This is a note to let you know that I've just added the patch titled
i2c: bcm2835: Avoid possible NULL ptr dereference
to the 4.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
i2c-bcm2835-avoid-possible-null-ptr-dereference.patch
and it can be found in the queue-4.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From ababb08938df7ac245d30a58b95b94ecf8dc04fc Mon Sep 17 00:00:00 2001
From: Stefan Wahren <stefan.wahren@xxxxxxxx>
Date: Thu, 16 Feb 2017 21:20:45 +0000
Subject: i2c: bcm2835: Avoid possible NULL ptr dereference
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From: Stefan Wahren <stefan.wahren@xxxxxxxx>
commit ababb08938df7ac245d30a58b95b94ecf8dc04fc upstream.
Since commit e2474541032d ("bcm2835: Fix hang for writing messages
larger than 16 bytes") the interrupt handler is prone to a possible
NULL pointer dereference. This could happen if an interrupt fires
before curr_msg is set by bcm2835_i2c_xfer_msg() and randomly occurs
on the RPi 3. Even this is an unexpected behavior the driver must
handle that with an error instead of a crash.
Reported-by: Peter Robinson <pbrobinson@xxxxxxxxx>
Fixes: e2474541032d ("bcm2835: Fix hang for writing messages larger than 16 bytes")
Signed-off-by: Stefan Wahren <stefan.wahren@xxxxxxxx>
Acked-by: Noralf Trønnes <noralf@xxxxxxxxxxx>
Signed-off-by: Wolfram Sang <wsa@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/i2c/busses/i2c-bcm2835.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--- a/drivers/i2c/busses/i2c-bcm2835.c
+++ b/drivers/i2c/busses/i2c-bcm2835.c
@@ -195,7 +195,9 @@ static irqreturn_t bcm2835_i2c_isr(int t
}
if (val & BCM2835_I2C_S_DONE) {
- if (i2c_dev->curr_msg->flags & I2C_M_RD) {
+ if (!i2c_dev->curr_msg) {
+ dev_err(i2c_dev->dev, "Got unexpected interrupt (from firmware?)\n");
+ } else if (i2c_dev->curr_msg->flags & I2C_M_RD) {
bcm2835_drain_rxfifo(i2c_dev);
val = bcm2835_i2c_readl(i2c_dev, BCM2835_I2C_S);
}
Patches currently in stable-queue which might be from stefan.wahren@xxxxxxxx are
queue-4.10/i2c-bcm2835-avoid-possible-null-ptr-dereference.patch