From: Stephan Gerhold stephan@gerhold.net
[ Upstream commit a71a29f50de1ef97ab55c151a1598eb12dde379d ]
I2C communication errors (-EREMOTEIO) during the IRQ handler of nxp-nci result in a NULL pointer dereference at the moment:
BUG: kernel NULL pointer dereference, address: 0000000000000000 Oops: 0002 [#1] PREEMPT SMP NOPTI CPU: 1 PID: 355 Comm: irq/137-nxp-nci Not tainted 5.4.0-rc6 #1 RIP: 0010:skb_queue_tail+0x25/0x50 Call Trace: nci_recv_frame+0x36/0x90 [nci] nxp_nci_i2c_irq_thread_fn+0xd1/0x285 [nxp_nci_i2c] ? preempt_count_add+0x68/0xa0 ? irq_forced_thread_fn+0x80/0x80 irq_thread_fn+0x20/0x60 irq_thread+0xee/0x180 ? wake_threads_waitq+0x30/0x30 kthread+0xfb/0x130 ? irq_thread_check_affinity+0xd0/0xd0 ? kthread_park+0x90/0x90 ret_from_fork+0x1f/0x40
Afterward the kernel must be rebooted to work properly again.
This happens because it attempts to call nci_recv_frame() with skb == NULL. However, unlike nxp_nci_fw_recv_frame(), nci_recv_frame() does not have any NULL checks for skb, causing the NULL pointer dereference.
Change the code to call only nxp_nci_fw_recv_frame() in case of an error. Make sure to log it so it is obvious that a communication error occurred. The error above then becomes:
nxp-nci_i2c i2c-NXP1001:00: NFC: Read failed with error -121 nci: __nci_request: wait_for_completion_interruptible_timeout failed 0 nxp-nci_i2c i2c-NXP1001:00: NFC: Read failed with error -121
Fixes: 6be88670fc59 ("NFC: nxp-nci_i2c: Add I2C support to NXP NCI driver") Signed-off-by: Stephan Gerhold stephan@gerhold.net Reviewed-by: Andy Shevchenko andriy.shevchenko@linux.intel.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/nfc/nxp-nci/i2c.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/nfc/nxp-nci/i2c.c b/drivers/nfc/nxp-nci/i2c.c index 0b1122cb5d0c8..b505a6e135b75 100644 --- a/drivers/nfc/nxp-nci/i2c.c +++ b/drivers/nfc/nxp-nci/i2c.c @@ -239,8 +239,10 @@ static irqreturn_t nxp_nci_i2c_irq_thread_fn(int irq, void *phy_id)
if (r == -EREMOTEIO) { phy->hard_fault = r; - skb = NULL; - } else if (r < 0) { + if (info->mode == NXP_NCI_MODE_FW) + nxp_nci_fw_recv_frame(phy->ndev, NULL); + } + if (r < 0) { nfc_err(&client->dev, "Read failed with error %d\n", r); goto exit_irq_handled; }