| From | Ben Hutchings <> | Date | Tue, 05 May 2015 02:16:39 +0100 | Subject | [PATCH 3.2 141/221] iio: core: Fix double free. |
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3.2.69-rc1 review patch. If anyone has any objections, please let me know.
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From: Martin Fuzzey <mfuzzey@parkeon.com>
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 <mfuzzey@parkeon.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org> [bwh: Backported to 3.2: - Adjust filenames, context - Drop inapplicable change to iio_free_chan_devattr_list()] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> --- --- a/drivers/staging/iio/industrialio-core.c +++ b/drivers/staging/iio/industrialio-core.c @@ -711,6 +711,7 @@ static void iio_device_unregister_sysfs( 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( 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;
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