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| author | Tomi Valkeinen <tomi.valkeinen@ti.com> | 2018-09-26 18:11:22 +0200 |
|---|---|---|
| committer | Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> | 2018-09-26 18:11:22 +0200 |
| commit | 1bafcbf59fed92af58955024452f45430d3898c5 (patch) | |
| tree | ee45bb8b910f281248c4528ddc290e75e4253241 /drivers/video | |
| parent | d85536cde91fcfed6fb8d983783bd2b92c843939 (diff) | |
| download | linux-1bafcbf59fed92af58955024452f45430d3898c5.tar.bz2 | |
fbdev/omapfb: fix omapfb_memory_read infoleak
OMAPFB_MEMORY_READ ioctl reads pixels from the LCD's memory and copies
them to a userspace buffer. The code has two issues:
- The user provided width and height could be large enough to overflow
the calculations
- The copy_to_user() can copy uninitialized memory to the userspace,
which might contain sensitive kernel information.
Fix these by limiting the width & height parameters, and only copying
the amount of data that we actually received from the LCD.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Reported-by: Jann Horn <jannh@google.com>
Cc: stable@vger.kernel.org
Cc: security@kernel.org
Cc: Will Deacon <will.deacon@arm.com>
Cc: Jann Horn <jannh@google.com>
Cc: Tony Lindgren <tony@atomide.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Diffstat (limited to 'drivers/video')
| -rw-r--r-- | drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c b/drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c index ef69273074ba..a3edb20ea4c3 100644 --- a/drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c +++ b/drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c @@ -496,6 +496,9 @@ static int omapfb_memory_read(struct fb_info *fbi, if (!access_ok(VERIFY_WRITE, mr->buffer, mr->buffer_size)) return -EFAULT; + if (mr->w > 4096 || mr->h > 4096) + return -EINVAL; + if (mr->w * mr->h * 3 > mr->buffer_size) return -EINVAL; @@ -509,7 +512,7 @@ static int omapfb_memory_read(struct fb_info *fbi, mr->x, mr->y, mr->w, mr->h); if (r > 0) { - if (copy_to_user(mr->buffer, buf, mr->buffer_size)) + if (copy_to_user(mr->buffer, buf, r)) r = -EFAULT; } |