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authorMauro Carvalho Chehab <mchehab@redhat.com>2008-11-13 17:03:28 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2008-11-14 14:24:45 -0200
commit494264379d186bf806613d27aafb7d88d42f4212 (patch)
tree681aeb1444d7e1b2d994d5045644a0c8ec44e342
parent81cb5c4f7fbe6971d9c61401bc47193290fd59b7 (diff)
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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 <mchehab@redhat.com>
-rw-r--r--drivers/media/video/tvaudio.c30
1 files changed, 27 insertions, 3 deletions
diff --git a/drivers/media/video/tvaudio.c b/drivers/media/video/tvaudio.c
index 5ec369d54e6e..55b39b9a33d9 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]);