Commit Graph

284 Commits

Author SHA1 Message Date
George Spelvin
c51f8f88d7 random32: make prandom_u32() output unpredictable
Non-cryptographic PRNGs may have great statistical properties, but
are usually trivially predictable to someone who knows the algorithm,
given a small sample of their output.  An LFSR like prandom_u32() is
particularly simple, even if the sample is widely scattered bits.

It turns out the network stack uses prandom_u32() for some things like
random port numbers which it would prefer are *not* trivially predictable.
Predictability led to a practical DNS spoofing attack.  Oops.

This patch replaces the LFSR with a homebrew cryptographic PRNG based
on the SipHash round function, which is in turn seeded with 128 bits
of strong random key.  (The authors of SipHash have *not* been consulted
about this abuse of their algorithm.)  Speed is prioritized over security;
attacks are rare, while performance is always wanted.

Replacing all callers of prandom_u32() is the quick fix.
Whether to reinstate a weaker PRNG for uses which can tolerate it
is an open question.

Commit f227e3ec3b ("random32: update the net random state on interrupt
and activity") was an earlier attempt at a solution.  This patch replaces
it.

Reported-by: Amit Klein <aksecurity@gmail.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Eric Dumazet <edumazet@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: tytso@mit.edu
Cc: Florian Westphal <fw@strlen.de>
Cc: Marc Plumb <lkml.mplumb@gmail.com>
Fixes: f227e3ec3b ("random32: update the net random state on interrupt and activity")
Signed-off-by: George Spelvin <lkml@sdf.org>
Link: https://lore.kernel.org/netdev/20200808152628.GA27941@SDF.ORG/
[ willy: partial reversal of f227e3ec3b5c; moved SIPROUND definitions
  to prandom.h for later use; merged George's prandom_seed() proposal;
  inlined siprand_u32(); replaced the net_rand_state[] array with 4
  members to fix a build issue; cosmetic cleanups to make checkpatch
  happy; fixed RANDOM32_SELFTEST build ]
Signed-off-by: Willy Tarreau <w@1wt.eu>
2020-10-24 20:21:57 +02:00
Willy Tarreau
f227e3ec3b random32: update the net random state on interrupt and activity
This modifies the first 32 bits out of the 128 bits of a random CPU's
net_rand_state on interrupt or CPU activity to complicate remote
observations that could lead to guessing the network RNG's internal
state.

Note that depending on some network devices' interrupt rate moderation
or binding, this re-seeding might happen on every packet or even almost
never.

In addition, with NOHZ some CPUs might not even get timer interrupts,
leaving their local state rarely updated, while they are running
networked processes making use of the random state.  For this reason, we
also perform this update in update_process_times() in order to at least
update the state when there is user or system activity, since it's the
only case we care about.

Reported-by: Amit Klein <aksecurity@gmail.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-07-29 10:35:37 -07:00
Linus Torvalds
1c38372662 Merge branch 'work.sysctl' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull sysctl fixes from Al Viro:
 "Fixups to regressions in sysctl series"

* 'work.sysctl' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  sysctl: reject gigantic reads/write to sysctl files
  cdrom: fix an incorrect __user annotation on cdrom_sysctl_info
  trace: fix an incorrect __user annotation on stack_trace_sysctl
  random: fix an incorrect __user annotation on proc_do_entropy
  net/sysctl: remove leftover __user annotations on neigh_proc_dointvec*
  net/sysctl: use cpumask_parse in flow_limit_cpu_sysctl
2020-06-10 16:05:54 -07:00
Christoph Hellwig
a2541dcb51 random: fix an incorrect __user annotation on proc_do_entropy
No user pointers for sysctls anymore.

Fixes: 32927393dc ("sysctl: pass kernel pointers to ->proc_handler")
Reported-by: build test robot <lkp@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-06-08 10:13:56 -04:00
Linus Torvalds
cb8e59cc87 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking updates from David Miller:

 1) Allow setting bluetooth L2CAP modes via socket option, from Luiz
    Augusto von Dentz.

 2) Add GSO partial support to igc, from Sasha Neftin.

 3) Several cleanups and improvements to r8169 from Heiner Kallweit.

 4) Add IF_OPER_TESTING link state and use it when ethtool triggers a
    device self-test. From Andrew Lunn.

 5) Start moving away from custom driver versions, use the globally
    defined kernel version instead, from Leon Romanovsky.

 6) Support GRO vis gro_cells in DSA layer, from Alexander Lobakin.

 7) Allow hard IRQ deferral during NAPI, from Eric Dumazet.

 8) Add sriov and vf support to hinic, from Luo bin.

 9) Support Media Redundancy Protocol (MRP) in the bridging code, from
    Horatiu Vultur.

10) Support netmap in the nft_nat code, from Pablo Neira Ayuso.

11) Allow UDPv6 encapsulation of ESP in the ipsec code, from Sabrina
    Dubroca. Also add ipv6 support for espintcp.

12) Lots of ReST conversions of the networking documentation, from Mauro
    Carvalho Chehab.

13) Support configuration of ethtool rxnfc flows in bcmgenet driver,
    from Doug Berger.

14) Allow to dump cgroup id and filter by it in inet_diag code, from
    Dmitry Yakunin.

15) Add infrastructure to export netlink attribute policies to
    userspace, from Johannes Berg.

16) Several optimizations to sch_fq scheduler, from Eric Dumazet.

17) Fallback to the default qdisc if qdisc init fails because otherwise
    a packet scheduler init failure will make a device inoperative. From
    Jesper Dangaard Brouer.

18) Several RISCV bpf jit optimizations, from Luke Nelson.

19) Correct the return type of the ->ndo_start_xmit() method in several
    drivers, it's netdev_tx_t but many drivers were using
    'int'. From Yunjian Wang.

20) Add an ethtool interface for PHY master/slave config, from Oleksij
    Rempel.

21) Add BPF iterators, from Yonghang Song.

22) Add cable test infrastructure, including ethool interfaces, from
    Andrew Lunn. Marvell PHY driver is the first to support this
    facility.

23) Remove zero-length arrays all over, from Gustavo A. R. Silva.

24) Calculate and maintain an explicit frame size in XDP, from Jesper
    Dangaard Brouer.

25) Add CAP_BPF, from Alexei Starovoitov.

26) Support terse dumps in the packet scheduler, from Vlad Buslov.

27) Support XDP_TX bulking in dpaa2 driver, from Ioana Ciornei.

28) Add devm_register_netdev(), from Bartosz Golaszewski.

29) Minimize qdisc resets, from Cong Wang.

