[PATCH 5.14 620/849] iio: buffer: Fix double-free in iio_buffers_alloc_sysfs_and_mask()

Greg Kroah-Hartman
2021-11-15T23:12:03Z

From: Yang Yingliang <yangyingliang@huawei.com>

[ Upstream commit 09776d9374e635b1580b3736c19b95b788fbaa85 ]

When __iio_buffer_alloc_sysfs_and_mask() failed, 'unwind_idx' should be
set to 'i - 1' to prevent double-free when cleanup resources.

BUG: KASAN: double-free or invalid-free in __iio_buffer_free_sysfs_and_mask+0x32/0xb0 [industrialio]
Call Trace:
kfree+0x117/0x4c0
__iio_buffer_free_sysfs_and_mask+0x32/0xb0 [industrialio]
iio_buffers_alloc_sysfs_and_mask+0x60d/0x1570 [industrialio]
__iio_device_register+0x483/0x1a30 [industrialio]
ina2xx_probe+0x625/0x980 [ina2xx_adc]

Reported-by: Hulk Robot <hulkci@huawei.com>
Fixes: ee708e6baacd ("iio: buffer: introduce support for attaching more IIO buffers")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20211013094923.2473-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/iio/industrialio-buffer.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index 2801f3a650760..1dfd10831f379 100644
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -1623,7 +1623,7 @@ int iio_buffers_alloc_sysfs_and_mask(struct iio_dev *indio_dev)
buffer = iio_dev_opaque->attached_buffers[i];
ret = __iio_buffer_alloc_sysfs_and_mask(buffer, indio_dev, i);
if (ret) {
- unwind_idx = i;
+ unwind_idx = i - 1;
goto error_unwind_sysfs_and_mask;
}
}
--
2.33.0