diff options
| author | Zheyu Ma <zheyuma97@gmail.com> | 2022-03-02 17:33:11 +0300 |
|---|---|---|
| committer | Helge Deller <deller@gmx.de> | 2022-03-03 13:13:40 +0300 |
| commit | 4f01d09b2bbfbcb47b3eb305560a7f4857a32260 (patch) | |
| tree | c136d3112f10c039e0488f487beab4ddd662f5ed /drivers/video | |
| parent | 961e366c85314c31a367fcf32fa944be64167d75 (diff) | |
| download | linux-4f01d09b2bbfbcb47b3eb305560a7f4857a32260.tar.xz | |
video: fbdev: sm712fb: Fix crash in smtcfb_write()
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>
Signed-off-by: Helge Deller <deller@gmx.de>
Diffstat (limited to 'drivers/video')
| -rw-r--r-- | drivers/video/fbdev/sm712fb.c | 21 |
1 files changed, 4 insertions, 17 deletions
diff --git a/drivers/video/fbdev/sm712fb.c b/drivers/video/fbdev/sm712fb.c index b60a2730f0a8..092a1caa1208 100644 --- a/drivers/video/fbdev/sm712fb.c +++ b/drivers/video/fbdev/sm712fb.c @@ -1119,7 +1119,7 @@ static ssize_t smtcfb_write(struct fb_info *info, const char __user *buf, count = total_size - p; } - buffer = kmalloc((count > PAGE_SIZE) ? PAGE_SIZE : count, GFP_KERNEL); + buffer = kmalloc(PAGE_SIZE, GFP_KERNEL); if (!buffer) return -ENOMEM; @@ -1137,24 +1137,11 @@ static ssize_t smtcfb_write(struct fb_info *info, const char __user *buf, break; } - for (i = c >> 2; i--;) { - fb_writel(big_swap(*src), dst++); + for (i = (c + 3) >> 2; i--;) { + fb_writel(big_swap(*src), dst); + dst++; src++; } - if (c & 3) { - u8 *src8 = (u8 *)src; - u8 __iomem *dst8 = (u8 __iomem *)dst; - - for (i = c & 3; i--;) { - if (i & 1) { - fb_writeb(*src8++, ++dst8); - } else { - fb_writeb(*src8++, --dst8); - dst8 += 2; - } - } - dst = (u32 __iomem *)dst8; - } *ppos += c; buf += c; |