linux-stable.git/crypto/api.c, branch v4.19.232

crypto: api - check for ERR pointers in crypto_destroy_tfm()

2021-05-22T08:59:14+00:00

[ Upstream commit 83681f2bebb34dbb3f03fecd8f570308ab8b7c2c ]

Given that crypto_alloc_tfm() may return ERR pointers, and to avoid
crashes on obscure error paths where such pointers are presented to
crypto_destroy_tfm() (such as [0]), add an ERR_PTR check there
before dereferencing the second argument as a struct crypto_tfm
pointer.

[0] https://lore.kernel.org/linux-crypto/000000000000de949705bc59e0f6@google.com/

Reported-by: syzbot+12cf5fbfdeba210a89dd@syzkaller.appspotmail.com
Reviewed-by: Eric Biggers 
Signed-off-by: Ard Biesheuvel 
Signed-off-by: Herbert Xu 
Signed-off-by: Sasha Levin

crypto: api - Fix race condition in crypto_spawn_alg

2020-02-11T12:34:05+00:00

commit 73669cc556462f4e50376538d77ee312142e8a8a upstream.

The function crypto_spawn_alg is racy because it drops the lock
before shooting the dying algorithm.  The algorithm could disappear
altogether before we shoot it.

This patch fixes it by moving the shooting into the locked section.

Fixes: 6bfd48096ff8 ("[CRYPTO] api: Added spawns")
Signed-off-by: Herbert Xu 
Signed-off-by: Greg Kroah-Hartman

evm: Don't deadlock if a crypto algorithm is unavailable

2018-07-18T11:27:22+00:00

When EVM attempts to appraise a file signed with a crypto algorithm the
kernel doesn't have support for, it will cause the kernel to trigger a
module load. If the EVM policy includes appraisal of kernel modules this
will in turn call back into EVM - since EVM is holding a lock until the
crypto initialisation is complete, this triggers a deadlock. Add a
CRYPTO_NOLOAD flag and skip module loading if it's set, and add that flag
in the EVM case in order to fail gracefully with an error message
instead of deadlocking.

Signed-off-by: Matthew Garrett 
Acked-by: Herbert Xu 
Signed-off-by: Mimi Zohar

crypto: api - fix finding algorithm currently being tested

2018-04-20T16:24:02+00:00

Commit eb02c38f0197 ("crypto: api - Keep failed instances alive") is
making allocating crypto transforms sometimes fail with ELIBBAD, when
multiple processes try to access encrypted files with fscrypt for the
first time since boot.  The problem is that the "request larval" for the
algorithm is being mistaken for an algorithm which failed its tests.

Fix it by only returning ELIBBAD for "non-larval" algorithms.  Also
don't leak a reference to the algorithm.

Fixes: eb02c38f0197 ("crypto: api - Keep failed instances alive")
Signed-off-by: Eric Biggers 
Signed-off-by: Herbert Xu

crypto: api - Keep failed instances alive

2018-03-30T17:32:58+00:00

This patch reverts commit 9c521a200bc3 ("crypto: api - remove
instance when test failed") and fixes the underlying problem
in a different way.

To recap, prior to the reverted commit, an instance that fails
a self-test is kept around.  However, it would satisfy any new
lookups against its name and therefore the system may accumlulate
an unbounded number of failed instances for the same algorithm
name.

The reverted commit fixed it by unregistering the instance.  Hoever,
this still does not prevent the creation of the same failed instance
over and over again each time the name is looked up.

This patch fixes it by keeping the failed instance around, just as
we would if it were a normal algorithm.  However, the lookup code
has been udpated so that we do not attempt to create another
instance as long as this failed one is still registered.  Of course,
you could still force a new creation by deleting the instance from
user-space.

A new error (ELIBBAD) has been commandeered for this purpose and
will be returned when all registered algorithm of a given name
have failed the self-test.

Signed-off-by: Herbert Xu

crypto: api - Make crypto_alg_lookup static

2018-03-30T17:32:58+00:00

The function crypto_alg_lookup is only usd within the crypto API
and should be not be exported to the modules.  This patch marks
it as a static function.

Signed-off-by: Herbert Xu

crypto: api - Remove unused crypto_type lookup function

2018-03-30T17:32:57+00:00

The lookup function in crypto_type was only used for the implicit
IV generators which have been completely removed from the crypto
API.

This patch removes the lookup function as it is now useless.

Signed-off-by: Herbert Xu

crypto: algapi - convert cra_refcnt to refcount_t

2018-01-05T07:43:09+00:00

Reference counters should use refcount_t rather than atomic_t, since the
refcount_t implementation can prevent overflows, reducing the
exploitability of reference leak bugs.  crypto_alg.cra_refcount is a
reference counter with the usual semantics, so switch it over to
refcount_t.

Signed-off-by: Eric Biggers 
Signed-off-by: Herbert Xu

crypto: api - Unexport crypto_larval_lookup()

2017-12-22T08:29:06+00:00

crypto_larval_lookup() is not used outside of crypto/api.c, so unexport
it and mark it 'static'.

Signed-off-by: Eric Biggers 
Signed-off-by: Herbert Xu

crypto: introduce crypto wait for async op

2017-11-03T14:11:18+00:00

Invoking a possibly async. crypto op and waiting for completion
while correctly handling backlog processing is a common task
in the crypto API implementation and outside users of it.

This patch adds a generic implementation for doing so in
preparation for using it across the board instead of hand
rolled versions.

Signed-off-by: Gilad Ben-Yossef 
CC: Eric Biggers 
CC: Jonathan Cameron 
Signed-off-by: Herbert Xu