This is a note to let you know that I've just added the patch titled
ext4: fix potential use after free in __ext4_journal_stop
to the 4.2-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ext4-fix-potential-use-after-free-in-__ext4_journal_stop.patch
and it can be found in the queue-4.2 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 6934da9238da947628be83635e365df41064b09b Mon Sep 17 00:00:00 2001
From: Lukas Czerner <[email protected]>
Date: Sat, 17 Oct 2015 22:57:06 -0400
Subject: ext4: fix potential use after free in __ext4_journal_stop
From: Lukas Czerner <[email protected]>
commit 6934da9238da947628be83635e365df41064b09b upstream.
There is a use-after-free possibility in __ext4_journal_stop() in the
case that we free the handle in the first jbd2_journal_stop() because
we're referencing handle->h_err afterwards. This was introduced in
9705acd63b125dee8b15c705216d7186daea4625 and it is wrong. Fix it by
storing the handle->h_err value beforehand and avoid referencing
potentially freed handle.
Fixes: 9705acd63b125dee8b15c705216d7186daea4625
Signed-off-by: Lukas Czerner <[email protected]>
Reviewed-by: Andreas Dilger <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
fs/ext4/ext4_jbd2.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
--- a/fs/ext4/ext4_jbd2.c
+++ b/fs/ext4/ext4_jbd2.c
@@ -88,13 +88,13 @@ int __ext4_journal_stop(const char *wher
return 0;
}
+ err = handle->h_err;
if (!handle->h_transaction) {
- err = jbd2_journal_stop(handle);
- return handle->h_err ? handle->h_err : err;
+ rc = jbd2_journal_stop(handle);
+ return err ? err : rc;
}
sb = handle->h_transaction->t_journal->j_private;
- err = handle->h_err;
rc = jbd2_journal_stop(handle);
if (!err)
Patches currently in stable-queue which might be from [email protected] are
queue-4.2/ext4-fix-potential-use-after-free-in-__ext4_journal_stop.patch
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