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| author | Artem Bityutskiy <artem.bityutskiy@linux.intel.com> | 2012-01-05 10:47:18 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2012-01-25 13:53:19 -0800 |
| commit | 78771467f80f450962913dfabe495e4fb517f9b2 (patch) | |
| tree | 7f0149af06b64f93bd6af1b1ed958462f63840e1 | |
| parent | da41cc6e4d68e5d2c4d15353d229e95bee2b529d (diff) | |
| download | lwn-78771467f80f450962913dfabe495e4fb517f9b2.tar.gz lwn-78771467f80f450962913dfabe495e4fb517f9b2.zip | |
UBI: fix use-after-free on error path
commit e57e0d8e818512047fe379157c3f77f1b9fabffb upstream.
When we fail to erase a PEB, we free the corresponding erase entry object,
but then re-schedule this object if the error code was something like -EAGAIN.
Obviously, it is a bug to use the object after we have freed it.
Reported-by: Emese Revfy <re.emese@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | drivers/mtd/ubi/wl.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c index 600c7229d5cf..ca42c00ec85e 100644 --- a/drivers/mtd/ubi/wl.c +++ b/drivers/mtd/ubi/wl.c @@ -1036,7 +1036,6 @@ static int erase_worker(struct ubi_device *ubi, struct ubi_work *wl_wrk, ubi_err("failed to erase PEB %d, error %d", pnum, err); kfree(wl_wrk); - kmem_cache_free(ubi_wl_entry_slab, e); if (err == -EINTR || err == -ENOMEM || err == -EAGAIN || err == -EBUSY) { @@ -1049,14 +1048,16 @@ static int erase_worker(struct ubi_device *ubi, struct ubi_work *wl_wrk, goto out_ro; } return err; - } else if (err != -EIO) { + } + + kmem_cache_free(ubi_wl_entry_slab, e); + if (err != -EIO) /* * If this is not %-EIO, we have no idea what to do. Scheduling * this physical eraseblock for erasure again would cause * errors again and again. Well, lets switch to R/O mode. */ goto out_ro; - } /* It is %-EIO, the PEB went bad */ |