| Message ID | 1420626762-30637-1-git-send-email-luis.henriques@canonical.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/crypto/af_alg.c b/crypto/af_alg.c index 6a3ad8011585..1de4beeb25f8 100644 --- a/crypto/af_alg.c +++ b/crypto/af_alg.c @@ -449,6 +449,9 @@ void af_alg_complete(struct crypto_async_request *req, int err) { struct af_alg_completion *completion = req->data; + if (err == -EINPROGRESS) + return; + completion->err = err; complete(&completion->completion); }
This is a note to let you know that I have just added a patch titled crypto: af_alg - fix backlog handling to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue This patch is scheduled to be released in version 3.16.7-ckt4. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.16.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From 7eefd05a0382c8572c052feb460cd35e9f7a17bc Mon Sep 17 00:00:00 2001 From: Rabin Vincent <rabin.vincent@axis.com> Date: Fri, 19 Dec 2014 13:36:08 +0100 Subject: crypto: af_alg - fix backlog handling commit 7e77bdebff5cb1e9876c561f69710b9ab8fa1f7e upstream. If a request is backlogged, it's complete() handler will get called twice: once with -EINPROGRESS, and once with the final error code. af_alg's complete handler, unlike other users, does not handle the -EINPROGRESS but instead always completes the completion that recvmsg() is waiting on. This can lead to a return to user space while the request is still pending in the driver. If userspace closes the sockets before the requests are handled by the driver, this will lead to use-after-frees (and potential crashes) in the kernel due to the tfm having been freed. The crashes can be easily reproduced (for example) by reducing the max queue length in cryptod.c and running the following (from http://www.chronox.de/libkcapi.html) on AES-NI capable hardware: $ while true; do kcapi -x 1 -e -c '__ecb-aes-aesni' \ -k 00000000000000000000000000000000 \ -p 00000000000000000000000000000000 >/dev/null & done Signed-off-by: Rabin Vincent <rabin.vincent@axis.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- crypto/af_alg.c | 3 +++ 1 file changed, 3 insertions(+) -- 2.1.4