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authorArtem Bityutskiy <artem.bityutskiy@linux.intel.com>2012-01-05 09:47:18 +0100
committerArtem Bityutskiy <artem.bityutskiy@linux.intel.com>2012-01-05 10:19:19 +0100
commite57e0d8e818512047fe379157c3f77f1b9fabffb (patch)
tree231ce6396d5c2b5ff40c6436bc713eb0c1e33ee7 /drivers/mtd/ubi
parentUBI: fix missing scrub when there is a bit-flip (diff)
downloadlinux-e57e0d8e818512047fe379157c3f77f1b9fabffb.tar.xz
linux-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>
Diffstat (limited to 'drivers/mtd/ubi')
-rw-r--r--drivers/mtd/ubi/wl.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c
index 277c429a138f..0696e36b0539 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 */