5.4-stable review patch. If anyone has any objections, please let me know.
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From: Juraj Šarinay juraj@sarinay.com
[ Upstream commit 21f82062d0f241e55dd59eb630e8710862cc90b4 ]
An exchange with a NFC target must complete within NCI_DATA_TIMEOUT. A delay of 700 ms is not sufficient for cryptographic operations on smart cards. CardOS 6.0 may need up to 1.3 seconds to perform 256-bit ECDH or 3072-bit RSA. To prevent brute-force attacks, passports and similar documents introduce even longer delays into access control protocols (BAC/PACE).
The timeout should be higher, but not too much. The expiration allows us to detect that a NFC target has disappeared.
Signed-off-by: Juraj Šarinay juraj@sarinay.com Reviewed-by: Krzysztof Kozlowski krzysztof.kozlowski@linaro.org Link: https://patch.msgid.link/20250902113630.62393-1-juraj@sarinay.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- include/net/nfc/nci_core.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/net/nfc/nci_core.h b/include/net/nfc/nci_core.h index 004e49f748419..beea7e014b157 100644 --- a/include/net/nfc/nci_core.h +++ b/include/net/nfc/nci_core.h @@ -52,7 +52,7 @@ enum nci_state { #define NCI_RF_DISC_SELECT_TIMEOUT 5000 #define NCI_RF_DEACTIVATE_TIMEOUT 30000 #define NCI_CMD_TIMEOUT 5000 -#define NCI_DATA_TIMEOUT 700 +#define NCI_DATA_TIMEOUT 3000
struct nci_dev;