This is a note to let you know that I've just added the patch titled iio: buffer: Fix memory leak in iio_buffers_alloc_sysfs_and_mask() to my char-misc git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git in the char-misc-testing branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will be merged to the char-misc-next branch sometime soon, after it passes testing, and the merge window is open. If you have any questions about this process, please let me know. >From 486a25084155bf633768c26f022201c051d6fd95 Mon Sep 17 00:00:00 2001 From: Yang Yingliang <yangyingliang@xxxxxxxxxx> Date: Mon, 18 Oct 2021 14:37:18 +0800 Subject: iio: buffer: Fix memory leak in iio_buffers_alloc_sysfs_and_mask() When 'iio_dev_opaque->buffer_ioctl_handler' alloc fails in iio_buffers_alloc_sysfs_and_mask(), the 'attrs' allocated in iio_buffer_register_legacy_sysfs_groups() will be leaked: unreferenced object 0xffff888108568d00 (size 128): comm "88", pid 2014, jiffies 4294963294 (age 26.920s) hex dump (first 32 bytes): 80 3e da 02 80 88 ff ff 00 3a da 02 80 88 ff ff .>.......:...... 00 35 da 02 80 88 ff ff 00 38 da 02 80 88 ff ff .5.......8...... backtrace: [<0000000095a9e51e>] __kmalloc+0x1a3/0x2f0 [<00000000faa3735e>] iio_buffers_alloc_sysfs_and_mask+0xfa3/0x1480 [industrialio] [<00000000a46384dc>] __iio_device_register+0x52e/0x1b40 [industrialio] [<00000000210af05e>] __devm_iio_device_register+0x22/0x80 [industrialio] [<00000000730d7b41>] adjd_s311_probe+0x195/0x200 [adjd_s311] [<00000000c0f70eb9>] i2c_device_probe+0xa07/0xbb0 The iio_buffer_register_legacy_sysfs_groups() is called in __iio_buffer_alloc_sysfs_and_mask(), so move the iio_buffer_unregister_legacy_sysfs_groups() into __iio_buffer_free_sysfs_and_mask(), then the memory will be freed. Reported-by: Hulk Robot <hulkci@xxxxxxxxxx> Fixes: d9a625744ed0 ("iio: core: merge buffer/ & scan_elements/ attributes") Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx> Link: https://lore.kernel.org/r/20211018063718.1971240-1-yangyingliang@xxxxxxxxxx Cc: <Stable@xxxxxxxxxxxxxxx> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> --- drivers/iio/industrialio-buffer.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c index 1c3972150ab4..2f98ba70e3d7 100644 --- a/drivers/iio/industrialio-buffer.c +++ b/drivers/iio/industrialio-buffer.c @@ -1587,8 +1587,12 @@ static int __iio_buffer_alloc_sysfs_and_mask(struct iio_buffer *buffer, return ret; } -static void __iio_buffer_free_sysfs_and_mask(struct iio_buffer *buffer) +static void __iio_buffer_free_sysfs_and_mask(struct iio_buffer *buffer, + struct iio_dev *indio_dev, + int index) { + if (index == 0) + iio_buffer_unregister_legacy_sysfs_groups(indio_dev); bitmap_free(buffer->scan_mask); kfree(buffer->buffer_group.name); kfree(buffer->buffer_group.attrs); @@ -1642,7 +1646,7 @@ int iio_buffers_alloc_sysfs_and_mask(struct iio_dev *indio_dev) error_unwind_sysfs_and_mask: for (; unwind_idx >= 0; unwind_idx--) { buffer = iio_dev_opaque->attached_buffers[unwind_idx]; - __iio_buffer_free_sysfs_and_mask(buffer); + __iio_buffer_free_sysfs_and_mask(buffer, indio_dev, unwind_idx); } return ret; } @@ -1659,11 +1663,9 @@ void iio_buffers_free_sysfs_and_mask(struct iio_dev *indio_dev) iio_device_ioctl_handler_unregister(iio_dev_opaque->buffer_ioctl_handler); kfree(iio_dev_opaque->buffer_ioctl_handler); - iio_buffer_unregister_legacy_sysfs_groups(indio_dev); - for (i = iio_dev_opaque->attached_buffers_cnt - 1; i >= 0; i--) { buffer = iio_dev_opaque->attached_buffers[i]; - __iio_buffer_free_sysfs_and_mask(buffer); + __iio_buffer_free_sysfs_and_mask(buffer, indio_dev, i); } } -- 2.33.1