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Daniel Jordan 894c9ef978 padata: validate cpumask without removed CPU during offline
Configuring an instance's parallel mask without any online CPUs...

  echo 2 > /sys/kernel/pcrypt/pencrypt/parallel_cpumask
  echo 0 > /sys/devices/system/cpu/cpu1/online

...makes tcrypt mode=215 crash like this:

  divide error: 0000 [#1] SMP PTI
  CPU: 4 PID: 283 Comm: modprobe Not tainted 5.4.0-rc8-padata-doc-v2+ #2
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20191013_105130-anatol 04/01/2014
  RIP: 0010:padata_do_parallel+0x114/0x300
  Call Trace:
   pcrypt_aead_encrypt+0xc0/0xd0 [pcrypt]
   crypto_aead_encrypt+0x1f/0x30
   do_mult_aead_op+0x4e/0xdf [tcrypt]
   test_mb_aead_speed.constprop.0.cold+0x226/0x564 [tcrypt]
   do_test+0x28c2/0x4d49 [tcrypt]
   tcrypt_mod_init+0x55/0x1000 [tcrypt]
   ...

cpumask_weight() in padata_cpu_hash() returns 0 because the mask has no
CPUs.  The problem is __padata_remove_cpu() checks for valid masks too
early and so doesn't mark the instance PADATA_INVALID as expected, which
would have made padata_do_parallel() return error before doing the
division.

Fix by introducing a second padata CPU hotplug state before
CPUHP_BRINGUP_CPU so that __padata_remove_cpu() sees the online mask
without @cpu.  No need for the second argument to padata_replace() since
@cpu is now already missing from the online mask.

Fixes: 33e5445068 ("padata: Handle empty padata cpumasks")
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-12-11 16:37:02 +08:00
arch crypto: arm64/ghash-neon - bump priority to 150 2019-12-11 16:36:55 +08:00
block block: fix memleak of bio integrity data 2019-12-05 11:38:36 -07:00
certs certs: Add wrapper function to check blacklisted binary hash 2019-11-12 12:25:50 +11:00
crypto crypto: cipher - remove crt_u.cipher (struct cipher_tfm) 2019-12-11 16:37:01 +08:00
Documentation dt-bindings: rng: add BCM2711 RNG compatible 2019-12-11 16:34:45 +08:00
drivers crypto: omap-crypto - copy the temporary data to output buffer properly 2019-12-11 16:37:00 +08:00
fs crypto: skcipher - remove crypto_skcipher::keysize 2019-12-11 16:36:56 +08:00
include padata: validate cpumask without removed CPU during offline 2019-12-11 16:37:02 +08:00
init init/Kconfig: fix indentation 2019-12-04 19:44:13 -08:00
ipc y2038: remove CONFIG_64BIT_TIME 2019-11-15 14:38:27 +01:00
kernel padata: validate cpumask without removed CPU during offline 2019-12-11 16:37:02 +08:00
lib lib/: fix Kconfig indentation 2019-12-07 11:00:19 -08:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm Merge branch 'akpm' (patches from Andrew) 2019-12-05 09:46:26 -08:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-12-08 13:28:11 -08:00
samples samples/bpf: Fix broken xdp_rxq_info due to map order assumptions 2019-12-04 17:54:15 -08:00
scripts Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-12-08 13:28:11 -08:00
security + Features 2019-12-03 12:51:35 -08:00
sound sound updates #2 for 5.5-rc1 2019-12-06 13:06:14 -08:00
tools Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-12-08 13:28:11 -08:00
usr arch: sembuf.h: make uapi asm/sembuf.h self-contained 2019-12-04 19:44:14 -08:00
virt KVM: Fix jump label out_free_* in kvm_init() 2019-11-23 11:29:17 +01:00
.clang-format clang-format: Update with the latest for_each macro list 2019-08-31 10:00:51 +02:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore modpost: dump missing namespaces into a single modules.nsdeps file 2019-11-11 20:10:01 +09:00
.mailmap MAINTAINERS: update my e-mail address 2019-12-11 16:36:05 +08:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS Linux 5.4-rc4 2019-10-29 04:43:29 -06:00
Kbuild kbuild: do not descend to ./Kbuild when cleaning 2019-08-21 21:03:58 +09:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS MAINTAINERS: update my e-mail address 2019-12-11 16:36:05 +08:00
Makefile Linux 5.5-rc1 2019-12-08 14:57:55 -08:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.