<feed xmlns='http://www.w3.org/2005/Atom'>
<title>user/sven/linux.git/lib, branch v4.14.294</title>
<subtitle>Linux Kernel
</subtitle>
<id>https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v4.14.294</id>
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<updated>2022-09-05T08:25:04Z</updated>
<entry>
<title>ratelimit: Fix data-races in ___ratelimit().</title>
<updated>2022-09-05T08:25:04Z</updated>
<author>
<name>Kuniyuki Iwashima</name>
<email>kuniyu@amazon.com</email>
</author>
<published>2022-08-23T17:46:48Z</published>
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<id>urn:sha1:4cf771176d558f164a67e131b9d3f59e8570df8f</id>
<content type='text'>
[ Upstream commit 6bae8ceb90ba76cdba39496db936164fa672b9be ]

While reading rs-&gt;interval and rs-&gt;burst, they can be changed
concurrently via sysctl (e.g. net_ratelimit_state).  Thus, we
need to add READ_ONCE() to their readers.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima &lt;kuniyu@amazon.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>ida: don't use BUG_ON() for debugging</title>
<updated>2022-07-12T14:27:29Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-07-10T20:55:49Z</published>
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<id>urn:sha1:b91312b50751a1289fb2ec7ea6453a1961455cee</id>
<content type='text'>
commit fc82bbf4dede758007763867d0282353c06d1121 upstream.

This is another old BUG_ON() that just shouldn't exist (see also commit
a382f8fee42c: "signal handling: don't use BUG_ON() for debugging").

In fact, as Matthew Wilcox points out, this condition shouldn't really
even result in a warning, since a negative id allocation result is just
a normal allocation failure:

  "I wonder if we should even warn here -- sure, the caller is trying to
   free something that wasn't allocated, but we don't warn for
   kfree(NULL)"

and goes on to point out how that current error check is only causing
people to unnecessarily do their own index range checking before freeing
it.

This was noted by Itay Iellin, because the bluetooth HCI socket cookie
code does *not* do that range checking, and ends up just freeing the
error case too, triggering the BUG_ON().

The HCI code requires CAP_NET_RAW, and seems to just result in an ugly
splat, but there really is no reason to BUG_ON() here, and we have
generally striven for allocation models where it's always ok to just do

    free(alloc());

even if the allocation were to fail for some random reason (usually
obviously that "random" reason being some resource limit).

Fixes: 88eca0207cf1 ("ida: simplified functions for id allocation")
Reported-by: Itay Iellin &lt;ieitayie@gmail.com&gt;
Suggested-by: Matthew Wilcox &lt;willy@infradead.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>swiotlb: skip swiotlb_bounce when orig_addr is zero</title>
<updated>2022-07-02T14:18:11Z</updated>
<author>
<name>Liu Shixin</name>
<email>liushixin2@huawei.com</email>
</author>
<published>2022-06-30T11:32:25Z</published>
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<id>urn:sha1:87fe5447ea2d3331aeea4f225baa88179e9ab8a2</id>
<content type='text'>
After patch ddbd89deb7d3 ("swiotlb: fix info leak with DMA_FROM_DEVICE"),
swiotlb_bounce will be called in swiotlb_tbl_map_single unconditionally.
This requires that the physical address must be valid, which is not always
true on stable-4.19 or earlier version.
On stable-4.19, swiotlb_alloc_buffer will call swiotlb_tbl_map_single with
orig_addr equal to zero, which cause such a panic:

Unable to handle kernel paging request at virtual address ffffb77a40000000
...
pc : __memcpy+0x100/0x180
lr : swiotlb_bounce+0x74/0x88
...
Call trace:
 __memcpy+0x100/0x180
 swiotlb_tbl_map_single+0x2c8/0x338
 swiotlb_alloc+0xb4/0x198
 __dma_alloc+0x84/0x1d8
 ...

On stable-4.9 and stable-4.14, swiotlb_alloc_coherent wille call map_single
with orig_addr equal to zero, which can cause same panic.

Fix this by skipping swiotlb_bounce when orig_addr is zero.

Fixes: ddbd89deb7d3 ("swiotlb: fix info leak with DMA_FROM_DEVICE")
Signed-off-by: Liu Shixin &lt;liushixin2@huawei.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>random: remove ratelimiting for in-kernel unseeded randomness</title>
<updated>2022-06-25T09:46:40Z</updated>
<author>
<name>Jason A. Donenfeld</name>
<email>Jason@zx2c4.com</email>
</author>
<published>2022-05-09T14:13:18Z</published>
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<id>urn:sha1:319b965f9f19afc4421639a66de21f1818ceddde</id>
<content type='text'>
commit cc1e127bfa95b5fb2f9307e7168bf8b2b45b4c5e upstream.

The CONFIG_WARN_ALL_UNSEEDED_RANDOM debug option controls whether the
kernel warns about all unseeded randomness or just the first instance.
There's some complicated rate limiting and comparison to the previous
caller, such that even with CONFIG_WARN_ALL_UNSEEDED_RANDOM enabled,
developers still don't see all the messages or even an accurate count of
how many were missed. This is the result of basically parallel
mechanisms aimed at accomplishing more or less the same thing, added at
different points in random.c history, which sort of compete with the
first-instance-only limiting we have now.

It turns out, however, that nobody cares about the first unseeded
randomness instance of in-kernel users. The same first user has been
there for ages now, and nobody is doing anything about it. It isn't even
clear that anybody _can_ do anything about it. Most places that can do
something about it have switched over to using get_random_bytes_wait()
or wait_for_random_bytes(), which is the right thing to do, but there is
still much code that needs randomness sometimes during init, and as a
geeneral rule, if you're not using one of the _wait functions or the
readiness notifier callback, you're bound to be doing it wrong just
based on that fact alone.

