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author | Dan Carpenter <dan.carpenter@oracle.com> | 2019-08-21 10:24:56 +0300 |
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committer | Noralf Trønnes <noralf@tronnes.org> | 2019-08-26 14:50:55 +0200 |
commit | d72cf01f410aa09868d98b672f3f92328c96b32d (patch) | |
tree | a1e21abcd34b9e5d5a47d090cbb9314e303557ed /drivers/gpu/drm/mcde | |
parent | 6dbe0c4b0fc0646442b2b1580d022404e582fd7b (diff) | |
download | linux-d72cf01f410aa09868d98b672f3f92328c96b32d.tar.bz2 |
drm/mipi-dbi: fix a loop in debugfs code
This code will likely crash if we try to do a zero byte write. The code
looks like this:
/* strip trailing whitespace */
for (i = count - 1; i > 0; i--)
if (isspace(buf[i]))
...
We're writing zero bytes so count = 0. You would think that "count - 1"
would be negative one, but because "i" is unsigned it is a large
positive numer instead. The "i > 0" condition is true and the "buf[i]"
access will be out of bounds.
The fix is to make "i" signed and now everything works as expected. The
upper bound of "count" is capped in __kernel_write() at MAX_RW_COUNT so
we don't have to worry about it being higher than INT_MAX.
Fixes: 02dd95fe3169 ("drm/tinydrm: Add MIPI DBI support")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
[noralf: Adjust title]
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190821072456.GJ26957@mwanda
Diffstat (limited to 'drivers/gpu/drm/mcde')
0 files changed, 0 insertions, 0 deletions