| Message ID | 20220729110216.557010-1-zheyuma97@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | i2c: ismt: Fix an out-of-bounds bug in ismt_access() | expand |
On Fri, Jul 29, 2022 at 07:02:16PM +0800, Zheyu Ma wrote: > When the driver does not check the data from the user, the variable > 'data->block[0]' may be very large to cause an out-of-bounds bug. > > The following log can reveal it: > > [ 33.995542] i2c i2c-1: ioctl, cmd=0x720, arg=0x7ffcb3dc3a20 > [ 33.995978] ismt_smbus 0000:00:05.0: I2C_SMBUS_BLOCK_DATA: WRITE > [ 33.996475] ================================================================== > [ 33.996995] BUG: KASAN: out-of-bounds in ismt_access.cold+0x374/0x214b > [ 33.997473] Read of size 18446744073709551615 at addr ffff88810efcfdb1 by task ismt_poc/485 > [ 33.999450] Call Trace: > [ 34.001849] memcpy+0x20/0x60 > [ 34.002077] ismt_access.cold+0x374/0x214b > [ 34.003382] __i2c_smbus_xfer+0x44f/0xfb0 > [ 34.004007] i2c_smbus_xfer+0x10a/0x390 > [ 34.004291] i2cdev_ioctl_smbus+0x2c8/0x710 > [ 34.005196] i2cdev_ioctl+0x5ec/0x74c > > Fix this bug by checking the size of 'data->block[0]' first. > > Fixes: 13f35ac14cd0 ("i2c: Adding support for Intel iSMT SMBus 2.0 host controller") > Signed-off-by: Zheyu Ma <zheyuma97@gmail.com> This patch has not been applied, and I don't see a response to it either. Is there a problem with it, or did it get lost ? Thanks, Guenter > --- > drivers/i2c/busses/i2c-ismt.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/i2c/busses/i2c-ismt.c b/drivers/i2c/busses/i2c-ismt.c > index 6078fa0c0d48..63120c41354c 100644 > --- a/drivers/i2c/busses/i2c-ismt.c > +++ b/drivers/i2c/busses/i2c-ismt.c > @@ -509,6 +509,9 @@ static int ismt_access(struct i2c_adapter *adap, u16 addr, > if (read_write == I2C_SMBUS_WRITE) { > /* Block Write */ > dev_dbg(dev, "I2C_SMBUS_BLOCK_DATA: WRITE\n"); > + if (data->block[0] < 1 || data->block[0] > I2C_SMBUS_BLOCK_MAX) > + return -EINVAL; > + > dma_size = data->block[0] + 1; > dma_direction = DMA_TO_DEVICE; > desc->wr_len_cmd = dma_size; > -- > 2.25.1 >
On Thu, Sep 08, 2022 at 10:22:54AM -0700, Guenter Roeck wrote: > On Fri, Jul 29, 2022 at 07:02:16PM +0800, Zheyu Ma wrote: > > When the driver does not check the data from the user, the variable > > 'data->block[0]' may be very large to cause an out-of-bounds bug. > > > > The following log can reveal it: > > > > [ 33.995542] i2c i2c-1: ioctl, cmd=0x720, arg=0x7ffcb3dc3a20 > > [ 33.995978] ismt_smbus 0000:00:05.0: I2C_SMBUS_BLOCK_DATA: WRITE > > [ 33.996475] ================================================================== > > [ 33.996995] BUG: KASAN: out-of-bounds in ismt_access.cold+0x374/0x214b > > [ 33.997473] Read of size 18446744073709551615 at addr ffff88810efcfdb1 by task ismt_poc/485 > > [ 33.999450] Call Trace: > > [ 34.001849] memcpy+0x20/0x60 > > [ 34.002077] ismt_access.cold+0x374/0x214b > > [ 34.003382] __i2c_smbus_xfer+0x44f/0xfb0 > > [ 34.004007] i2c_smbus_xfer+0x10a/0x390 > > [ 34.004291] i2cdev_ioctl_smbus+0x2c8/0x710 > > [ 34.005196] i2cdev_ioctl+0x5ec/0x74c > > > > Fix this bug by checking the size of 'data->block[0]' first. > > > > Fixes: 13f35ac14cd0 ("i2c: Adding support for Intel iSMT SMBus 2.0 host controller") > > Signed-off-by: Zheyu Ma <zheyuma97@gmail.com> > > This patch has not been applied, and I don't see a response to it either. > Is there a problem with it, or did it get lost ? Seth is currently looking for a co-maintainer to assist him with this driver.
