !test_bit(MT76_MCU_RESET, &dev->phy.state) && - retry++ < dev->mcu_ops->max_retry) { + orig_skb && retry++ < dev->mcu_ops->max_retry) { dev_err(dev->dev, "Retry message %08x (seq %d)\n", cmd, seq); skb = orig_skb; |