linux.git/crypto/algif_aead.c, branch v4.14.232

crypto: algif_aead - Do not set MAY_BACKLOG on the async path

2020-10-29T08:07:00+00:00

commit cbdad1f246dd98e6c9c32a6e5212337f542aa7e0 upstream.

The async path cannot use MAY_BACKLOG because it is not meant to
block, which is what MAY_BACKLOG does.  On the other hand, both
the sync and async paths can make use of MAY_SLEEP.

Fixes: 83094e5e9e49 ("crypto: af_alg - add async support to...")
Cc: 
Signed-off-by: Herbert Xu 
Signed-off-by: Greg Kroah-Hartman

crypto: af_alg - fix use-after-free in af_alg_accept() due to bh_lock_sock()

2020-07-09T07:36:30+00:00

commit 34c86f4c4a7be3b3e35aa48bd18299d4c756064d upstream.

The locking in af_alg_release_parent is broken as the BH socket
lock can only be taken if there is a code-path to handle the case
where the lock is owned by process-context.  Instead of adding
such handling, we can fix this by changing the ref counts to
atomic_t.

This patch also modifies the main refcnt to include both normal
and nokey sockets.  This way we don't have to fudge the nokey
ref count when a socket changes from nokey to normal.

Credits go to Mauricio Faria de Oliveira who diagnosed this bug
and sent a patch for it:

https://lore.kernel.org/linux-crypto/20200605161657.535043-1-mfo@canonical.com/

Reported-by: Brian Moyles 
Reported-by: Mauricio Faria de Oliveira 
Fixes: 37f96694cf73 ("crypto: af_alg - Use bh_lock_sock in...")
Cc: 
Signed-off-by: Herbert Xu 
Signed-off-by: Greg Kroah-Hartman

crypto: af_alg - Fix race around ctx->rcvused by making it atomic_t

2018-03-03T09:24:29+00:00

[ Upstream commit af955bf15d2c27496b0269b1f05c26f758c68314 ]

This variable was increased and decreased without any protection.
Result was an occasional misscount and negative wrap around resulting
in false resource allocation failures.

Fixes: 7d2c3f54e6f6 ("crypto: af_alg - remove locking in async callback")
Signed-off-by: Jonathan Cameron 
Reviewed-by: Stephan Mueller 
Signed-off-by: Herbert Xu 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

crypto: af_alg - fix race accessing cipher request

2017-12-29T16:53:46+00:00

commit d53c5135792319e095bb126bc43b2ee98586f7fe upstream.

When invoking an asynchronous cipher operation, the invocation of the
callback may be performed before the subsequent operations in the
initial code path are invoked. The callback deletes the cipher request
data structure which implies that after the invocation of the
asynchronous cipher operation, this data structure must not be accessed
any more.

The setting of the return code size with the request data structure must
therefore be moved before the invocation of the asynchronous cipher
operation.

Fixes: e870456d8e7c ("crypto: algif_skcipher - overhaul memory management")
Fixes: d887c52d6ae4 ("crypto: algif_aead - overhaul memory management")
Reported-by: syzbot 
Signed-off-by: Stephan Mueller 
Acked-by: Jonathan Cameron 
Signed-off-by: Herbert Xu 
Signed-off-by: Greg Kroah-Hartman

crypto: af_alg - wait for data at beginning of recvmsg

2017-12-29T16:53:46+00:00

commit 11edb555966ed2c66c533d17c604f9d7e580a829 upstream.

The wait for data is a non-atomic operation that can sleep and therefore
potentially release the socket lock. The release of the socket lock
allows another thread to modify the context data structure. The waiting
operation for new data therefore must be called at the beginning of
recvmsg. This prevents a race condition where checks of the members of
the context data structure are performed by recvmsg while there is a
potential for modification of these values.

Fixes: e870456d8e7c ("crypto: algif_skcipher - overhaul memory management")
Fixes: d887c52d6ae4 ("crypto: algif_aead - overhaul memory management")
Reported-by: syzbot 
Signed-off-by: Stephan Mueller 
Signed-off-by: Herbert Xu 
Signed-off-by: Greg Kroah-Hartman

crypto: algif_aead - fix reference counting of null skcipher

2017-12-20T09:10:16+00:00

commit b32a7dc8aef1882fbf983eb354837488cc9d54dc upstream.

In the AEAD interface for AF_ALG, the reference to the "null skcipher"
held by each tfm was being dropped in the wrong place -- when each
af_alg_ctx was freed instead of when the aead_tfm was freed.  As
discovered by syzkaller, a specially crafted program could use this to
cause the null skcipher to be freed while it is still in use.

Fix it by dropping the reference in the right place.

Fixes: 72548b093ee3 ("crypto: algif_aead - copy AAD from src to dst")
Reported-by: syzbot 
Signed-off-by: Eric Biggers 
Reviewed-by: Stephan Mueller 
Signed-off-by: Herbert Xu 
Signed-off-by: Greg Kroah-Hartman

crypto: af_alg - remove locking in async callback

2017-12-05T10:26:30+00:00

commit 7d2c3f54e6f646887d019faa45f35d6fe9fe82ce upstream.

The code paths protected by the socket-lock do not use or modify the
socket in a non-atomic fashion. The actions pertaining the socket do not
even need to be handled as an atomic operation. Thus, the socket-lock
can be safely ignored.

