path: root/drivers/mtd/ubi/kapi.c
diff options
authorJesper Juhl <jesper.juhl@gmail.com>2007-08-04 01:25:26 +0200
committerArtem Bityutskiy <Artem.Bityutskiy@nokia.com>2007-10-14 13:10:20 +0300
commit0169b49d52400a6035cd0f2ccd08bcba061a1a9b (patch)
tree534643ffe146db43ece0ce2476c2da919408bce5 /drivers/mtd/ubi/kapi.c
parent8d2d4011f1398d984819c65043abb559c451a3c8 (diff)
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>
Diffstat (limited to 'drivers/mtd/ubi/kapi.c')
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/mtd/ubi/kapi.c b/drivers/mtd/ubi/kapi.c
index 4a458e83e4e..03c774f4154 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;