On Fri, Jul 29, 2022 at 07:02:16PM +0800, Zheyu Ma wrote: > When the driver does not check the data from the user, the variable > 'data->block[0]' may be very large to cause an out-of-bounds bug. > > The following log can reveal it: > > [ 33.995542] i2c i2c-1: ioctl, cmd=0x720, arg=0x7ffcb3dc3a20 > [ 33.995978] ismt_smbus 0000:00:05.0: I2C_SMBUS_BLOCK_DATA: WRITE > [ 33.996475] ================================================================== > [ 33.996995] BUG: KASAN: out-of-bounds in ismt_access.cold+0x374/0x214b > [ 33.997473] Read of size 18446744073709551615 at addr ffff88810efcfdb1 by task ismt_poc/485 > [ 33.999450] Call Trace: > [ 34.001849] memcpy+0x20/0x60 > [ 34.002077] ismt_access.cold+0x374/0x214b > [ 34.003382] __i2c_smbus_xfer+0x44f/0xfb0 > [ 34.004007] i2c_smbus_xfer+0x10a/0x390 > [ 34.004291] i2cdev_ioctl_smbus+0x2c8/0x710 > [ 34.005196] i2cdev_ioctl+0x5ec/0x74c > > Fix this bug by checking the size of 'data->block[0]' first. > > Fixes: 13f35ac14cd0 ("i2c: Adding support for Intel iSMT SMBus 2.0 host controller") > Signed-off-by: Zheyu Ma <zheyuma97@gmail.com> Applied to for-next, thanks!
diff --git a/drivers/i2c/busses/i2c-ismt.c b/drivers/i2c/busses/i2c-ismt.c index 6078fa0c0d48..63120c41354c 100644 --- a/drivers/i2c/busses/i2c-ismt.c +++ b/drivers/i2c/busses/i2c-ismt.c @@ -509,6 +509,9 @@ static int ismt_access(struct i2c_adapter *adap, u16 addr, if (read_write == I2C_SMBUS_WRITE) { /* Block Write */ dev_dbg(dev, "I2C_SMBUS_BLOCK_DATA: WRITE\n"); + if (data->block[0] < 1 || data->block[0] > I2C_SMBUS_BLOCK_MAX) + return -EINVAL; + dma_size = data->block[0] + 1; dma_direction = DMA_TO_DEVICE; desc->wr_len_cmd = dma_size;
When the driver does not check the data from the user, the variable 'data->block[0]' may be very large to cause an out-of-bounds bug. The following log can reveal it: [ 33.995542] i2c i2c-1: ioctl, cmd=0x720, arg=0x7ffcb3dc3a20 [ 33.995978] ismt_smbus 0000:00:05.0: I2C_SMBUS_BLOCK_DATA: WRITE [ 33.996475] ================================================================== [ 33.996995] BUG: KASAN: out-of-bounds in ismt_access.cold+0x374/0x214b [ 33.997473] Read of size 18446744073709551615 at addr ffff88810efcfdb1 by task ismt_poc/485 [ 33.999450] Call Trace: [ 34.001849] memcpy+0x20/0x60 [ 34.002077] ismt_access.cold+0x374/0x214b [ 34.003382] __i2c_smbus_xfer+0x44f/0xfb0 [ 34.004007] i2c_smbus_xfer+0x10a/0x390 [ 34.004291] i2cdev_ioctl_smbus+0x2c8/0x710 [ 34.005196] i2cdev_ioctl+0x5ec/0x74c Fix this bug by checking the size of 'data->block[0]' first. Fixes: 13f35ac14cd0 ("i2c: Adding support for Intel iSMT SMBus 2.0 host controller") Signed-off-by: Zheyu Ma <zheyuma97@gmail.com> --- drivers/i2c/busses/i2c-ismt.c | 3 +++ 1 file changed, 3 insertions(+)