This is a note to let you know that I've just added the patch titled

kernel/relay.c: revert "kernel/relay.c: fix potential memory leak"

to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: kernel-relay.c-revert-kernel-relay.c-fix-potential-memory-leak.patch and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From a1be1f3931bfe0a42b46fef77a04593c2b136e7f Mon Sep 17 00:00:00 2001

From: Eric Biggers ebiggers@google.com Date: Tue, 6 Feb 2018 15:40:24 -0800 Subject: kernel/relay.c: revert "kernel/relay.c: fix potential memory leak"

From: Eric Biggers ebiggers@google.com

commit a1be1f3931bfe0a42b46fef77a04593c2b136e7f upstream.

This reverts commit ba62bafe942b ("kernel/relay.c: fix potential memory leak").

This commit introduced a double free bug, because 'chan' is already freed by the line:

kref_put(&chan->kref, relay_destroy_channel);

This bug was found by syzkaller, using the BLKTRACESETUP ioctl.

Link: http://lkml.kernel.org/r/20180127004759.101823-1-ebiggers3@gmail.com Fixes: ba62bafe942b ("kernel/relay.c: fix potential memory leak") Signed-off-by: Eric Biggers ebiggers@google.com Reported-by: syzbot syzkaller@googlegroups.com Reviewed-by: Andrew Morton akpm@linux-foundation.org Cc: Zhouyi Zhou yizhouzhou@ict.ac.cn Cc: Jens Axboe axboe@kernel.dk Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- kernel/relay.c | 1 - 1 file changed, 1 deletion(-)

--- a/kernel/relay.c +++ b/kernel/relay.c @@ -611,7 +611,6 @@ free_bufs:

kref_put(&chan->kref, relay_destroy_channel); mutex_unlock(&relay_channels_mutex); - kfree(chan); return NULL; } EXPORT_SYMBOL_GPL(relay_open);

Patches currently in stable-queue which might be from ebiggers@google.com are

queue-4.9/pipe-fix-off-by-one-error-when-checking-buffer-limits.patch queue-4.9/crypto-cryptd-pass-through-absence-of-setkey.patch queue-4.9/pipe-actually-allow-root-to-exceed-the-pipe-buffer-limits.patch queue-4.9/kernel-relay.c-revert-kernel-relay.c-fix-potential-memory-leak.patch queue-4.9/nfs-reject-request-for-id_legacy-key-without-auxdata.patch queue-4.9/crypto-poly1305-remove-setkey-method.patch queue-4.9/crypto-sha512-mb-initialize-pending-lengths-correctly.patch queue-4.9/crypto-hash-introduce-crypto_hash_alg_has_setkey.patch queue-4.9/crypto-mcryptd-pass-through-absence-of-setkey.patch