diff options
| author | Jia-Ju Bai <baijiaju1990@gmail.com> | 2019-12-18 17:21:55 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-01-04 13:34:20 +0100 |
| commit | fe8905d84175f58aff97e7d16f1c76ba95012ccf (patch) | |
| tree | e15642a89cf3490545542a4763f5ec9bc2e23863 | |
| parent | c86f5822a320e59bb52cde61ff99ae1515c55aaa (diff) | |
net: nfc: nci: fix a possible sleep-in-atomic-context bug in nci_uart_tty_receive()
[ Upstream commit b7ac893652cafadcf669f78452329727e4e255cc ]
The kernel may sleep while holding a spinlock.
The function call path (from bottom to top) in Linux 4.19 is:
net/nfc/nci/uart.c, 349:
nci_skb_alloc in nci_uart_default_recv_buf
net/nfc/nci/uart.c, 255:
(FUNC_PTR)nci_uart_default_recv_buf in nci_uart_tty_receive
net/nfc/nci/uart.c, 254:
spin_lock in nci_uart_tty_receive
nci_skb_alloc(GFP_KERNEL) can sleep at runtime.
(FUNC_PTR) means a function pointer is called.
To fix this bug, GFP_KERNEL is replaced with GFP_ATOMIC for
nci_skb_alloc().
This bug is found by a static analysis tool STCheck written by myself.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/nfc/nci/uart.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/nfc/nci/uart.c b/net/nfc/nci/uart.c index 21d8875673a4..c3f2faa0210e 100644 --- a/net/nfc/nci/uart.c +++ b/net/nfc/nci/uart.c @@ -355,7 +355,7 @@ static int nci_uart_default_recv_buf(struct nci_uart *nu, const u8 *data, nu->rx_packet_len = -1; nu->rx_skb = nci_skb_alloc(nu->ndev, NCI_MAX_PACKET_SIZE, - GFP_KERNEL); + GFP_ATOMIC); if (!nu->rx_skb) return -ENOMEM; } |