a71a29f50d
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>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.