Re: [PATCH] video: fbdev: sm712fb: Fix crash in smtcfb_write()

Hi,

On Thu, Mar 3, 2022 at 12:49 AM Helge Deller deller@gmx.de wrote:

On 3/2/22 15:33, Zheyu Ma wrote:

...

When the sm712fb driver writes three bytes to the framebuffer, the driver will crash:

BUG: unable to handle page fault for address: ffffc90001ffffff
RIP: 0010:smtcfb_write+0x454/0x5b0
Call Trace:
 vfs_write+0x291/0xd60
 ? do_sys_openat2+0x27d/0x350
 ? __fget_light+0x54/0x340
 ksys_write+0xce/0x190
 do_syscall_64+0x43/0x90
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Fix it by removing the open-coded endianness fixup-code.

Signed-off-by: Zheyu Ma zheyuma97@gmail.com

Thanks... it's already in the fbdev git tree and queued up for v5.18... https://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdev.git/commi...

This patch fixes the crash in smtcfb_read(), but there is a similar bug in smtcfb_write(), and I mocked up your patch a wrote a new patch for it. So we should fix two bugs with two patches.

Regards, Zheyu Ma