diff options
| author | Stefan Wahren <stefan.wahren@i2se.com> | 2017-02-16 21:20:45 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-11-10 07:42:45 -0800 |
| commit | 08ae439c95d164e9c0022e0511f4fbb4deffd220 (patch) | |
| tree | a06917c351c660b227058216ab3e49be73ee0c7e /drivers/i2c | |
| parent | 9e431e0ca94716a5470f81da2e9cc9aeed3a2d09 (diff) | |
i2c: bcm2835: Avoid possible NULL ptr dereference
[ Upstream commit ababb08938df7ac245d30a58b95b94ecf8dc04fc ]
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@gmail.com>
Fixes: e2474541032d ("bcm2835: Fix hang for writing messages larger than 16 bytes")
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Acked-by: Noralf Trønnes <noralf@tronnes.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/i2c-bcm2835.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/i2c/busses/i2c-bcm2835.c b/drivers/i2c/busses/i2c-bcm2835.c index f283b714aa79..7ed09865cb4b 100644 --- a/drivers/i2c/busses/i2c-bcm2835.c +++ b/drivers/i2c/busses/i2c-bcm2835.c @@ -128,7 +128,9 @@ static irqreturn_t bcm2835_i2c_isr(int this_irq, void *data) } 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); } |