From 073bfbba54f94f1a9d3f20d5e07d830efe8f8f3a Mon Sep 17 00:00:00 2001 From: Martin Fuzzey Date: Thu, 19 Feb 2015 15:17:44 +0100 Subject: [PATCH] iio: core: Fix double free. commit c1b03ab5e886760bdd38c9c7a27af149046ffe01 upstream. When an error occurred during event registration memory was freed twice resulting in kernel memory corruption and a crash in unrelated code. The problem was caused by iio_device_unregister_eventset() iio_device_unregister_sysfs() being called twice, once on the error path and then again via iio_dev_release(). Fix this by making these two functions idempotent so they may be called multiple times. The problem was observed before applying 78b33216 iio:core: Handle error when mask type is not separate Signed-off-by: Martin Fuzzey Signed-off-by: Jonathan Cameron [bwh: Backported to 3.2: - Adjust filenames, context - Drop inapplicable change to iio_free_chan_devattr_list()] Signed-off-by: Ben Hutchings --- drivers/staging/iio/industrialio-core.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/staging/iio/industrialio-core.c b/drivers/staging/iio/industrialio-core.c index aec9311b108c..f0abf29f261a 100644 --- a/drivers/staging/iio/industrialio-core.c +++ b/drivers/staging/iio/industrialio-core.c @@ -711,6 +711,7 @@ static void iio_device_unregister_sysfs(struct iio_dev *indio_dev) iio_device_remove_and_free_read_attr(indio_dev, p); } kfree(indio_dev->chan_attr_group.attrs); + indio_dev->chan_attr_group.attrs = NULL; } static const char * const iio_ev_type_text[] = { @@ -986,6 +987,7 @@ static int iio_device_register_eventset(struct iio_dev *indio_dev) error_free_setup_event_lines: __iio_remove_event_config_attrs(indio_dev); kfree(indio_dev->event_interface); + indio_dev->event_interface = NULL; error_ret: return ret; -- 2.39.2