From: Wei Yongjun <weiyongjun1@xxxxxxxxxx>
KASAN report out-of-bounds read as follows:
BUG: KASAN: global-out-of-bounds in afe4404_read_raw+0x2ce/0x380 [afe4404]
Read of size 4 at addr ffffffffc00e4658 by task cat/278
CPU: 1 PID: 278 Comm: cat Tainted: G
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
Call Trace:
<TASK>
afe4404_read_raw+0x2ce/0x380 [afe4404]
iio_read_channel_info+0x249/0x2e0 [industrialio]
dev_attr_show+0x4b/0xa0 drivers/base/core.c:2195
sysfs_kf_seq_show+0x1ec/0x390 fs/sysfs/file.c:59
seq_read_iter+0x48d/0x10b0 fs/seq_file.c:230
kernfs_fop_read_iter+0x4e6/0x710 fs/kernfs/file.c:275
call_read_iter include/linux/fs.h:2153 [inline]
new_sync_read fs/read_write.c:389 [inline]
vfs_read+0x5f2/0x890 fs/read_write.c:470
ksys_read+0x106/0x220 fs/read_write.c:613
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x38/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x72/0xdc
RIP: 0033:0x7fe9c5ef6992
</TASK>
The buggy address belongs to the variable:
afe4404_channel_leds+0x18/0xffffffffffffe9c0 [afe4404]
This issue can be reproduce by singe command:
$ cat /sys/bus/i2c/devices/0-0058/iio\:device0/in_intensity6_raw
The array size of afe4404_channel_leds and afe4404_channel_offdacs
are less than channels, so access with chan->address cause OOB read
in afe4404_[read|write]_raw. Fix it by moving access before use them.
Fixes: b36e8257641a ("iio: health/afe440x: Use regmap fields")
Signed-off-by: Wei Yongjun <weiyongjun1@xxxxxxxxxx>
Acked-by: Andrew Davis <afd@xxxxxx>
---
v1 -> v2: also moved 'reg' to right before we use it
added Acked-by
---
drivers/iio/health/afe4404.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/iio/health/afe4404.c b/drivers/iio/health/afe4404.c
index 8fca787b2524..836da31b7e30 100644
--- a/drivers/iio/health/afe4404.c
+++ b/drivers/iio/health/afe4404.c
@@ -250,20 +250,20 @@ static int afe4404_read_raw(struct iio_dev *indio_dev,
int *val, int *val2, long mask)
{
struct afe4404_data *afe = iio_priv(indio_dev);
- unsigned int value_reg = afe4404_channel_values[chan->address];
- unsigned int led_field = afe4404_channel_leds[chan->address];
- unsigned int offdac_field = afe4404_channel_offdacs[chan->address];
+ unsigned int value_reg, led_field, offdac_field;
int ret;
switch (chan->type) {
case IIO_INTENSITY:
switch (mask) {
case IIO_CHAN_INFO_RAW:
+ value_reg = afe4404_channel_values[chan->address];
ret = regmap_read(afe->regmap, value_reg, val);
if (ret)
return ret;
return IIO_VAL_INT;
case IIO_CHAN_INFO_OFFSET:
+ offdac_field = afe4404_channel_offdacs[chan->address];
ret = regmap_field_read(afe->fields[offdac_field], val);
if (ret)
return ret;
@@ -273,6 +273,7 @@ static int afe4404_read_raw(struct iio_dev *indio_dev,
case IIO_CURRENT:
switch (mask) {
case IIO_CHAN_INFO_RAW:
+ led_field = afe4404_channel_leds[chan->address];
ret = regmap_field_read(afe->fields[led_field], val);
if (ret)
return ret;
@@ -295,19 +296,20 @@ static int afe4404_write_raw(struct iio_dev *indio_dev,
int val, int val2, long mask)
{
struct afe4404_data *afe = iio_priv(indio_dev);
- unsigned int led_field = afe4404_channel_leds[chan->address];
- unsigned int offdac_field = afe4404_channel_offdacs[chan->address];
+ unsigned int led_field, offdac_field;
switch (chan->type) {
case IIO_INTENSITY:
switch (mask) {
case IIO_CHAN_INFO_OFFSET:
+ offdac_field = afe4404_channel_offdacs[chan->address];
return regmap_field_write(afe->fields[offdac_field], val);
}
break;
case IIO_CURRENT:
switch (mask) {
case IIO_CHAN_INFO_RAW:
+ led_field = afe4404_channel_leds[chan->address];
return regmap_field_write(afe->fields[led_field], val);
}
break;
--
2.34.1
