From: Fedor Pchelkin pchelkin@ispras.ru
[ Upstream commit 25ff6f8a5a3b8dc48e8abda6f013e8cc4b14ffea ]
The callback context for sending/receiving APDUs to/from the selected secure element is allocated inside nfc_genl_se_io and supposed to be eventually freed in se_io_cb callback function. However, there are several error paths where the bwi_timer is not charged to call se_io_cb later, and the cb_context is leaked.
The patch proposes to free the cb_context explicitly on those error paths.
At the moment we can't simply check 'dev->ops->se_io()' return value as it may be negative in both cases: when the timer was charged and was not.
Fixes: 5ce3f32b5264 ("NFC: netlink: SE API implementation") Reported-by: syzbot+df64c0a2e8d68e78a4fa@syzkaller.appspotmail.com Signed-off-by: Fedor Pchelkin pchelkin@ispras.ru Signed-off-by: Alexey Khoroshilov khoroshilov@ispras.ru Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/nfc/st-nci/se.c | 6 ++++++ drivers/nfc/st21nfca/se.c | 6 ++++++ net/nfc/netlink.c | 4 ++++ 3 files changed, 16 insertions(+)
diff --git a/drivers/nfc/st-nci/se.c b/drivers/nfc/st-nci/se.c index 37d397aae9b9d..a14afceaf5e92 100644 --- a/drivers/nfc/st-nci/se.c +++ b/drivers/nfc/st-nci/se.c @@ -664,6 +664,12 @@ int st_nci_se_io(struct nci_dev *ndev, u32 se_idx, ST_NCI_EVT_TRANSMIT_DATA, apdu, apdu_length); default: + /* Need to free cb_context here as at the moment we can't + * clearly indicate to the caller if the callback function + * would be called (and free it) or not. In both cases a + * negative value may be returned to the caller. + */ + kfree(cb_context); return -ENODEV; } } diff --git a/drivers/nfc/st21nfca/se.c b/drivers/nfc/st21nfca/se.c index d416365042462..6a1d3b2752fbf 100644 --- a/drivers/nfc/st21nfca/se.c +++ b/drivers/nfc/st21nfca/se.c @@ -236,6 +236,12 @@ int st21nfca_hci_se_io(struct nfc_hci_dev *hdev, u32 se_idx, ST21NFCA_EVT_TRANSMIT_DATA, apdu, apdu_length); default: + /* Need to free cb_context here as at the moment we can't + * clearly indicate to the caller if the callback function + * would be called (and free it) or not. In both cases a + * negative value may be returned to the caller. + */ + kfree(cb_context); return -ENODEV; } } diff --git a/net/nfc/netlink.c b/net/nfc/netlink.c index 610caea4feec8..3f4785be066a8 100644 --- a/net/nfc/netlink.c +++ b/net/nfc/netlink.c @@ -1442,7 +1442,11 @@ static int nfc_se_io(struct nfc_dev *dev, u32 se_idx, rc = dev->ops->se_io(dev, se_idx, apdu, apdu_length, cb, cb_context);
+ device_unlock(&dev->dev); + return rc; + error: + kfree(cb_context); device_unlock(&dev->dev); return rc; }