From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Jia-Ju Bai <baijiaju1990@gmail.com>,
"David S . Miller" <davem@davemloft.net>,
Sasha Levin <sashal@kernel.org>,
netdev@vger.kernel.org
Subject: [PATCH AUTOSEL 4.4 21/25] net: nfc: nci: fix a possible sleep-in-atomic-context bug in nci_uart_tty_receive()
Date: Fri, 27 Dec 2019 13:15:45 -0500 [thread overview]
Message-ID: <20191227181549.8040-21-sashal@kernel.org> (raw)
In-Reply-To: <20191227181549.8040-1-sashal@kernel.org>
From: Jia-Ju Bai <baijiaju1990@gmail.com>
[ 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: Sasha Levin <sashal@kernel.org>
---
net/nfc/nci/uart.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
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;
}
--
2.20.1
next prev parent reply other threads:[~2019-12-27 18:16 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20191227181549.8040-1-sashal@kernel.org>
2019-12-27 18:15 ` [PATCH AUTOSEL 4.4 02/25] netfilter: ctnetlink: netns exit must wait for callbacks Sasha Levin
2019-12-27 18:15 ` [PATCH AUTOSEL 4.4 05/25] netfilter: bridge: make sure to pull arp header in br_nf_forward_arp() Sasha Levin
2019-12-27 18:15 ` [PATCH AUTOSEL 4.4 06/25] af_packet: set defaule value for tmo Sasha Levin
2019-12-27 18:15 ` [PATCH AUTOSEL 4.4 07/25] fjes: fix missed check in fjes_acpi_add Sasha Levin
2019-12-27 18:15 ` [PATCH AUTOSEL 4.4 10/25] net: usb: lan78xx: Fix suspend/resume PHY register access error Sasha Levin
2019-12-27 18:15 ` [PATCH AUTOSEL 4.4 12/25] 6pack,mkiss: fix possible deadlock Sasha Levin
2019-12-27 18:15 ` [PATCH AUTOSEL 4.4 13/25] bnx2x: Do not handle requests from VFs after parity Sasha Levin
2019-12-27 18:15 ` [PATCH AUTOSEL 4.4 14/25] bnx2x: Fix logic to get total no. of PFs per engine Sasha Levin
2019-12-27 18:15 ` [PATCH AUTOSEL 4.4 15/25] net: usb: lan78xx: Fix error message format specifier Sasha Levin
2019-12-27 18:15 ` [PATCH AUTOSEL 4.4 16/25] rfkill: Fix incorrect check to avoid NULL pointer dereference Sasha Levin
2019-12-27 18:15 ` [PATCH AUTOSEL 4.4 20/25] net: qlogic: Fix error paths in ql_alloc_large_buffers() Sasha Levin
2019-12-27 18:15 ` Sasha Levin [this message]
2019-12-27 18:15 ` [PATCH AUTOSEL 4.4 23/25] net: hisilicon: Fix a BUG trigered by wrong bytes_compl Sasha Levin
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