# git rev-parse -q --verify 21d4120ec6f5b5992b01b96ac484701163917b63^{commit}
21d4120ec6f5b5992b01b96ac484701163917b63
already have revision, skipping fetch
# git checkout -q -f -B kisskb 21d4120ec6f5b5992b01b96ac484701163917b63
# git clean -qxdf
# < git log -1
# commit 21d4120ec6f5b5992b01b96ac484701163917b63
# Author: Eric Biggers <ebiggers@google.com>
# Date:   Tue Jul 2 14:17:00 2019 -0700
# 
#     crypto: user - prevent operating on larval algorithms
#     
#     Michal Suchanek reported [1] that running the pcrypt_aead01 test from
#     LTP [2] in a loop and holding Ctrl-C causes a NULL dereference of
#     alg->cra_users.next in crypto_remove_spawns(), via crypto_del_alg().
#     The test repeatedly uses CRYPTO_MSG_NEWALG and CRYPTO_MSG_DELALG.
#     
#     The crash occurs when the instance that CRYPTO_MSG_DELALG is trying to
#     unregister isn't a real registered algorithm, but rather is a "test
#     larval", which is a special "algorithm" added to the algorithms list
#     while the real algorithm is still being tested.  Larvals don't have
#     initialized cra_users, so that causes the crash.  Normally pcrypt_aead01
#     doesn't trigger this because CRYPTO_MSG_NEWALG waits for the algorithm
#     to be tested; however, CRYPTO_MSG_NEWALG returns early when interrupted.
#     
#     Everything else in the "crypto user configuration" API has this same bug
#     too, i.e. it inappropriately allows operating on larval algorithms
#     (though it doesn't look like the other cases can cause a crash).
#     
#     Fix this by making crypto_alg_match() exclude larval algorithms.
#     
#     [1] https://lkml.kernel.org/r/20190625071624.27039-1-msuchanek@suse.de
#     [2] https://github.com/linux-test-project/ltp/blob/20190517/testcases/kernel/crypto/pcrypt_aead01.c
#     
#     Reported-by: Michal Suchanek <msuchanek@suse.de>
#     Fixes: a38f7907b926 ("crypto: Add userspace configuration API")
#     Cc: <stable@vger.kernel.org> # v3.2+
#     Cc: Steffen Klassert <steffen.klassert@secunet.com>
#     Signed-off-by: Eric Biggers <ebiggers@google.com>
#     Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
# < /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/x86_64-linux/bin/x86_64-linux-gcc --version
# < /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/x86_64-linux/bin/x86_64-linux-ld --version
# < git log --format=%s --max-count=1 21d4120ec6f5b5992b01b96ac484701163917b63
# < make -s -j 120 ARCH=x86_64 O=/kisskb/build/crypto_x86_64-allnoconfig_x86_64-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.1.0-nolibc/x86_64-linux/bin/x86_64-linux-  allnoconfig
# make -s -j 120 ARCH=x86_64 O=/kisskb/build/crypto_x86_64-allnoconfig_x86_64-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.1.0-nolibc/x86_64-linux/bin/x86_64-linux-  
Completed OK
# rm -rf /kisskb/build/crypto_x86_64-allnoconfig_x86_64-gcc8
# Build took: 0:00:11.907341