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Message-Id: <20220523165751.029587860@linuxfoundation.org>
Date: Mon, 23 May 2022 19:05:07 +0200
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-kernel@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
stable@...r.kernel.org, Duoming Zhou <duoming@....edu.cn>,
Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>,
Jakub Kicinski <kuba@...nel.org>,
Sasha Levin <sashal@...nel.org>
Subject: [PATCH 4.14 18/33] NFC: nci: fix sleep in atomic context bugs caused by nci_skb_alloc
From: Duoming Zhou <duoming@....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@....edu.cn>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
Link: https://lore.kernel.org/r/20220517012530.75714-1-duoming@zju.edu.cn
Signed-off-by: Jakub Kicinski <kuba@...nel.org>
Signed-off-by: Sasha Levin <sashal@...nel.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 5405d073804c..9e3f9460f14f 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 c972c212e7ca..e5c5cff33236 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;
--
2.35.1
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