30) Get rid of kernel_getsockopt and kernel_setsockopt in order to
    eliminate set_fs/get_fs calls. From Christoph Hellwig.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2517 commits)
  selftests: net: ip_defrag: ignore EPERM
  net_failover: fixed rollback in net_failover_open()
  Revert "tipc: Fix potential tipc_aead refcnt leak in tipc_crypto_rcv"
  Revert "tipc: Fix potential tipc_node refcnt leak in tipc_rcv"
  vmxnet3: allow rx flow hash ops only when rss is enabled
  hinic: add set_channels ethtool_ops support
  selftests/bpf: Add a default $(CXX) value
  tools/bpf: Don't use $(COMPILE.c)
  bpf, selftests: Use bpf_probe_read_kernel
  s390/bpf: Use bcr 0,%0 as tail call nop filler
  s390/bpf: Maintain 8-byte stack alignment
  selftests/bpf: Fix verifier test
  selftests/bpf: Fix sample_cnt shared between two threads
  bpf, selftests: Adapt cls_redirect to call csum_level helper
  bpf: Add csum_level helper for fixing up csum levels
  bpf: Fix up bpf_skb_adjust_room helper's skb csum setting
  sfc: add missing annotation for efx_ef10_try_update_nic_stats_vf()
  crypto/chtls: IPv6 support for inline TLS
  Crypto/chcr: Fixes a coccinile check error
  Crypto/chcr: Fixes compilations warnings
  ...
2020-06-03 16:27:18 -07:00
Eric Biggers
228c4f265c crypto: lib/sha1 - fold linux/cryptohash.h into crypto/sha.h
<linux/cryptohash.h> sounds very generic and important, like it's the
header to include if you're doing cryptographic hashing in the kernel.
But actually it only includes the library implementation of the SHA-1
compression function (not even the full SHA-1).  This should basically
never be used anymore; SHA-1 is no longer considered secure, and there
are much better ways to do cryptographic hashing in the kernel.

Remove this header and fold it into <crypto/sha.h> which already
contains constants and functions for SHA-1 (along with SHA-2).

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-05-08 15:32:17 +10:00
Eric Biggers
6b0b0fa2bc crypto: lib/sha1 - rename "sha" to "sha1"
The library implementation of the SHA-1 compression function is
confusingly called just "sha_transform()".  Alongside it are some "SHA_"
constants and "sha_init()".  Presumably these are left over from a time
when SHA just meant SHA-1.  But now there are also SHA-2 and SHA-3, and
moreover SHA-1 is now considered insecure and thus shouldn't be used.

Therefore, rename these functions and constants to make it very clear
that they are for SHA-1.  Also add a comment to make it clear that these
shouldn't be used.

For the extra-misleadingly named "SHA_MESSAGE_BYTES", rename it to
SHA1_BLOCK_SIZE and define it to just '64' rather than '(512/8)' so that
it matches the same definition in <crypto/sha.h>.  This prepares for
merging <linux/cryptohash.h> into <crypto/sha.h>.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-05-08 15:32:17 +10:00
Christoph Hellwig
32927393dc sysctl: pass kernel pointers to ->proc_handler
Instead of having all the sysctl handlers deal with user pointers, which
is rather hairy in terms of the BPF interaction, copy the input to and
from  userspace in common code.  This also means that the strings are
always NUL-terminated by the common code, making the API a little bit
safer.

As most handler just pass through the data to one of the common handlers
a lot of the changes are mechnical.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-04-27 02:07:40 -04:00
Mark Rutland
ab9a7e2704 random: avoid warnings for !CONFIG_NUMA builds
As crng_initialize_secondary() is only called by do_numa_crng_init(),
and the latter is under ifdeffery for CONFIG_NUMA, when CONFIG_NUMA is
not selected the compiler will warn that the former is unused:

| drivers/char/random.c:820:13: warning: 'crng_initialize_secondary' defined but not used [-Wunused-function]
|   820 | static void crng_initialize_secondary(struct crng_state *crng)
|       |             ^~~~~~~~~~~~~~~~~~~~~~~~~

Stephen reports that this happens for x86_64 noallconfig builds.

We could move crng_initialize_secondary() and crng_init_try_arch() under
the CONFIG_NUMA ifdeffery, but this has the unfortunate property of
separating them from crng_initialize_primary() and
crng_init_try_arch_early() respectively. Instead, let's mark
crng_initialize_secondary() as __maybe_unused.

Link: https://lore.kernel.org/r/20200310121747.GA49602@lakrids.cambridge.arm.com
Fixes: 5cbe0f13b5 ("random: split primary/secondary crng init paths")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-03-18 23:28:17 -04:00
Qian Cai
e00d996a43 random: fix data races at timer_rand_state
Fields in "struct timer_rand_state" could be accessed concurrently.
Lockless plain reads and writes result in data races. Fix them by adding
pairs of READ|WRITE_ONCE(). The data races were reported by KCSAN,

 BUG: KCSAN: data-race in add_timer_randomness / add_timer_randomness

 write to 0xffff9f320a0a01d0 of 8 bytes by interrupt on cpu 22:
  add_timer_randomness+0x100/0x190
  add_timer_randomness at drivers/char/random.c:1152
  add_disk_randomness+0x85/0x280
  scsi_end_request+0x43a/0x4a0
  scsi_io_completion+0xb7/0x7e0
  scsi_finish_command+0x1ed/0x2a0
  scsi_softirq_done+0x1c9/0x1d0
  blk_done_softirq+0x181/0x1d0
  __do_softirq+0xd9/0x57c
  irq_exit+0xa2/0xc0
  do_IRQ+0x8b/0x190
  ret_from_intr+0x0/0x42
  cpuidle_enter_state+0x15e/0x980
  cpuidle_enter+0x69/0xc0
  call_cpuidle+0x23/0x40
  do_idle+0x248/0x280
  cpu_startup_entry+0x1d/0x1f
  start_secondary+0x1b2/0x230
  secondary_startup_64+0xb6/0xc0

 no locks held by swapper/22/0.
 irq event stamp: 32871382
 _raw_spin_unlock_irqrestore+0x53/0x60
 _raw_spin_lock_irqsave+0x21/0x60
 _local_bh_enable+0x21/0x30
 irq_exit+0xa2/0xc0

 read to 0xffff9f320a0a01d0 of 8 bytes by interrupt on cpu 2:
  add_timer_randomness+0xe8/0x190
  add_disk_randomness+0x85/0x280
  scsi_end_request+0x43a/0x4a0
  scsi_io_completion+0xb7/0x7e0
  scsi_finish_command+0x1ed/0x2a0
  scsi_softirq_done+0x1c9/0x1d0
  blk_done_softirq+0x181/0x1d0
  __do_softirq+0xd9/0x57c
  irq_exit+0xa2/0xc0
  do_IRQ+0x8b/0x190
  ret_from_intr+0x0/0x42
  cpuidle_enter_state+0x15e/0x980
  cpuidle_enter+0x69/0xc0
  call_cpuidle+0x23/0x40
  do_idle+0x248/0x280
  cpu_startup_entry+0x1d/0x1f
  start_secondary+0x1b2/0x230
  secondary_startup_64+0xb6/0xc0

 no locks held by swapper/2/0.
 irq event stamp: 37846304
 _raw_spin_unlock_irqrestore+0x53/0x60
 _raw_spin_lock_irqsave+0x21/0x60
 _local_bh_enable+0x21/0x30
 irq_exit+0xa2/0xc0

 Reported by Kernel Concurrency Sanitizer on:
 Hardware name: HP ProLiant BL660c Gen9, BIOS I38 10/17/2018

Link: https://lore.kernel.org/r/1582648024-13111-1-git-send-email-cai@lca.pw
Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-02-27 23:21:53 -05:00
Jason A. Donenfeld
69efea712f random: always use batched entropy for get_random_u{32,64}
It turns out that RDRAND is pretty slow. Comparing these two
constructions:

  for (i = 0; i < CHACHA_BLOCK_SIZE; i += sizeof(ret))
    arch_get_random_long(&ret);

and

  long buf[CHACHA_BLOCK_SIZE / sizeof(long)];
  extract_crng((u8 *)buf);

it amortizes out to 352 cycles per long for the top one and 107 cycles
per long for the bottom one, on Coffee Lake Refresh, Intel Core i9-9880H.

