Well-spotted, thanks. I've just pushed this patch to the UBIFS git tree: From: Artem Bityutskiy Subject: [PATCH] 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 Cc: stable@kernel.org [v2.6.23+] Signed-off-by: Artem Bityutskiy --- 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 42c684c..036d213 100644 --- a/drivers/mtd/ubi/wl.c +++ b/drivers/mtd/ubi/wl.c @@ -1049,7 +1049,6 @@ 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) { @@ -1062,14 +1061,16 @@ 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 */ -- 1.7.7.3 -- Best Regards, Artem Bityutskiy