From: Duoming Zhou <duoming@xxxxxxxxxx>
[ 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@xxxxxxxxxx>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20220517012530.75714-1-duoming@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 ce3382be937f..b002e18f38c8 100644
--- a/net/nfc/nci/data.c
+++ b/net/nfc/nci/data.c
@@ -118,7 +118,7 @@ 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 04e55ccb3383..4fe336ff2bfa 100644
--- a/net/nfc/nci/hci.c
+++ b/net/nfc/nci/hci.c
@@ -153,7 +153,7 @@ 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;
@@ -186,7 +186,7 @@ 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;
--
2.35.1