And importantly, the top one has the drawback of not benefiting from the
real rng, whereas the bottom one has all the nice benefits of using our
own chacha rng. As get_random_u{32,64} gets used in more places (perhaps
beyond what it was originally intended for when it was introduced as
get_random_{int,long} back in the md5 monstrosity era), it seems like it
might be a good thing to strengthen its posture a tiny bit. Doing this
should only be stronger and not any weaker because that pool is already
initialized with a bunch of rdrand data (when available). This way, we
get the benefits of the hardware rng as well as our own rng.

Another benefit of this is that we no longer hit pitfalls of the recent
stream of AMD bugs in RDRAND. One often used code pattern for various
things is:

  do {
  	val = get_random_u32();
  } while (hash_table_contains_key(val));

That recent AMD bug rendered that pattern useless, whereas we're really
very certain that chacha20 output will give pretty distributed numbers,
no matter what.

So, this simplification seems better both from a security perspective
and from a performance perspective.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20200221201037.30231-1-Jason@zx2c4.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-02-27 23:21:52 -05:00
Mark Rutland
253d3194c2 random: add arch_get_random_*long_early()
Some architectures (e.g. arm64) can have heterogeneous CPUs, and the
boot CPU may be able to provide entropy while secondary CPUs cannot. On
such systems, arch_get_random_long() and arch_get_random_seed_long()
will fail unless support for RNG instructions has been detected on all
CPUs. This prevents the boot CPU from being able to provide
(potentially) trusted entropy when seeding the primary CRNG.

To make it possible to seed the primary CRNG from the boot CPU without
adversely affecting the runtime versions of arch_get_random_long() and
arch_get_random_seed_long(), this patch adds new early versions of the
functions used when initializing the primary CRNG.

Default implementations are provided atop of the existing
arch_get_random_long() and arch_get_random_seed_long() so that only
architectures with such constraints need to provide the new helpers.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20200210130015.17664-3-mark.rutland@arm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-02-27 23:21:52 -05:00
Mark Rutland
5cbe0f13b5 random: split primary/secondary crng init paths
Currently crng_initialize() is used for both the primary CRNG and
secondary CRNGs. While we wish to share common logic, we need to do a
number of additional things for the primary CRNG, and this would be
easier to deal with were these handled in separate functions.

This patch splits crng_initialize() into crng_initialize_primary() and
crng_initialize_secondary(), with common logic factored out into a
crng_init_try_arch() helper.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20200210130015.17664-2-mark.rutland@arm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-02-27 23:21:52 -05:00
Yangtao Li
09a6d00a42 random: remove some dead code of poolinfo
Since it is not being used, so delete it.

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Link: https://lore.kernel.org/r/20190607182517.28266-5-tiny.windzz@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-01-07 17:08:13 -05:00
Yangtao Li
727d499a6f random: fix typo in add_timer_randomness()
s/entimate/estimate

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Link: https://lore.kernel.org/r/20190607182517.28266-4-tiny.windzz@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-01-07 17:08:13 -05:00
Yangtao Li
12cd53aff5 random: Add and use pr_fmt()
Prefix all printk/pr_<level> messages with "random: " to make the
logging a bit more consistent.

Miscellanea:

o Convert a printks to pr_notice
o Whitespace to align to open parentheses
o Remove embedded "random: " from pr_* as pr_fmt adds it

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Link: https://lore.kernel.org/r/20190607182517.28266-3-tiny.windzz@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-01-07 17:07:30 -05:00
Yangtao Li
12faac30d1 random: convert to ENTROPY_BITS for better code readability
Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Link: https://lore.kernel.org/r/20190607182517.28266-2-tiny.windzz@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-01-07 16:33:18 -05:00
Yangtao Li
870e05b1b1 random: remove unnecessary unlikely()
WARN_ON() already contains an unlikely(), so it's not necessary to use
unlikely.

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Link: https://lore.kernel.org/r/20190607182517.28266-1-tiny.windzz@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-01-07 16:10:28 -05:00
Andy Lutomirski
c95ea0c69f random: remove kernel.random.read_wakeup_threshold
It has no effect any more, so remove it.  We can revert this if
there is some user code that expects to be able to set this sysctl.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/a74ed2cf0b5a5451428a246a9239f5bc4e29358f.1577088521.git.luto@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-01-07 16:07:01 -05:00
Andy Lutomirski
84df7cdfbb random: delete code to pull data into pools
There is no pool that pulls, so it was just dead code.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/4a05fe0c7a5c831389ef4aea51d24528ac8682c7.1577088521.git.luto@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-01-07 16:07:01 -05:00
Andy Lutomirski
90ea1c6436 random: remove the blocking pool
There is no longer any interface to read data from the blocking
pool, so remove it.

This enables quite a bit of code deletion, much of which will be
done in subsequent patches.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/511225a224bf0a291149d3c0b8b45393cd03ab96.1577088521.git.luto@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-01-07 16:07:01 -05:00
Andy Lutomirski
30c08efec8 random: make /dev/random be almost like /dev/urandom
This patch changes the read semantics of /dev/random to be the same
as /dev/urandom except that reads will block until the CRNG is
ready.

None of the cleanups that this enables have been done yet.  As a
result, this gives a warning about an unused function.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/5e6ac8831c6cf2e56a7a4b39616d1732b2bdd06c.1577088521.git.luto@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-01-07 16:07:01 -05:00
Andy Lutomirski
48446f198f random: ignore GRND_RANDOM in getentropy(2)
The separate blocking pool is going away.  Start by ignoring
GRND_RANDOM in getentropy(2).

This should not materially break any API.  Any code that worked
without this change should work at least as well with this change.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/705c5a091b63cc5da70c99304bb97e0109be0a26.1577088521.git.luto@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-01-07 16:07:01 -05:00
Andy Lutomirski
75551dbf11 random: add GRND_INSECURE to return best-effort non-cryptographic bytes
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/d5473b56cf1fa900ca4bd2b3fc1e5b8874399919.1577088521.git.luto@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-01-07 16:07:00 -05:00
Andy Lutomirski
c6f1deb158 random: Add a urandom_read_nowait() for random APIs that don't warn
/dev/random and getrandom() never warn.  Split the meat of
urandom_read() into urandom_read_nowarn() and leave the warning code
in urandom_read().

This has no effect on kernel behavior, but it makes subsequent
patches more straightforward.  It also makes the fact that
getrandom() never warns more obvious.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/c87ab200588de746431d9f916501ef11e5242b13.1577088521.git.luto@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-01-07 16:07:00 -05:00
Andy Lutomirski
4c8d062186 random: Don't wake crng_init_wait when crng_init == 1
crng_init_wait is only used to wayt for crng_init to be set to 2, so
there's no point to waking it when crng_init is set to 1.  Remove the
unnecessary wake_up_interruptible() call.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/6fbc0bfcbfc1fa2c76fd574f5b6f552b11be7fde.1577088521.git.luto@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-01-07 16:07:00 -05:00
Sergey Senozhatsky
1b710b1b10 char/random: silence a lockdep splat with printk()
Sergey didn't like the locking order,

uart_port->lock  ->  tty_port->lock

uart_write (uart_port->lock)
  __uart_start
    pl011_start_tx
      pl011_tx_chars
        uart_write_wakeup
          tty_port_tty_wakeup
            tty_port_default
              tty_port_tty_get (tty_port->lock)

but those code is so old, and I have no clue how to de-couple it after
checking other locks in the splat. There is an onging effort to make all
printk() as deferred, so until that happens, workaround it for now as a
short-term fix.

