diff options
author | Zheyu Ma <zheyuma97@gmail.com> | 2022-08-04 15:41:23 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-08-21 16:16:13 +0300 |
commit | bd8269e57621e5b38cc0b4bd2fa02e85c9f2a441 (patch) | |
tree | 3cb0695c57b5c8bcd14a477020a5e02464200384 /drivers/video | |
parent | a9943942a501114d5ea1093329e3b04da597b085 (diff) | |
download | linux-bd8269e57621e5b38cc0b4bd2fa02e85c9f2a441.tar.xz |
video: fbdev: vt8623fb: Check the size of screen before memset_io()
[ Upstream commit ec0754c60217248fa77cc9005d66b2b55200ac06 ]
In the function vt8623fb_set_par(), the value of 'screen_size' is
calculated by the user input. If the user provides the improper value,
the value of 'screen_size' may larger than 'info->screen_size', which
may cause the following bug:
[ 583.339036] BUG: unable to handle page fault for address: ffffc90005000000
[ 583.339049] #PF: supervisor write access in kernel mode
[ 583.339052] #PF: error_code(0x0002) - not-present page
[ 583.339074] RIP: 0010:memset_orig+0x33/0xb0
[ 583.339110] Call Trace:
[ 583.339118] vt8623fb_set_par+0x11cd/0x21e0
[ 583.339146] fb_set_var+0x604/0xeb0
[ 583.339181] do_fb_ioctl+0x234/0x670
[ 583.339209] fb_ioctl+0xdd/0x130
Fix the this by checking the value of 'screen_size' before memset_io().
Fixes: 558b7bd86c32 ("vt8623fb: new framebuffer driver for VIA VT8623")
Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/video')
-rw-r--r-- | drivers/video/fbdev/vt8623fb.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/video/fbdev/vt8623fb.c b/drivers/video/fbdev/vt8623fb.c index 7a959e5ba90b..c274ec5e965c 100644 --- a/drivers/video/fbdev/vt8623fb.c +++ b/drivers/video/fbdev/vt8623fb.c @@ -504,6 +504,8 @@ static int vt8623fb_set_par(struct fb_info *info) (info->var.vmode & FB_VMODE_DOUBLE) ? 2 : 1, 1, 1, info->node); + if (screen_size > info->screen_size) + screen_size = info->screen_size; memset_io(info->screen_base, 0x00, screen_size); /* Device and screen back on */ |