This is a note to let you know that I've just added the patch titled dell-laptop: Fix allocating & freeing SMI buffer page to the 4.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: dell-laptop-fix-allocating-freeing-smi-buffer-page.patch and it can be found in the queue-4.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From b8830a4e71b15d0364ac8e6c55301eea73f211da Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Pali=20Roh=C3=A1r?= <pali.rohar@xxxxxxxxx> Date: Tue, 23 Jun 2015 10:11:19 +0200 Subject: dell-laptop: Fix allocating & freeing SMI buffer page MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: =?UTF-8?q?Pali=20Roh=C3=A1r?= <pali.rohar@xxxxxxxxx> commit b8830a4e71b15d0364ac8e6c55301eea73f211da upstream. This commit fix kernel crash when probing for rfkill devices in dell-laptop driver failed. Function free_page() was incorrectly used on struct page * instead of virtual address of SMI buffer. This commit also simplify allocating page for SMI buffer by using __get_free_page() function instead of sequential call of functions alloc_page() and page_address(). Signed-off-by: Pali Rohár <pali.rohar@xxxxxxxxx> Acked-by: Michal Hocko <mhocko@xxxxxxx> Signed-off-by: Darren Hart <dvhart@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/platform/x86/dell-laptop.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) --- a/drivers/platform/x86/dell-laptop.c +++ b/drivers/platform/x86/dell-laptop.c @@ -305,7 +305,6 @@ static const struct dmi_system_id dell_q }; static struct calling_interface_buffer *buffer; -static struct page *bufferpage; static DEFINE_MUTEX(buffer_mutex); static int hwswitch_state; @@ -1896,12 +1895,11 @@ static int __init dell_init(void) * Allocate buffer below 4GB for SMI data--only 32-bit physical addr * is passed to SMI handler. */ - bufferpage = alloc_page(GFP_KERNEL | GFP_DMA32); - if (!bufferpage) { + buffer = (void *)__get_free_page(GFP_KERNEL | GFP_DMA32); + if (!buffer) { ret = -ENOMEM; goto fail_buffer; } - buffer = page_address(bufferpage); ret = dell_setup_rfkill(); @@ -1965,7 +1963,7 @@ fail_backlight: cancel_delayed_work_sync(&dell_rfkill_work); dell_cleanup_rfkill(); fail_rfkill: - free_page((unsigned long)bufferpage); + free_page((unsigned long)buffer); fail_buffer: platform_device_del(platform_device); fail_platform_device2: Patches currently in stable-queue which might be from pali.rohar@xxxxxxxxx are queue-4.1/dell-laptop-fix-allocating-freeing-smi-buffer-page.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html