LTP: starting iogen01 (export LTPROOT; rwtest -N iogen01 -i 120s -s
read,write -Da -Dv -n 2 500b:$TMPDIR/doio.f1.$$
1000b:$TMPDIR/doio.f2.$$)
WARNING: possible circular locking dependency detected
------------------------------------------------------
doio/49441 is trying to acquire lock:
ffff008b7cff7290 (&(&zone->lock)->rlock){..-.}, at: rmqueue+0x138/0x2050

but task is already holding lock:
60ff000822352818 (&pool->lock/1){-.-.}, at: start_flush_work+0xd8/0x3f0

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> #4 (&pool->lock/1){-.-.}:
       lock_acquire+0x320/0x360
       _raw_spin_lock+0x64/0x80
       __queue_work+0x4b4/0xa10
       queue_work_on+0xac/0x11c
       tty_schedule_flip+0x84/0xbc
       tty_flip_buffer_push+0x1c/0x28
       pty_write+0x98/0xd0
       n_tty_write+0x450/0x60c
       tty_write+0x338/0x474
       __vfs_write+0x88/0x214
       vfs_write+0x12c/0x1a4
       redirected_tty_write+0x90/0xdc
       do_loop_readv_writev+0x140/0x180
       do_iter_write+0xe0/0x10c
       vfs_writev+0x134/0x1cc
       do_writev+0xbc/0x130
       __arm64_sys_writev+0x58/0x8c
       el0_svc_handler+0x170/0x240
       el0_sync_handler+0x150/0x250
       el0_sync+0x164/0x180

  -> #3 (&(&port->lock)->rlock){-.-.}:
       lock_acquire+0x320/0x360
       _raw_spin_lock_irqsave+0x7c/0x9c
       tty_port_tty_get+0x24/0x60
       tty_port_default_wakeup+0x1c/0x3c
       tty_port_tty_wakeup+0x34/0x40
       uart_write_wakeup+0x28/0x44
       pl011_tx_chars+0x1b8/0x270
       pl011_start_tx+0x24/0x70
       __uart_start+0x5c/0x68
       uart_write+0x164/0x1c8
       do_output_char+0x33c/0x348
       n_tty_write+0x4bc/0x60c
       tty_write+0x338/0x474
       redirected_tty_write+0xc0/0xdc
       do_loop_readv_writev+0x140/0x180
       do_iter_write+0xe0/0x10c
       vfs_writev+0x134/0x1cc
       do_writev+0xbc/0x130
       __arm64_sys_writev+0x58/0x8c
       el0_svc_handler+0x170/0x240
       el0_sync_handler+0x150/0x250
       el0_sync+0x164/0x180

  -> #2 (&port_lock_key){-.-.}:
       lock_acquire+0x320/0x360
       _raw_spin_lock+0x64/0x80
       pl011_console_write+0xec/0x2cc
       console_unlock+0x794/0x96c
       vprintk_emit+0x260/0x31c
       vprintk_default+0x54/0x7c
       vprintk_func+0x218/0x254
       printk+0x7c/0xa4
       register_console+0x734/0x7b0
       uart_add_one_port+0x734/0x834
       pl011_register_port+0x6c/0xac
       sbsa_uart_probe+0x234/0x2ec
       platform_drv_probe+0xd4/0x124
       really_probe+0x250/0x71c
       driver_probe_device+0xb4/0x200
       __device_attach_driver+0xd8/0x188
       bus_for_each_drv+0xbc/0x110
       __device_attach+0x120/0x220
       device_initial_probe+0x20/0x2c
       bus_probe_device+0x54/0x100
       device_add+0xae8/0xc2c
       platform_device_add+0x278/0x3b8
       platform_device_register_full+0x238/0x2ac
       acpi_create_platform_device+0x2dc/0x3a8
       acpi_bus_attach+0x390/0x3cc
       acpi_bus_attach+0x108/0x3cc
       acpi_bus_attach+0x108/0x3cc
       acpi_bus_attach+0x108/0x3cc
       acpi_bus_scan+0x7c/0xb0
       acpi_scan_init+0xe4/0x304
       acpi_init+0x100/0x114
       do_one_initcall+0x348/0x6a0
       do_initcall_level+0x190/0x1fc
       do_basic_setup+0x34/0x4c
       kernel_init_freeable+0x19c/0x260
       kernel_init+0x18/0x338
       ret_from_fork+0x10/0x18

  -> #1 (console_owner){-...}:
       lock_acquire+0x320/0x360
       console_lock_spinning_enable+0x6c/0x7c
       console_unlock+0x4f8/0x96c
       vprintk_emit+0x260/0x31c
       vprintk_default+0x54/0x7c
       vprintk_func+0x218/0x254
       printk+0x7c/0xa4
       get_random_u64+0x1c4/0x1dc
       shuffle_pick_tail+0x40/0xac
       __free_one_page+0x424/0x710
       free_one_page+0x70/0x120
       __free_pages_ok+0x61c/0xa94
       __free_pages_core+0x1bc/0x294
       memblock_free_pages+0x38/0x48
       __free_pages_memory+0xcc/0xfc
       __free_memory_core+0x70/0x78
       free_low_memory_core_early+0x148/0x18c
       memblock_free_all+0x18/0x54
       mem_init+0xb4/0x17c
       mm_init+0x14/0x38
       start_kernel+0x19c/0x530

  -> #0 (&(&zone->lock)->rlock){..-.}:
       validate_chain+0xf6c/0x2e2c
       __lock_acquire+0x868/0xc2c
       lock_acquire+0x320/0x360
       _raw_spin_lock+0x64/0x80
       rmqueue+0x138/0x2050
       get_page_from_freelist+0x474/0x688
       __alloc_pages_nodemask+0x3b4/0x18dc
       alloc_pages_current+0xd0/0xe0
       alloc_slab_page+0x2b4/0x5e0
       new_slab+0xc8/0x6bc
       ___slab_alloc+0x3b8/0x640
       kmem_cache_alloc+0x4b4/0x588
       __debug_object_init+0x778/0x8b4
       debug_object_init_on_stack+0x40/0x50
       start_flush_work+0x16c/0x3f0
       __flush_work+0xb8/0x124
       flush_work+0x20/0x30
       xlog_cil_force_lsn+0x88/0x204 [xfs]
       xfs_log_force_lsn+0x128/0x1b8 [xfs]
       xfs_file_fsync+0x3c4/0x488 [xfs]
       vfs_fsync_range+0xb0/0xd0
       generic_write_sync+0x80/0xa0 [xfs]
       xfs_file_buffered_aio_write+0x66c/0x6e4 [xfs]
       xfs_file_write_iter+0x1a0/0x218 [xfs]
       __vfs_write+0x1cc/0x214
       vfs_write+0x12c/0x1a4
       ksys_write+0xb0/0x120
       __arm64_sys_write+0x54/0x88
       el0_svc_handler+0x170/0x240
       el0_sync_handler+0x150/0x250
       el0_sync+0x164/0x180

       other info that might help us debug this:

 Chain exists of:
   &(&zone->lock)->rlock --> &(&port->lock)->rlock --> &pool->lock/1

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&pool->lock/1);
                               lock(&(&port->lock)->rlock);
                               lock(&pool->lock/1);
  lock(&(&zone->lock)->rlock);

