iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

media: v4l2-tpg: fix kernel oops when enabling HFLIP and OSD

Browse Source 
commit 250854eed5d45a73d81e4137dfd85180af6f2ec3 upstream.

When the OSD is on (i.e. vivid displays text on top of the test pattern), and
you enable hflip, then the driver crashes.

The cause turned out to be a division of a negative number by an unsigned value.
You expect that -8 / 2U would be -4, but in reality it is 2147483644 :-(

Fixes: 3e14e7a82c1ef ("vivid-tpg: add hor/vert downsampling support to tpg_gen_text")

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reported-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: <stable@vger.kernel.org>      # for v4.1 and up
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Hans Verkuil 2018-10-08 15:08:27 -04:00 committed by Greg Kroah-Hartman
parent e7f6b41ad2
commit fdff1cf089
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/media/common/v4l2-tpg/v4l2-tpg-core.c
View File

@ -1765,7 +1765,7 @@ typedef struct { u16 __; u8 _; } __packed x24;
pos[7] = (chr & (0x01 << 0) ? fg : bg); \
} \
\
pos += (tpg->hflip ? -8 : 8) / hdiv; \
pos += (tpg->hflip ? -8 : 8) / (int)hdiv; \
} \
} \
} while (0)