From: Duoming Zhou duoming@zju.edu.cn
[ Upstream commit 23dd4581350d4ffa23d58976ec46408f8f4c1e16 ]
There are sleep in atomic context bugs when the request to secure element of st-nci is timeout. The root cause is that nci_skb_alloc with GFP_KERNEL parameter is called in st_nci_se_wt_timeout which is a timer handler. The call paths that could trigger bugs are shown below:
(interrupt context 1) st_nci_se_wt_timeout nci_hci_send_event nci_hci_send_data nci_skb_alloc(..., GFP_KERNEL) //may sleep
(interrupt context 2) st_nci_se_wt_timeout nci_hci_send_event nci_hci_send_data nci_send_data nci_queue_tx_data_frags nci_skb_alloc(..., GFP_KERNEL) //may sleep
This patch changes allocation mode of nci_skb_alloc from GFP_KERNEL to GFP_ATOMIC in order to prevent atomic context sleeping. The GFP_ATOMIC flag makes memory allocation operation could be used in atomic context.
Fixes: ed06aeefdac3 ("nfc: st-nci: Rename st21nfcb to st-nci") Signed-off-by: Duoming Zhou duoming@zju.edu.cn Reviewed-by: Krzysztof Kozlowski krzysztof.kozlowski@linaro.org Link: https://lore.kernel.org/r/20220517012530.75714-1-duoming@zju.edu.cn Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/nfc/nci/data.c | 2 +- net/nfc/nci/hci.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/net/nfc/nci/data.c b/net/nfc/nci/data.c index d20383779710..b8a295dd15d8 100644 --- a/net/nfc/nci/data.c +++ b/net/nfc/nci/data.c @@ -130,7 +130,7 @@ static int nci_queue_tx_data_frags(struct nci_dev *ndev,
skb_frag = nci_skb_alloc(ndev, (NCI_DATA_HDR_SIZE + frag_len), - GFP_KERNEL); + GFP_ATOMIC); if (skb_frag == NULL) { rc = -ENOMEM; goto free_exit; diff --git a/net/nfc/nci/hci.c b/net/nfc/nci/hci.c index 5fae3f064ad0..9c37618f36c6 100644 --- a/net/nfc/nci/hci.c +++ b/net/nfc/nci/hci.c @@ -165,7 +165,7 @@ static int nci_hci_send_data(struct nci_dev *ndev, u8 pipe,
i = 0; skb = nci_skb_alloc(ndev, conn_info->max_pkt_payload_len + - NCI_DATA_HDR_SIZE, GFP_KERNEL); + NCI_DATA_HDR_SIZE, GFP_ATOMIC); if (!skb) return -ENOMEM;
@@ -198,7 +198,7 @@ static int nci_hci_send_data(struct nci_dev *ndev, u8 pipe, if (i < data_len) { skb = nci_skb_alloc(ndev, conn_info->max_pkt_payload_len + - NCI_DATA_HDR_SIZE, GFP_KERNEL); + NCI_DATA_HDR_SIZE, GFP_ATOMIC); if (!skb) return -ENOMEM;