                *** DEADLOCK ***

4 locks held by doio/49441:
 #0: a0ff00886fc27408 (sb_writers#8){.+.+}, at: vfs_write+0x118/0x1a4
 #1: 8fff00080810dfe0 (&xfs_nondir_ilock_class){++++}, at:
xfs_ilock+0x2a8/0x300 [xfs]
 #2: ffff9000129f2390 (rcu_read_lock){....}, at:
rcu_lock_acquire+0x8/0x38
 #3: 60ff000822352818 (&pool->lock/1){-.-.}, at:
start_flush_work+0xd8/0x3f0

               stack backtrace:
CPU: 48 PID: 49441 Comm: doio Tainted: G        W
Hardware name: HPE Apollo 70             /C01_APACHE_MB         , BIOS
L50_5.13_1.11 06/18/2019
Call trace:
 dump_backtrace+0x0/0x248
 show_stack+0x20/0x2c
 dump_stack+0xe8/0x150
 print_circular_bug+0x368/0x380
 check_noncircular+0x28c/0x294
 validate_chain+0xf6c/0x2e2c
 __lock_acquire+0x868/0xc2c
 lock_acquire+0x320/0x360
 _raw_spin_lock+0x64/0x80
 rmqueue+0x138/0x2050
 get_page_from_freelist+0x474/0x688
 __alloc_pages_nodemask+0x3b4/0x18dc
 alloc_pages_current+0xd0/0xe0
 alloc_slab_page+0x2b4/0x5e0
 new_slab+0xc8/0x6bc
 ___slab_alloc+0x3b8/0x640
 kmem_cache_alloc+0x4b4/0x588
 __debug_object_init+0x778/0x8b4
 debug_object_init_on_stack+0x40/0x50
 start_flush_work+0x16c/0x3f0
 __flush_work+0xb8/0x124
 flush_work+0x20/0x30
 xlog_cil_force_lsn+0x88/0x204 [xfs]
 xfs_log_force_lsn+0x128/0x1b8 [xfs]
 xfs_file_fsync+0x3c4/0x488 [xfs]
 vfs_fsync_range+0xb0/0xd0
 generic_write_sync+0x80/0xa0 [xfs]
 xfs_file_buffered_aio_write+0x66c/0x6e4 [xfs]
 xfs_file_write_iter+0x1a0/0x218 [xfs]
 __vfs_write+0x1cc/0x214
 vfs_write+0x12c/0x1a4
 ksys_write+0xb0/0x120
 __arm64_sys_write+0x54/0x88
 el0_svc_handler+0x170/0x240
 el0_sync_handler+0x150/0x250
 el0_sync+0x164/0x180

Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Signed-off-by: Qian Cai <cai@lca.pw>
Link: https://lore.kernel.org/r/1573679785-21068-1-git-send-email-cai@lca.pw
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-01-07 16:07:00 -05:00
Jason A. Donenfeld
4aa37c4637 random: don't forget compat_ioctl on urandom
Recently, there's been some compat ioctl cleanup, in which large
hardcoded lists were replaced with compat_ptr_ioctl. One of these
changes involved removing the random.c hardcoded list entries and adding
a compat ioctl function pointer to the random.c fops. In the process,
urandom was forgotten about, so this commit fixes that oversight.

Fixes: 507e4e2b43 ("compat_ioctl: remove /dev/random commands")
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Link: https://lore.kernel.org/r/20191217172455.186395-1-Jason@zx2c4.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-17 19:19:24 +01:00
Linus Torvalds
0da522107e compat_ioctl: remove most of fs/compat_ioctl.c
As part of the cleanup of some remaining y2038 issues, I came to
 fs/compat_ioctl.c, which still has a couple of commands that need support
 for time64_t.
 
 In completely unrelated work, I spent time on cleaning up parts of this
 file in the past, moving things out into drivers instead.
 
 After Al Viro reviewed an earlier version of this series and did a lot
 more of that cleanup, I decided to try to completely eliminate the rest
 of it and move it all into drivers.
 
 This series incorporates some of Al's work and many patches of my own,
 but in the end stops short of actually removing the last part, which is
 the scsi ioctl handlers. I have patches for those as well, but they need
 more testing or possibly a rewrite.
 
 Signed-off-by: Arnd Bergmann <arnd@arndb.de>
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2
 
 iQIcBAABCAAGBQJdsHCdAAoJEJpsee/mABjZtYkP/1JGl3jFv3Iq/5BCdPkaePP1
 RtMJRNfURgK3GeuHUui330PvVjI/pLWXU/VXMK2MPTASpJLzYz3uCaZrpVWEMpDZ
 +ImzGmgJkITlW1uWU3zOcQhOxTyb1hCZ0Ci+2xn9QAmyOL7prXoXCXDWv3h6iyiF
 lwG+nW+HNtyx41YG+9bRfKNoG0ZJ+nkJ70BV6u0acQHXWn7Xuupa9YUmBL87hxAL
 6dlJfLTJg6q8QSv/Q6LxslfWk2Ti8OOJZOwtFM5R8Bgl0iUcvshiRCKfv/3t9jXD
 dJNvF1uq8z+gracWK49Qsfq5dnZ2ZxHFUo9u0NjbCrxNvWH/sdvhbaUBuJI75seH
 VIznCkdxFhrqitJJ8KmxANxG08u+9zSKjSlxG2SmlA4qFx/AoStoHwQXcogJscNb
 YIXYKmWBvwPzYu09QFAXdHFPmZvp/3HhMWU6o92lvDhsDwzkSGt3XKhCJea4DCaT
 m+oCcoACqSWhMwdbJOEFofSub4bY43s5iaYuKes+c8O261/Dwg6v/pgIVez9mxXm
 TBnvCsotq5m8wbwzv99eFqGeJH8zpDHrXxEtRR5KQqMqjLq/OQVaEzmpHZTEuK7n
 e/V/PAKo2/V63g4k6GApQXDxnjwT+m0aWToWoeEzPYXS6KmtWC91r4bWtslu3rdl
 bN65armTm7bFFR32Avnu
 =lgCl
 -----END PGP SIGNATURE-----

Merge tag 'compat-ioctl-5.5' of git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground

Pull removal of most of fs/compat_ioctl.c from Arnd Bergmann:
 "As part of the cleanup of some remaining y2038 issues, I came to
  fs/compat_ioctl.c, which still has a couple of commands that need
  support for time64_t.

  In completely unrelated work, I spent time on cleaning up parts of
  this file in the past, moving things out into drivers instead.

  After Al Viro reviewed an earlier version of this series and did a lot
  more of that cleanup, I decided to try to completely eliminate the
  rest of it and move it all into drivers.

