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| author | Jesper Juhl <jesper.juhl@gmail.com> | 2007-08-04 01:25:26 +0200 |
|---|---|---|
| committer | Artem Bityutskiy <Artem.Bityutskiy@nokia.com> | 2007-10-14 13:10:20 +0300 |
| commit | 0169b49d52400a6035cd0f2ccd08bcba061a1a9b (patch) | |
| tree | 534643ffe146db43ece0ce2476c2da919408bce5 | |
| parent | 8d2d4011f1398d984819c65043abb559c451a3c8 (diff) | |
| download | linux-0169b49d52400a6035cd0f2ccd08bcba061a1a9b.tar.gz linux-0169b49d52400a6035cd0f2ccd08bcba061a1a9b.tar.bz2 linux-0169b49d52400a6035cd0f2ccd08bcba061a1a9b.zip | |
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>
| -rw-r--r-- | drivers/mtd/ubi/kapi.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/mtd/ubi/kapi.c b/drivers/mtd/ubi/kapi.c index 4a458e83e4e9..03c774f41549 100644 --- a/drivers/mtd/ubi/kapi.c +++ b/drivers/mtd/ubi/kapi.c @@ -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; |