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| author | Duoming Zhou <duoming@zju.edu.cn> | 2022-05-17 04:25:30 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2022-05-18 03:55:53 +0300 |
| commit | 23dd4581350d4ffa23d58976ec46408f8f4c1e16 (patch) | |
| tree | 7a5c5ce71ec4c15d5e35d434cb55004059076a33 /net | |
| parent | 5361448e45fac6fb96738df748229432a62d78b6 (diff) | |
| download | linux-23dd4581350d4ffa23d58976ec46408f8f4c1e16.tar.xz | |
NFC: nci: fix sleep in atomic context bugs caused by nci_skb_alloc
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>
Diffstat (limited to 'net')
| -rw-r--r-- | net/nfc/nci/data.c | 2 | ||||
| -rw-r--r-- | 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 6055dc9a82aa..aa5e712adf07 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 19703a649b5a..78c4b6addf15 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; @@ -184,7 +184,7 @@ 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; |