  This series incorporates some of Al's work and many patches of my own,
  but in the end stops short of actually removing the last part, which
  is the scsi ioctl handlers. I have patches for those as well, but they
  need more testing or possibly a rewrite"

* tag 'compat-ioctl-5.5' of git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground: (42 commits)
  scsi: sd: enable compat ioctls for sed-opal
  pktcdvd: add compat_ioctl handler
  compat_ioctl: move SG_GET_REQUEST_TABLE handling
  compat_ioctl: ppp: move simple commands into ppp_generic.c
  compat_ioctl: handle PPPIOCGIDLE for 64-bit time_t
  compat_ioctl: move PPPIOCSCOMPRESS to ppp_generic
  compat_ioctl: unify copy-in of ppp filters
  tty: handle compat PPP ioctls
  compat_ioctl: move SIOCOUTQ out of compat_ioctl.c
  compat_ioctl: handle SIOCOUTQNSD
  af_unix: add compat_ioctl support
  compat_ioctl: reimplement SG_IO handling
  compat_ioctl: move WDIOC handling into wdt drivers
  fs: compat_ioctl: move FITRIM emulation into file systems
  gfs2: add compat_ioctl support
  compat_ioctl: remove unused convert_in_user macro
  compat_ioctl: remove last RAID handling code
  compat_ioctl: remove /dev/raw ioctl translation
  compat_ioctl: remove PCI ioctl translation
  compat_ioctl: remove joystick ioctl translation
  ...
2019-12-01 13:46:15 -08:00
Linus Torvalds
1d4c79ed32 Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto fix from Herbert Xu:
 "This reverts a number of changes to the khwrng thread which feeds the
  kernel random number pool from hwrng drivers. They were trying to fix
  issues with suspend-and-resume but ended up causing regressions"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  Revert "hwrng: core - Freeze khwrng thread during suspend"
2019-11-16 18:14:32 -08:00
Herbert Xu
08e97aec70 Revert "hwrng: core - Freeze khwrng thread during suspend"
This reverts commit 03a3bb7ae6 ("hwrng: core - Freeze khwrng
thread during suspend"), ff296293b3 ("random: Support freezable
kthreads in add_hwgenerator_randomness()") and 59b569480d ("random:
Use wait_event_freezable() in add_hwgenerator_randomness()").

These patches introduced regressions and we need more time to
get them ready for mainline.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-11-17 08:48:17 +08:00
Arnd Bergmann
507e4e2b43 compat_ioctl: remove /dev/random commands
These are all handled by the random driver, so instead of listing
each ioctl, we can use the generic compat_ptr_ioctl() helper.

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-10-23 17:23:45 +02:00
Borislav Petkov
3fd57e7a9e char/random: Add a newline at the end of the file
On Tue, Oct 01, 2019 at 10:14:40AM -0700, Linus Torvalds wrote:
> The previous state of the file didn't have that 0xa at the end, so you get that
>
>
>   -EXPORT_SYMBOL_GPL(add_bootloader_randomness);
>   \ No newline at end of file
>   +EXPORT_SYMBOL_GPL(add_bootloader_randomness);
>
> which is "the '-' line doesn't have a newline, the '+' line does" marker.

Aaha, that makes total sense, thanks for explaining. Oh well, let's fix
it then so that people don't scratch heads like me.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-10-02 13:49:43 -07:00
Linus Torvalds
3f2dc2798b Merge branch 'entropy'
Merge active entropy generation updates.

This is admittedly partly "for discussion".  We need to have a way
forward for the boot time deadlocks where user space ends up waiting for
more entropy, but no entropy is forthcoming because the system is
entirely idle just waiting for something to happen.

While this was triggered by what is arguably a user space bug with
GDM/gnome-session asking for secure randomness during early boot, when
they didn't even need any such truly secure thing, the issue ends up
being that our "getrandom()" interface is prone to that kind of
confusion, because people don't think very hard about whether they want
to block for sufficient amounts of entropy.

The approach here-in is to decide to not just passively wait for entropy
to happen, but to start actively collecting it if it is missing.  This
is not necessarily always possible, but if the architecture has a CPU
cycle counter, there is a fair amount of noise in the exact timings of
reasonably complex loads.

We may end up tweaking the load and the entropy estimates, but this
should be at least a reasonable starting point.

As part of this, we also revert the revert of the ext4 IO pattern
improvement that ended up triggering the reported lack of external
entropy.

* getrandom() active entropy waiting:
  Revert "Revert "ext4: make __ext4_get_inode_loc plug""
  random: try to actively add entropy rather than passively wait for it
2019-09-29 19:25:39 -07:00
Linus Torvalds
50ee7529ec random: try to actively add entropy rather than passively wait for it
For 5.3 we had to revert a nice ext4 IO pattern improvement, because it
caused a bootup regression due to lack of entropy at bootup together
with arguably broken user space that was asking for secure random
numbers when it really didn't need to.

See commit 72dbcf7215 (Revert "ext4: make __ext4_get_inode_loc plug").

This aims to solve the issue by actively generating entropy noise using
the CPU cycle counter when waiting for the random number generator to
initialize.  This only works when you have a high-frequency time stamp
counter available, but that's the case on all modern x86 CPU's, and on
most other modern CPU's too.

What we do is to generate jitter entropy from the CPU cycle counter
under a somewhat complex load: calling the scheduler while also
guaranteeing a certain amount of timing noise by also triggering a
timer.

I'm sure we can tweak this, and that people will want to look at other
alternatives, but there's been a number of papers written on jitter
entropy, and this should really be fairly conservative by crediting one
bit of entropy for every timer-induced jump in the cycle counter.  Not
because the timer itself would be all that unpredictable, but because
the interaction between the timer and the loop is going to be.

Even if (and perhaps particularly if) the timer actually happens on
another CPU, the cacheline interaction between the loop that reads the
cycle counter and the timer itself firing is going to add perturbations
to the cycle counter values that get mixed into the entropy pool.

As Thomas pointed out, with a modern out-of-order CPU, even quite simple
loops show a fair amount of hard-to-predict timing variability even in
the absense of external interrupts.  But this tries to take that further
by actually having a fairly complex interaction.

This is not going to solve the entropy issue for architectures that have
no CPU cycle counter, but it's not clear how (and if) that is solvable,
and the hardware in question is largely starting to be irrelevant.  And
by doing this we can at least avoid some of the even more contentious
approaches (like making the entropy waiting time out in order to avoid
the possibly unbounded waiting).

Cc: Ahmed Darwish <darwish.07@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Nicholas Mc Guire <hofrat@opentech.at>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Alexander E. Patrakov <patrakov@gmail.com>
Cc: Lennart Poettering <mzxreary@0pointer.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-29 17:38:52 -07:00
Linus Torvalds
8b53c76533 Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto updates from Herbert Xu:
 "API:
   - Add the ability to abort a skcipher walk.

  Algorithms:
   - Fix XTS to actually do the stealing.
   - Add library helpers for AES and DES for single-block users.
   - Add library helpers for SHA256.
   - Add new DES key verification helper.
   - Add surrounding bits for ESSIV generator.
   - Add accelerations for aegis128.
   - Add test vectors for lzo-rle.

  Drivers:
   - Add i.MX8MQ support to caam.
   - Add gcm/ccm/cfb/ofb aes support in inside-secure.
   - Add ofb/cfb aes support in media-tek.
   - Add HiSilicon ZIP accelerator support.

