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| author | Zheyu Ma <zheyuma97@gmail.com> | 2022-03-02 22:33:11 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-04-20 09:06:40 +0200 |
| commit | fb791514acf9070225eed46e1ccbb0aa7aae5da5 (patch) | |
| tree | d758078881ead0ff3fecccb50b8d6afe4fc817e8 /drivers/video | |
| parent | 734ff1117d5f7d7ca41bda5666366bb95fbc062b (diff) | |
| download | linux-stable-fb791514acf9070225eed46e1ccbb0aa7aae5da5.tar.gz linux-stable-fb791514acf9070225eed46e1ccbb0aa7aae5da5.tar.bz2 linux-stable-fb791514acf9070225eed46e1ccbb0aa7aae5da5.zip | |
video: fbdev: sm712fb: Fix crash in smtcfb_write()
[ Upstream commit 4f01d09b2bbfbcb47b3eb305560a7f4857a32260 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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 841fd0c7ce9b..620f3152213a 100644 --- a/drivers/video/fbdev/sm712fb.c +++ b/drivers/video/fbdev/sm712fb.c @@ -1118,7 +1118,7 @@ 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; @@ -1136,24 +1136,11 @@ 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; |