Commit 0169b49d authored Aug 04, 2007 by Jesper Juhl Committed by Artem Bityutskiy Oct 14, 2007

UBI: don't use array index before testing if it is negative



I can't find anything guaranteeing that 'ubi_num' cannot be <0 in
drivers/mtd/ubi/kapi.c::ubi_open_volume(), and in fact the code
even tests for that and errors out if so. Unfortunately the test
for "ubi_num < 0" happens after we've already used 'ubi_num' as
an array index - bad thing to do if it is negative.
This patch moves the test earlier in the function and then moves
the indexing using that variable after the check. A bit safer :-)

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

parent 8d2d4011

drivers/mtd/ubi/kapi.c

+7 −2

Original line number	Diff line number	Diff line
		@@ -99,16 +99,21 @@ struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode)
		{
		int err;
		struct ubi_volume_desc *desc;
		struct ubi_device *ubi = ubi_devices[ubi_num];
		struct ubi_device *ubi;
		struct ubi_volume *vol;

		dbg_msg("open device %d volume %d, mode %d", ubi_num, vol_id, mode);

		err = -ENODEV;
		if (ubi_num < 0)
		return ERR_PTR(err);

		ubi = ubi_devices[ubi_num];

		if (!try_module_get(THIS_MODULE))
		return ERR_PTR(err);

		if (ubi_num < 0 \|\| ubi_num >= UBI_MAX_DEVICES \|\| !ubi)
		if (ubi_num >= UBI_MAX_DEVICES \|\| !ubi)
		goto out_put;

		err = -EINVAL;

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