user/sven/linux.git/crypto/api.c, branch v4.9.293

crypto: api - Fix race condition in crypto_spawn_alg

2020-02-14T21:31:02Z

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

2018-09-26T06:36:37Z

[ Upstream commit e2861fa71641c6414831d628a1f4f793b6562580 ] 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 Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

crypto: api - Only abort operations on fatal signal

2015-10-20T13:59:25Z

Currently a number of Crypto API operations may fail when a signal occurs. This causes nasty problems as the caller of those operations are often not in a good position to restart the operation. In fact there is currently no need for those operations to be interrupted by user signals at all. All we need is for them to be killable. This patch replaces the relevant calls of signal_pending with fatal_signal_pending, and wait_for_completion_interruptible with wait_for_completion_killable, respectively. Cc: stable@vger.kernel.org Signed-off-by: Herbert Xu

crypto: api - prevent helper ciphers from being used

2015-03-31T13:21:03Z

Several hardware related cipher implementations are implemented as follows: a "helper" cipher implementation is registered with the kernel crypto API. Such helper ciphers are never intended to be called by normal users. In some cases, calling them via the normal crypto API may even cause failures including kernel crashes. In a normal case, the "wrapping" ciphers that use the helpers ensure that these helpers are invoked such that they cannot cause any calamity. Considering the AF_ALG user space interface, unprivileged users can call all ciphers registered with the crypto API, including these helper ciphers that are not intended to be called directly. That means, with AF_ALG user space may invoke these helper ciphers and may cause undefined states or side effects. To avoid any potential side effects with such helpers, the patch prevents the helpers to be called directly. A new cipher type flag is added: CRYPTO_ALG_INTERNAL. This flag shall be used to mark helper ciphers. These ciphers can only be used if the caller invoke the cipher with CRYPTO_ALG_INTERNAL in the type and mask field. Signed-off-by: Stephan Mueller Signed-off-by: Herbert Xu

crypto: prefix module autoloading with "crypto-"

2014-11-24T14:43:57Z

This prefixes all crypto module loading with "crypto-" so we never run the risk of exposing module auto-loading to userspace via a crypto API, as demonstrated by Mathias Krause: https://lkml.org/lkml/2013/3/4/70 Signed-off-by: Kees Cook Signed-off-by: Herbert Xu

crypto: api - Fix race condition in larval lookup

2013-09-08T04:33:50Z

crypto_larval_lookup should only return a larval if it created one. Any larval created by another entity must be processed through crypto_larval_wait before being returned. Otherwise this will lead to a larval being killed twice, which will most likely lead to a crash. Cc: stable@vger.kernel.org Reported-by: Kees Cook Tested-by: Kees Cook Signed-off-by: Herbert Xu

crypto: fix typo in comment

2013-08-20T10:39:34Z

Signed-off-by: Cristian Stoica Signed-off-by: Jiri Kosina

crypto: algboss - Hold ref count on larval

2013-06-25T11:15:17Z

On Thu, Jun 20, 2013 at 10:00:21AM +0200, Daniel Borkmann wrote: > After having fixed a NULL pointer dereference in SCTP 1abd165e ("net: > sctp: fix NULL pointer dereference in socket destruction"), I ran into > the following NULL pointer dereference in the crypto subsystem with > the same reproducer, easily hit each time: > > BUG: unable to handle kernel NULL pointer dereference at (null) > IP: [] __wake_up_common+0x31/0x90 > PGD 0 > Oops: 0000 [#1] SMP > Modules linked in: padlock_sha(F-) sha256_generic(F) sctp(F) libcrc32c(F) [..] > CPU: 6 PID: 3326 Comm: cryptomgr_probe Tainted: GF 3.10.0-rc5+ #1 > Hardware name: Dell Inc. PowerEdge T410/0H19HD, BIOS 1.6.3 02/01/2011 > task: ffff88007b6cf4e0 ti: ffff88007b7cc000 task.ti: ffff88007b7cc000 > RIP: 0010:[] [] __wake_up_common+0x31/0x90 > RSP: 0018:ffff88007b7cde08 EFLAGS: 00010082 > RAX: ffffffffffffffe8 RBX: ffff88003756c130 RCX: 0000000000000000 > RDX: 0000000000000000 RSI: 0000000000000003 RDI: ffff88003756c130 > RBP: ffff88007b7cde48 R08: 0000000000000000 R09: ffff88012b173200 > R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000282 > R13: ffff88003756c138 R14: 0000000000000000 R15: 0000000000000000 > FS: 0000000000000000(0000) GS:ffff88012fc60000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b > CR2: 0000000000000000 CR3: 0000000001a0b000 CR4: 00000000000007e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 > Stack: > ffff88007b7cde28 0000000300000000 ffff88007b7cde28 ffff88003756c130 > 0000000000000282 ffff88003756c128 ffffffff81227670 0000000000000000 > ffff88007b7cde78 ffffffff810722b7 ffff88007cdcf000 ffffffff81a90540 > Call Trace: > [] ? crypto_alloc_pcomp+0x20/0x20 > [] complete_all+0x47/0x60 > [] cryptomgr_probe+0x98/0xc0 > [] ? crypto_alloc_pcomp+0x20/0x20 > [] kthread+0xce/0xe0 > [] ? kthread_freezable_should_stop+0x70/0x70 > [] ret_from_fork+0x7c/0xb0 > [] ? kthread_freezable_should_stop+0x70/0x70 > Code: 41 56 41 55 41 54 53 48 83 ec 18 66 66 66 66 90 89 75 cc 89 55 c8 > 4c 8d 6f 08 48 8b 57 08 41 89 cf 4d 89 c6 48 8d 42 e > RIP [] __wake_up_common+0x31/0x90 > RSP > CR2: 0000000000000000 > ---[ end trace b495b19270a4d37e ]--- > > My assumption is that the following is happening: the minimal SCTP > tool runs under ``echo 1 > /proc/sys/net/sctp/auth_enable'', hence > it's making use of crypto_alloc_hash() via sctp_auth_init_hmacs(). > It forks itself, heavily allocates, binds, listens and waits in > accept on sctp sockets, and then randomly kills some of them (no > need for an actual client in this case to hit this). Then, again, > allocating, binding, etc, and then killing child processes. > > The problem that might be happening here is that cryptomgr requests > the module to probe/load through cryptomgr_schedule_probe(), but > before the thread handler cryptomgr_probe() returns, we return from > the wait_for_completion_interruptible() function and probably already > have cleared up larval, thus we run into a NULL pointer dereference > when in cryptomgr_probe() complete_all() is being called. > > If we wait with wait_for_completion() instead, this panic will not > occur anymore. This is valid, because in case a signal is pending, > cryptomgr_probe() returns from probing anyway with properly calling > complete_all(). The use of wait_for_completion_interruptible is intentional so that we don't lock up the thread if a bug causes us to never wake up. This bug is caused by the helper thread using the larval without holding a reference count on it. If the helper thread completes after the original thread requesting for help has gone away and destroyed the larval, then we get the crash above. So the fix is to hold a reference count on the larval. Cc: # 3.6+ Reported-by: Daniel Borkmann Tested-by: Daniel Borkmann Signed-off-by: Herbert Xu

crypto: api - Fix checkpatch errors

2010-02-16T12:26:46Z

Signed-off-by: Richard Hartmann Signed-off-by: Herbert Xu

crypto: api - Remove frontend argument from extsize/init_tfm

2009-07-14T04:58:15Z

As the extsize and init_tfm functions belong to the frontend the frontend argument is superfluous. Signed-off-by: Herbert Xu