From: Wei Yongjun <weiyongjun1@xxxxxxxxxx>
KASAN report out-of-bounds read as follows:
BUG: KASAN: global-out-of-bounds in afe4403_read_raw+0x42e/0x4c0 [afe4403]
Read of size 4 at addr ffffffffc02ac638 by task cat/279
CPU: 2 PID: 279 Comm: cat Tainted: G N
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
Call Trace:
<TASK>
afe4403_read_raw+0x42e/0x4c0 [afe4403 141d77410f5466ef049ee2376f5136b77a168de0]
iio_read_channel_info+0x249/0x2e0 [industrialio d0627df60a92bbb9630e68c3e2f98d20dac889ef]
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: 0033:0x7fd8611cf992
</TASK>
The buggy address belongs to the variable:
afe4403_channel_leds+0x18/0xffffffffffffe9e0 [afe4403]
This issue can be reproduced by singe command:
$ cat /sys/bus/spi/devices/spi0.0/iio\:device0/in_intensity6_raw
The array size of afe4403_channel_leds is less than channels, so access
with chan->address cause OOB read in afe4403_read_raw. Fix it by moving
access before use it.
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
---
drivers/iio/health/afe4403.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/iio/health/afe4403.c b/drivers/iio/health/afe4403.c
index 3bb4028c5d74..df3bc5c3d378 100644
--- a/drivers/iio/health/afe4403.c
+++ b/drivers/iio/health/afe4403.c
@@ -245,14 +245,14 @@ static int afe4403_read_raw(struct iio_dev *indio_dev,
int *val, int *val2, long mask)
{
struct afe4403_data *afe = iio_priv(indio_dev);
- unsigned int reg = afe4403_channel_values[chan->address];
- unsigned int field = afe4403_channel_leds[chan->address];
+ unsigned int reg, field;
int ret;
switch (chan->type) {
case IIO_INTENSITY:
switch (mask) {
case IIO_CHAN_INFO_RAW:
+ reg = afe4403_channel_values[chan->address];
ret = afe4403_read(afe, reg, val);
if (ret)
return ret;
@@ -262,6 +262,7 @@ static int afe4403_read_raw(struct iio_dev *indio_dev,
case IIO_CURRENT:
switch (mask) {
case IIO_CHAN_INFO_RAW:
+ field = afe4403_channel_leds[chan->address];
ret = regmap_field_read(afe->fields[field], val);
if (ret)
return ret;
--
2.34.1