  Others:
   - Fix potential race condition in padata.
   - Use unbound workqueues in padata"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (311 commits)
  crypto: caam - Cast to long first before pointer conversion
  crypto: ccree - enable CTS support in AES-XTS
  crypto: inside-secure - Probe transform record cache RAM sizes
  crypto: inside-secure - Base RD fetchcount on actual RD FIFO size
  crypto: inside-secure - Base CD fetchcount on actual CD FIFO size
  crypto: inside-secure - Enable extended algorithms on newer HW
  crypto: inside-secure: Corrected configuration of EIP96_TOKEN_CTRL
  crypto: inside-secure - Add EIP97/EIP197 and endianness detection
  padata: remove cpu_index from the parallel_queue
  padata: unbind parallel jobs from specific CPUs
  padata: use separate workqueues for parallel and serial work
  padata, pcrypt: take CPU hotplug lock internally in padata_alloc_possible
  crypto: pcrypt - remove padata cpumask notifier
  padata: make padata_do_parallel find alternate callback CPU
  workqueue: require CPU hotplug read exclusion for apply_workqueue_attrs
  workqueue: unconfine alloc/apply/free_workqueue_attrs()
  padata: allocate workqueue internally
  arm64: dts: imx8mq: Add CAAM node
  random: Use wait_event_freezable() in add_hwgenerator_randomness()
  crypto: ux500 - Fix COMPILE_TEST warnings
  ...
2019-09-18 12:11:14 -07:00
Stephen Boyd
59b569480d random: Use wait_event_freezable() in add_hwgenerator_randomness()
Sebastian reports that after commit ff296293b3 ("random: Support freezable
kthreads in add_hwgenerator_randomness()") we can call might_sleep() when the
task state is TASK_INTERRUPTIBLE (state=1). This leads to the following warning.

 do not call blocking ops when !TASK_RUNNING; state=1 set at [<00000000349d1489>] prepare_to_wait_event+0x5a/0x180
 WARNING: CPU: 0 PID: 828 at kernel/sched/core.c:6741 __might_sleep+0x6f/0x80
 Modules linked in:

 CPU: 0 PID: 828 Comm: hwrng Not tainted 5.3.0-rc7-next-20190903+ #46
 RIP: 0010:__might_sleep+0x6f/0x80

 Call Trace:
  kthread_freezable_should_stop+0x1b/0x60
  add_hwgenerator_randomness+0xdd/0x130
  hwrng_fillfn+0xbf/0x120
  kthread+0x10c/0x140
  ret_from_fork+0x27/0x50

We shouldn't call kthread_freezable_should_stop() from deep within the
wait_event code because the task state is still set as
TASK_INTERRUPTIBLE instead of TASK_RUNNING and
kthread_freezable_should_stop() will try to call into the freezer with
the task in the wrong state. Use wait_event_freezable() instead so that
it calls schedule() in the right place and tries to enter the freezer
when the task state is TASK_RUNNING instead.

Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Keerthy <j-keerthy@ti.com>
Fixes: ff296293b3 ("random: Support freezable kthreads in add_hwgenerator_randomness()")
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-09-09 23:48:41 +10:00
Hsin-Yi Wang
428826f535 fdt: add support for rng-seed
Introducing a chosen node, rng-seed, which is an entropy that can be
passed to kernel called very early to increase initial device
randomness. Bootloader should provide this entropy and the value is
read from /chosen/rng-seed in DT.

Obtain of_fdt_crc32 for CRC check after early_init_dt_scan_nodes(),
since early_init_dt_scan_chosen() would modify fdt to erase rng-seed.

Add a new interface add_bootloader_randomness() for rng-seed use case.
Depends on whether the seed is trustworthy, rng seed would be passed to
add_hwgenerator_randomness(). Otherwise it would be passed to
add_device_randomness(). Decision is controlled by kernel config
RANDOM_TRUST_BOOTLOADER.

Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Theodore Ts'o <tytso@mit.edu> # drivers/char/random.c
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-23 16:39:26 +01:00
Stephen Boyd
ff296293b3 random: Support freezable kthreads in add_hwgenerator_randomness()
The kthread calling this function is freezable after commit 03a3bb7ae6
("hwrng: core - Freeze khwrng thread during suspend") is applied.
Unfortunately, this function uses wait_event_interruptible() but doesn't
check for the kthread being woken up by the fake freezer signal. When a
user suspends the system, this kthread will wake up and if it fails the
entropy size check it will immediately go back to sleep and not go into
the freezer. Eventually, suspend will fail because the task never froze
and a warning message like this may appear:

 PM: suspend entry (deep)
 Filesystems sync: 0.000 seconds
 Freezing user space processes ... (elapsed 0.001 seconds) done.
 OOM killer disabled.
 Freezing remaining freezable tasks ...
 Freezing of tasks failed after 20.003 seconds (1 tasks refusing to freeze, wq_busy=0):
 hwrng           R  running task        0   289      2 0x00000020
 [<c08c64c4>] (__schedule) from [<c08c6a10>] (schedule+0x3c/0xc0)
 [<c08c6a10>] (schedule) from [<c05dbd8c>] (add_hwgenerator_randomness+0xb0/0x100)
 [<c05dbd8c>] (add_hwgenerator_randomness) from [<bf1803c8>] (hwrng_fillfn+0xc0/0x14c [rng_core])
 [<bf1803c8>] (hwrng_fillfn [rng_core]) from [<c015abec>] (kthread+0x134/0x148)
 [<c015abec>] (kthread) from [<c01010e8>] (ret_from_fork+0x14/0x2c)

Check for a freezer signal here and skip adding any randomness if the
task wakes up because it was frozen. This should make the kthread freeze
properly and suspend work again.

Fixes: 03a3bb7ae6 ("hwrng: core - Freeze khwrng thread during suspend")
Reported-by: Keerthy <j-keerthy@ti.com>
Tested-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-08-22 14:39:36 +10:00
Theodore Ts'o
58be0106c5 random: fix soft lockup when trying to read from an uninitialized blocking pool
Fixes: eb9d1bf079: "random: only read from /dev/random after its pool has received 128 bits"
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2019-05-26 00:11:49 -04:00
Sebastian Andrzej Siewior
b7d5dc2107 random: add a spinlock_t to struct batched_entropy
The per-CPU variable batched_entropy_uXX is protected by get_cpu_var().
This is just a preempt_disable() which ensures that the variable is only
from the local CPU. It does not protect against users on the same CPU
from another context. It is possible that a preemptible context reads
slot 0 and then an interrupt occurs and the same value is read again.

The above scenario is confirmed by lockdep if we add a spinlock:
| ================================
| WARNING: inconsistent lock state
| 5.1.0-rc3+ #42 Not tainted
| --------------------------------
| inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
| ksoftirqd/9/56 [HC0[0]:SC1[1]:HE0:SE0] takes:
| (____ptrval____) (batched_entropy_u32.lock){+.?.}, at: get_random_u32+0x3e/0xe0
| {SOFTIRQ-ON-W} state was registered at:
|   _raw_spin_lock+0x2a/0x40
|   get_random_u32+0x3e/0xe0
|   new_slab+0x15c/0x7b0
|   ___slab_alloc+0x492/0x620
|   __slab_alloc.isra.73+0x53/0xa0
|   kmem_cache_alloc_node+0xaf/0x2a0
|   copy_process.part.41+0x1e1/0x2370
|   _do_fork+0xdb/0x6d0
|   kernel_thread+0x20/0x30
|   kthreadd+0x1ba/0x220
|   ret_from_fork+0x3a/0x50
…
| other info that might help us debug this:
|  Possible unsafe locking scenario:
|
|        CPU0
|        ----
|   lock(batched_entropy_u32.lock);
|   <Interrupt>
|     lock(batched_entropy_u32.lock);
|
|  *** DEADLOCK ***
|
| stack backtrace:
| Call Trace:
…
|  kmem_cache_alloc_trace+0x20e/0x270
|  ipmi_alloc_recv_msg+0x16/0x40
…
|  __do_softirq+0xec/0x48d
|  run_ksoftirqd+0x37/0x60
|  smpboot_thread_fn+0x191/0x290
|  kthread+0xfe/0x130
|  ret_from_fork+0x3a/0x50

Add a spinlock_t to the batched_entropy data structure and acquire the
lock while accessing it. Acquire the lock with disabled interrupts
because this function may be used from interrupt context.

