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| author |   Jia-Ju Bai <baijiaju1990@gmail.com> | 2019-12-18 17:21:55 +0800 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2019-12-18 11:57:33 -0800 |
| commit | b7ac893652cafadcf669f78452329727e4e255cc (patch) | |
| tree | 10873b8b1c06ef6e5bf1b7eabc3d59f9480175bd /net | |
| parent | net-sysfs: Call dev_hold always in rx_queue_add_kobject (diff) | |
| download | linux-dev-b7ac893652cafadcf669f78452329727e4e255cc.tar.xz linux-dev-b7ac893652cafadcf669f78452329727e4e255cc.zip | |
net: nfc: nci: fix a possible sleep-in-atomic-context bug in nci_uart_tty_receive()
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>
Diffstat (limited to 'net')
| -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 78fe622eba65..11b554ce07ff 100644 --- a/net/nfc/nci/uart.c +++ b/net/nfc/nci/uart.c @@ -346,7 +346,7 @@ 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; } |