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authorJia-Ju Bai <baijiaju1990@gmail.com>2019-12-18 17:21:55 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-01-04 13:34:20 +0100
commitfe8905d84175f58aff97e7d16f1c76ba95012ccf (patch)
treee15642a89cf3490545542a4763f5ec9bc2e23863 /net/nfc
parentc86f5822a320e59bb52cde61ff99ae1515c55aaa (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>
Diffstat (limited to 'net/nfc')
-rw-r--r--net/nfc/nci/uart.c2
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;
}