linux/crypto/algapi.c, branch v5.8

crypto: algapi - create function to add request in front of queue

2020-05-08T05:30:40Z

Add crypto_enqueue_request_head function that enqueues a request in front of queue. This will be used in crypto-engine, on error path. In case a request was not executed by hardware, enqueue it back in front of queue (to keep the order of requests). Signed-off-by: Iuliana Prodan Signed-off-by: Herbert Xu

crypto: api - Fix use-after-free and race in crypto_spawn_alg

2020-04-16T06:49:22Z

There are two problems in crypto_spawn_alg. First of all it may return spawn->alg even if spawn->dead is set. This results in a double-free as detected by syzbot. Secondly the setting of the DYING flag is racy because we hold the read-lock instead of the write-lock. We should instead call crypto_shoot_alg in a safe manner by gaining a refcount, dropping the lock, and then releasing the refcount. This patch fixes both problems. Reported-by: syzbot+fc0674cde00b66844470@syzkaller.appspotmail.com Fixes: 4f87ee118d16 ("crypto: api - Do not zap spawn->alg") Fixes: 73669cc55646 ("crypto: api - Fix race condition in...") Cc: Signed-off-by: Herbert Xu

crypto: algapi - Avoid spurious modprobe on LOADED

2020-04-16T06:49:22Z

Currently after any algorithm is registered and tested, there's an unnecessary request_module("cryptomgr") even if it's already loaded. Also, CRYPTO_MSG_ALG_LOADED is sent twice, and thus if the algorithm is "crct10dif", lib/crc-t10dif.c replaces the tfm twice rather than once. This occurs because CRYPTO_MSG_ALG_LOADED is sent using crypto_probing_notify(), which tries to load "cryptomgr" if the notification is not handled (NOTIFY_DONE). This doesn't make sense because "cryptomgr" doesn't handle this notification. Fix this by using crypto_notify() instead of crypto_probing_notify(). Fixes: dd8b083f9a5e ("crypto: api - Introduce notifier for new crypto algorithms") Cc: # v4.20+ Cc: Martin K. Petersen Signed-off-by: Eric Biggers Reviewed-by: Martin K. Petersen Signed-off-by: Herbert Xu

crypto: algapi - remove crypto_template::{alloc,free}()

2020-01-09T03:30:58Z

Now that all templates provide a ->create() method which creates an instance, installs a strongly-typed ->free() method directly to it, and registers it, the older ->alloc() and ->free() methods in 'struct crypto_template' are no longer used. Remove them. Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu

crypto: algapi - fold crypto_init_spawn() into crypto_grab_spawn()

2020-01-09T03:30:57Z

Now that crypto_init_spawn() is only called by crypto_grab_spawn(), simplify things by moving its functionality into crypto_grab_spawn(). In the process of doing this, also be more consistent about when the spawn and instance are updated, and remove the crypto_spawn::dropref flag since now it's always set. Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu

crypto: algapi - remove obsoleted instance creation helpers

2020-01-09T03:30:57Z

Remove lots of helper functions that were previously used for instantiating crypto templates, but are now unused: - crypto_get_attr_alg() and similar functions looked up an inner algorithm directly from a template parameter. These were replaced with getting the algorithm's name, then calling crypto_grab_*(). - crypto_init_spawn2() and similar functions initialized a spawn, given an algorithm. Similarly, these were replaced with crypto_grab_*(). - crypto_alloc_instance() and similar functions allocated an instance with a single spawn, given the inner algorithm. These aren't useful anymore since crypto_grab_*() need the instance allocated first. Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu

crypto: algapi - pass instance to crypto_grab_spawn()

2020-01-09T03:30:54Z

Currently, crypto_spawn::inst is first used temporarily to pass the instance to crypto_grab_spawn(). Then crypto_init_spawn() overwrites it with crypto_spawn::next, which shares the same union. Finally, crypto_spawn::inst is set again when the instance is registered. Make this less convoluted by just passing the instance as an argument to crypto_grab_spawn() instead. Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu

crypto: algapi - make crypto_grab_spawn() handle an ERR_PTR() name

2020-01-09T03:30:53Z

To allow further simplifying template ->create() functions, make crypto_grab_spawn() handle an ERR_PTR() name by passing back the error. For most templates, this will allow the result of crypto_attr_alg_name() to be passed directly to crypto_grab_*(), rather than first having to assign it to a variable [where it can then potentially be misused, as it was in the rfc7539 template prior to commit 5e27f38f1f3f ("crypto: chacha20poly1305 - set cra_name correctly")] and check it for error. Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu

crypto: algapi - make crypto_drop_spawn() a no-op on uninitialized spawns

2020-01-09T03:30:53Z

Make crypto_drop_spawn() do nothing when the spawn hasn't been initialized with an algorithm yet. This will allow simplifying error handling in all the template ->create() functions, since on error they will be able to just call their usual "free instance" function, rather than having to handle dropping just the spawns that have been initialized so far. This does assume the spawn starts out zero-filled, but that's always the case since instances are allocated with kzalloc(). And some other code already assumes this anyway. Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu

crypto: api - Retain alg refcount in crypto_grab_spawn

2019-12-27T10:18:03Z

This patch changes crypto_grab_spawn to retain the reference count on the algorithm. This is because the caller needs to access the algorithm parameters and without the reference count the algorithm can be freed at any time. The reference count will be subsequently dropped by the crypto API once the instance has been registered. The helper crypto_drop_spawn will also conditionally drop the reference count depending on whether it has been registered. Note that the code is actually added to crypto_init_spawn. However, unless the caller activates this by setting spawn->dropref beforehand then nothing happens. The only caller that sets dropref is currently crypto_grab_spawn. Once all legacy users of crypto_init_spawn disappear, then we can kill the dropref flag. Internally each instance will maintain a list of its spawns prior to registration. This memory used by this list is shared with other fields that are only used after registration. In order for this to work a new flag spawn->registered is added to indicate whether spawn->inst can be used. Fixes: d6ef2f198d4c ("crypto: api - Add crypto_grab_spawn primitive") Signed-off-by: Herbert Xu