From 494264379d186bf806613d27aafb7d88d42f4212 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Thu, 13 Nov 2008 17:03:28 -0300 Subject: [PATCH] V4L/DVB (9621): Avoid writing outside shadow.bytes[] array There were no check about the limits of shadow.bytes array. This offers a risk of writing values outside the limits, overriding other data areas. Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/tvaudio.c | 30 +++++++++++++++++++++++++++--- 1 file changed, 27 insertions(+), 3 deletions(-) diff --git a/drivers/media/video/tvaudio.c b/drivers/media/video/tvaudio.c index 5ec369d54e6..55b39b9a33d 100644 --- a/drivers/media/video/tvaudio.c +++ b/drivers/media/video/tvaudio.c @@ -154,7 +154,7 @@ static int chip_write(struct CHIPSTATE *chip, int subaddr, int val) { unsigned char buffer[2]; - if (-1 == subaddr) { + if (subaddr < 0) { v4l_dbg(1, debug, chip->c, "%s: chip_write: 0x%x\n", chip->c->name, val); chip->shadow.bytes[1] = val; @@ -165,6 +165,13 @@ static int chip_write(struct CHIPSTATE *chip, int subaddr, int val) return -1; } } else { + if (subaddr + 1 >= ARRAY_SIZE(chip->shadow.bytes)) { + v4l_info(chip->c, + "Tried to access a non-existent register: %d\n", + subaddr); + return -EINVAL; + } + v4l_dbg(1, debug, chip->c, "%s: chip_write: reg%d=0x%x\n", chip->c->name, subaddr, val); chip->shadow.bytes[subaddr+1] = val; @@ -179,12 +186,20 @@ static int chip_write(struct CHIPSTATE *chip, int subaddr, int val) return 0; } -static int chip_write_masked(struct CHIPSTATE *chip, int subaddr, int val, int mask) +static int chip_write_masked(struct CHIPSTATE *chip, + int subaddr, int val, int mask) { if (mask != 0) { - if (-1 == subaddr) { + if (subaddr < 0) { val = (chip->shadow.bytes[1] & ~mask) | (val & mask); } else { + if (subaddr + 1 >= ARRAY_SIZE(chip->shadow.bytes)) { + v4l_info(chip->c, + "Tried to access a non-existent register: %d\n", + subaddr); + return -EINVAL; + } + val = (chip->shadow.bytes[subaddr+1] & ~mask) | (val & mask); } } @@ -230,6 +245,15 @@ static int chip_cmd(struct CHIPSTATE *chip, char *name, audiocmd *cmd) if (0 == cmd->count) return 0; + if (cmd->count + cmd->bytes[0] - 1 >= ARRAY_SIZE(chip->shadow.bytes)) { + v4l_info(chip->c, + "Tried to access a non-existent register range: %d to %d\n", + cmd->bytes[0] + 1, cmd->bytes[0] + cmd->count - 1); + return -EINVAL; + } + + /* FIXME: it seems that the shadow bytes are wrong bellow !*/ + /* update our shadow register set; print bytes if (debug > 0) */ v4l_dbg(1, debug, chip->c, "%s: chip_cmd(%s): reg=%d, data:", chip->c->name, name,cmd->bytes[0]); -- 2.41.1