Remove the batched_entropy_reset_lock lock. Now that we have a lock for
the data scructure, we can access it from a remote CPU.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2019-04-20 00:09:56 -04:00
George Spelvin
92e507d216 random: document get_random_int() family
Explain what these functions are for and when they offer
an advantage over get_random_bytes().

(We still need documentation on rng_is_initialized(), the
random_ready_callback system, and early boot in general.)

Signed-off-by: George Spelvin <lkml@sdf.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2019-04-19 23:48:25 -04:00
Jon DeVree
fe6f1a6a8e random: fix CRNG initialization when random.trust_cpu=1
When the system boots with random.trust_cpu=1 it doesn't initialize the
per-NUMA CRNGs because it skips the rest of the CRNG startup code. This
means that the code from 1e7f583af6 ("random: make /dev/urandom scalable
for silly userspace programs") is not used when random.trust_cpu=1.

crash> dmesg | grep random:
[    0.000000] random: get_random_bytes called from start_kernel+0x94/0x530 with crng_init=0
[    0.314029] random: crng done (trusting CPU's manufacturer)
crash> print crng_node_pool
$6 = (struct crng_state **) 0x0

After adding the missing call to numa_crng_init() the per-NUMA CRNGs are
initialized again:

crash> dmesg | grep random:
[    0.000000] random: get_random_bytes called from start_kernel+0x94/0x530 with crng_init=0
[    0.314031] random: crng done (trusting CPU's manufacturer)
crash> print crng_node_pool
$1 = (struct crng_state **) 0xffff9a915f4014a0

The call to invalidate_batched_entropy() was also missing. This is
important for architectures like PPC and S390 which only have the
arch_get_random_seed_* functions.

Fixes: 39a8883a2b ("random: add a config option to trust the CPU's hwrng")
Signed-off-by: Jon DeVree <nuxi@vault24.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2019-04-19 23:35:16 -04:00
Kees Cook
d55535232c random: move rand_initialize() earlier
Right now rand_initialize() is run as an early_initcall(), but it only
depends on timekeeping_init() (for mixing ktime_get_real() into the
pools). However, the call to boot_init_stack_canary() for stack canary
initialization runs earlier, which triggers a warning at boot:

random: get_random_bytes called from start_kernel+0x357/0x548 with crng_init=0

Instead, this moves rand_initialize() to after timekeeping_init(), and moves
canary initialization here as well.

Note that this warning may still remain for machines that do not have
UEFI RNG support (which initializes the RNG pools during setup_arch()),
or for x86 machines without RDRAND (or booting without "random.trust=on"
or CONFIG_RANDOM_TRUST_CPU=y).

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2019-04-19 23:27:05 -04:00
Theodore Ts'o
eb9d1bf079 random: only read from /dev/random after its pool has received 128 bits
Immediately after boot, we allow reads from /dev/random before its
entropy pool has been fully initialized.  Fix this so that we don't
allow this until the blocking pool has received 128 bits.

We do this by repurposing the initialized flag in the entropy pool
struct, and use the initialized flag in the blocking pool to indicate
whether it is safe to pull from the blocking pool.

To do this, we needed to rework when we decide to push entropy from the
input pool to the blocking pool, since the initialized flag for the
input pool was used for this purpose.  To simplify things, we no
longer use the initialized flag for that purpose, nor do we use the
entropy_total field any more.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2019-04-17 10:30:21 -04:00
Rasmus Villemoes
764ed189c8 drivers/char/random.c: make primary_crng static
Since the definition of struct crng_state is private to random.c, and
primary_crng is neither declared or used elsewhere, there's no reason
for that symbol to have external linkage.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2019-04-17 10:30:21 -04:00
Rasmus Villemoes
3bd0b5bf7d drivers/char/random.c: remove unused stuct poolinfo::poolbits
This field is never used, might as well remove it.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2019-04-17 10:30:21 -04:00
Rasmus Villemoes
26e0854ab3 drivers/char/random.c: constify poolinfo_table
Never modified, might as well be put in .rodata.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2019-04-17 10:30:21 -04:00
Eric Biggers
1ca1b91794 crypto: chacha20-generic - refactor to allow varying number of rounds
In preparation for adding XChaCha12 support, rename/refactor
chacha20-generic to support different numbers of rounds.  The
justification for needing XChaCha12 support is explained in more detail
in the patch "crypto: chacha - add XChaCha12 support".

The only difference between ChaCha{8,12,20} are the number of rounds
itself; all other parts of the algorithm are the same.  Therefore,
remove the "20" from all definitions, structures, functions, files, etc.
that will be shared by all ChaCha versions.

Also make ->setkey() store the round count in the chacha_ctx (previously
chacha20_ctx).  The generic code then passes the round count through to
chacha_block().  There will be a ->setkey() function for each explicitly
allowed round count; the encrypt/decrypt functions will be the same.  I
decided not to do it the opposite way (same ->setkey() function for all
round counts, with different encrypt/decrypt functions) because that
would have required more boilerplate code in architecture-specific
implementations of ChaCha and XChaCha.

Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Martin Willi <martin@strongswan.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-11-20 14:26:55 +08:00
Linus Torvalds
62606c224d Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto updates from Herbert Xu:
 "API:
   - Remove VLA usage
   - Add cryptostat user-space interface
   - Add notifier for new crypto algorithms

  Algorithms:
   - Add OFB mode
   - Remove speck

  Drivers:
   - Remove x86/sha*-mb as they are buggy
   - Remove pcbc(aes) from x86/aesni
   - Improve performance of arm/ghash-ce by up to 85%
   - Implement CTS-CBC in arm64/aes-blk, faster by up to 50%
   - Remove PMULL based arm64/crc32 driver
   - Use PMULL in arm64/crct10dif
   - Add aes-ctr support in s5p-sss
   - Add caam/qi2 driver

  Others:
   - Pick better transform if one becomes available in crc-t10dif"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (124 commits)
  crypto: chelsio - Update ntx queue received from cxgb4
  crypto: ccree - avoid implicit enum conversion
  crypto: caam - add SPDX license identifier to all files
  crypto: caam/qi - simplify CGR allocation, freeing
  crypto: mxs-dcp - make symbols 'sha1_null_hash' and 'sha256_null_hash' static
  crypto: arm64/aes-blk - ensure XTS mask is always loaded
  crypto: testmgr - fix sizeof() on COMP_BUF_SIZE
  crypto: chtls - remove set but not used variable 'csk'
  crypto: axis - fix platform_no_drv_owner.cocci warnings
  crypto: x86/aes-ni - fix build error following fpu template removal
  crypto: arm64/aes - fix handling sub-block CTS-CBC inputs
  crypto: caam/qi2 - avoid double export
  crypto: mxs-dcp - Fix AES issues
  crypto: mxs-dcp - Fix SHA null hashes and output length
  crypto: mxs-dcp - Implement sha import/export
  crypto: aegis/generic - fix for big endian systems
  crypto: morus/generic - fix for big endian systems
  crypto: lrw - fix rebase error after out of bounds fix
  crypto: cavium/nitrox - use pci_alloc_irq_vectors() while enabling MSI-X.
  crypto: cavium/nitrox - NITROX command queue changes.
  ...
2018-10-25 16:43:35 -07:00