commit 7e77bdebff 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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use this new function to make code more comprehensible, since we are
reinitialzing the completion, not initializing.
[akpm@linux-foundation.org: linux-next resyncs]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org> (personally at LCE13)
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change data type to fix warning:
crypto/af_alg.c:35: warning: initialization from incompatible pointer type
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch creates the backbone of the user-space interface for
the Crypto API, through a new socket family AF_ALG.
Each session corresponds to one or more connections obtained from
that socket. The number depends on the number of inputs/outputs
of that particular type of operation. For most types there will
be a s ingle connection/file descriptor that is used for both input
and output. AEAD is one of the few that require two inputs.
Each algorithm type will provide its own implementation that plugs
into af_alg. They're keyed using a string such as "skcipher" or
"hash".
IOW this patch only contains the boring bits that is required
to hold everything together.
Thakns to Miloslav Trmac for reviewing this and contributing
fixes and improvements.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: David S. Miller <davem@davemloft.net>
Tested-by: Martin Willi <martin@strongswan.org>
