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author | Artem Bityutskiy <artem.bityutskiy@linux.intel.com> | 2012-01-05 10:47:18 +0200 |
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committer | Artem Bityutskiy <artem.bityutskiy@linux.intel.com> | 2012-01-05 11:19:19 +0200 |
commit | e57e0d8e818512047fe379157c3f77f1b9fabffb (patch) | |
tree | 231ce6396d5c2b5ff40c6436bc713eb0c1e33ee7 | |
parent | e801e128b2200c40a0ec236cf2330b2586b6e05a (diff) | |
download | linux-3.10-e57e0d8e818512047fe379157c3f77f1b9fabffb.tar.gz linux-3.10-e57e0d8e818512047fe379157c3f77f1b9fabffb.tar.bz2 linux-3.10-e57e0d8e818512047fe379157c3f77f1b9fabffb.zip |
UBI: fix use-after-free on error path
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>
Cc: stable@kernel.org [v2.6.23+]
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
-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 277c429a138..0696e36b053 100644 --- a/drivers/mtd/ubi/wl.c +++ b/drivers/mtd/ubi/wl.c @@ -1052,7 +1052,6 @@ 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) { @@ -1065,14 +1064,16 @@ 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 */ |