This fixes a bug regarding scheduling in atomic as the callback function
may be invoked in interrupt context.

In addition, the sock_hold is moved before the AIO encrypt/decrypt
operation to ensure that the socket is always present. This avoids a
tiny race window where the socket is unprotected and yet used by the AIO
operation.

Finally, the release of resources for a crypto operation is moved into a
common function of af_alg_free_resources.

Fixes: e870456d8e7c8 ("crypto: algif_skcipher - overhaul memory management")
Fixes: d887c52d6ae43 ("crypto: algif_aead - overhaul memory management")
Reported-by: Romain Izard 
Signed-off-by: Stephan Mueller 
Tested-by: Romain Izard 
Signed-off-by: Herbert Xu 
Signed-off-by: Greg Kroah-Hartman

crypto: algif_aead - skip SGL entries with NULL page

2017-12-05T10:26:30+00:00

commit 8e1fa89aa8bc2870009b4486644e4a58f2e2a4f5 upstream.

The TX SGL may contain SGL entries that are assigned a NULL page. This
may happen if a multi-stage AIO operation is performed where the data
for each stage is pointed to by one SGL entry. Upon completion of that
stage, af_alg_pull_tsgl will assign NULL to the SGL entry.

The NULL cipher used to copy the AAD from TX SGL to the destination
buffer, however, cannot handle the case where the SGL starts with an SGL
entry having a NULL page. Thus, the code needs to advance the start
pointer into the SGL to the first non-NULL entry.

This fixes a crash visible on Intel x86 32 bit using the libkcapi test
suite.

Fixes: 72548b093ee38 ("crypto: algif_aead - copy AAD from src to dst")
Signed-off-by: Stephan Mueller 
Signed-off-by: Herbert Xu 
Signed-off-by: Greg Kroah-Hartman

crypto: algif_aead - fix comment regarding memory layout

2017-08-22T06:54:50+00:00

Signed-off-by: Stephan Mueller 
Signed-off-by: Herbert Xu

crypto: af_alg - consolidation of duplicate code

2017-08-09T12:18:32+00:00

Consolidate following data structures:

skcipher_async_req, aead_async_req -> af_alg_async_req
skcipher_rsgl, aead_rsql -> af_alg_rsgl
skcipher_tsgl, aead_tsql -> af_alg_tsgl
skcipher_ctx, aead_ctx -> af_alg_ctx

Consolidate following functions:

skcipher_sndbuf, aead_sndbuf -> af_alg_sndbuf
skcipher_writable, aead_writable -> af_alg_writable
skcipher_rcvbuf, aead_rcvbuf -> af_alg_rcvbuf
skcipher_readable, aead_readable -> af_alg_readable
aead_alloc_tsgl, skcipher_alloc_tsgl -> af_alg_alloc_tsgl
aead_count_tsgl, skcipher_count_tsgl -> af_alg_count_tsgl
aead_pull_tsgl, skcipher_pull_tsgl -> af_alg_pull_tsgl
aead_free_areq_sgls, skcipher_free_areq_sgls -> af_alg_free_areq_sgls
aead_wait_for_wmem, skcipher_wait_for_wmem -> af_alg_wait_for_wmem
aead_wmem_wakeup, skcipher_wmem_wakeup -> af_alg_wmem_wakeup
aead_wait_for_data, skcipher_wait_for_data -> af_alg_wait_for_data
aead_data_wakeup, skcipher_data_wakeup -> af_alg_data_wakeup
aead_sendmsg, skcipher_sendmsg -> af_alg_sendmsg
aead_sendpage, skcipher_sendpage -> af_alg_sendpage
aead_async_cb, skcipher_async_cb -> af_alg_async_cb
aead_poll, skcipher_poll -> af_alg_poll

Split out the following common code from recvmsg:

af_alg_alloc_areq: allocation of the request data structure for the
cipher operation

af_alg_get_rsgl: creation of the RX SGL anchored in the request data
structure

The following changes to the implementation without affecting the
functionality have been applied to synchronize slightly different code
bases in algif_skcipher and algif_aead:

The wakeup in af_alg_wait_for_data is triggered when either more data
is received or the indicator that more data is to be expected is
released. The first is triggered by user space, the second is
triggered by the kernel upon finishing the processing of data
(i.e. the kernel is ready for more).

af_alg_sendmsg uses size_t in min_t calculation for obtaining len.
Return code determination is consistent with algif_skcipher. The
scope of the variable i is reduced to match algif_aead. The type of the
variable i is switched from int to unsigned int to match algif_aead.

af_alg_sendpage does not contain the superfluous err = 0 from
aead_sendpage.

af_alg_async_cb requires to store the number of output bytes in
areq->outlen before the AIO callback is triggered.

The POLLIN / POLLRDNORM is now set when either not more data is given or
the kernel is supplied with data. This is consistent to the wakeup from
sleep when the kernel waits for data.

The request data structure is extended by the field last_rsgl which
points to the last RX SGL list entry. This shall help recvmsg
implementation to chain the RX SGL to other SG(L)s if needed. It is
currently used by algif_aead which chains the tag SGL to the RX SGL
during decryption.

Signed-off-by: Stephan Mueller 
Signed-off-by: Herbert Xu