So warning about this same first user that can't easily change is simply
not an effective mechanism for anything at all. Users can't do anything
about it, as the Kconfig text points out -- the problem isn't in
userspace code -- and kernel developers don't or more often can't react
to it.

Instead, show the warning for all instances when CONFIG_WARN_ALL_UNSEEDED_RANDOM
is set, so that developers can debug things need be, or if it isn't set,
don't show a warning at all.

At the same time, CONFIG_WARN_ALL_UNSEEDED_RANDOM now implies setting
random.ratelimit_disable=1 on by default, since if you care about one
you probably care about the other too. And we can clean up usage around
the related urandom_warning ratelimiter as well (whose behavior isn't
changing), so that it properly counts missed messages after the 10
message threshold is reached.

Cc: Theodore Ts'o &lt;tytso@mit.edu&gt;
Cc: Dominik Brodowski &lt;linux@dominikbrodowski.net&gt;
Signed-off-by: Jason A. Donenfeld &lt;Jason@zx2c4.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>siphash: use one source of truth for siphash permutations</title>
<updated>2022-06-25T09:46:39Z</updated>
<author>
<name>Jason A. Donenfeld</name>
<email>Jason@zx2c4.com</email>
</author>
<published>2022-05-07T12:03:46Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=66b2dde034bdc7bdb2de1b868deb0b3d5aa51a69'/>
<id>urn:sha1:66b2dde034bdc7bdb2de1b868deb0b3d5aa51a69</id>
<content type='text'>
commit e73aaae2fa9024832e1f42e30c787c7baf61d014 upstream.

The SipHash family of permutations is currently used in three places:

- siphash.c itself, used in the ordinary way it was intended.
- random32.c, in a construction from an anonymous contributor.
- random.c, as part of its fast_mix function.

Each one of these places reinvents the wheel with the same C code, same
rotation constants, and same symmetry-breaking constants.

This commit tidies things up a bit by placing macros for the
permutations and constants into siphash.h, where each of the three .c
users can access them. It also leaves a note dissuading more users of
them from emerging.

Signed-off-by: Jason A. Donenfeld &lt;Jason@zx2c4.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>random: replace custom notifier chain with standard one</title>
<updated>2022-06-25T09:46:36Z</updated>
<author>
<name>Jason A. Donenfeld</name>
<email>Jason@zx2c4.com</email>
</author>
<published>2022-03-01T19:03:49Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=c8e06a4dc297e6d96743e113bbf4804451e9927b'/>
<id>urn:sha1:c8e06a4dc297e6d96743e113bbf4804451e9927b</id>
<content type='text'>
commit 5acd35487dc911541672b3ffc322851769c32a56 upstream.

We previously rolled our own randomness readiness notifier, which only
has two users in the whole kernel. Replace this with a more standard
atomic notifier block that serves the same purpose with less code. Also
unexport the symbols, because no modules use it, only unconditional
builtins. The only drawback is that it's possible for a notification
handler returning the "stop" code to prevent further processing, but
given that there are only two users, and that we're unexporting this
anyway, that doesn't seem like a significant drawback for the
simplification we receive here.

Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: Theodore Ts'o &lt;tytso@mit.edu&gt;
Reviewed-by: Dominik Brodowski &lt;linux@dominikbrodowski.net&gt;
[Jason: for stable, also backported to crypto/drbg.c, not unexporting.]
Signed-off-by: Jason A. Donenfeld &lt;Jason@zx2c4.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>random: remove unused tracepoints</title>
<updated>2022-06-25T09:46:34Z</updated>
<author>
<name>Jason A. Donenfeld</name>
<email>Jason@zx2c4.com</email>
</author>
<published>2022-02-10T15:40:44Z</published>
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<id>urn:sha1:707c01fe19eb2128374d1a71b7b6d1c9ee2d379f</id>
<content type='text'>
commit 14c174633f349cb41ea90c2c0aaddac157012f74 upstream.

These explicit tracepoints aren't really used and show sign of aging.
It's work to keep these up to date, and before I attempted to keep them
up to date, they weren't up to date, which indicates that they're not
really used. These days there are better ways of introspecting anyway.

Cc: Theodore Ts'o &lt;tytso@mit.edu&gt;
Reviewed-by: Dominik Brodowski &lt;linux@dominikbrodowski.net&gt;
Reviewed-by: Eric Biggers &lt;ebiggers@google.com&gt;
Signed-off-by: Jason A. Donenfeld &lt;Jason@zx2c4.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>crypto: chacha20 - Fix chacha20_block() keystream alignment (again)</title>
<updated>2022-06-25T09:46:31Z</updated>
<author>
<name>Eric Biggers</name>
<email>ebiggers@google.com</email>
</author>
<published>2018-09-12T03:05:10Z</published>
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<id>urn:sha1:91393740d75fde2fa9bd329ea1f2723f90c5f26d</id>
<content type='text'>
[ Upstream commit a5e9f557098e54af44ade5d501379be18435bfbf ]

In commit 9f480faec58c ("crypto: chacha20 - Fix keystream alignment for
chacha20_block()"), I had missed that chacha20_block() can be called
directly on the buffer passed to get_random_bytes(), which can have any
alignment.  So, while my commit didn't break anything, it didn't fully
solve the alignment problems.

Revert my solution and just update chacha20_block() to use
put_unaligned_le32(), so the output buffer need not be aligned.
This is simpler, and on many CPUs it's the same speed.

But, I kept the 'tmp' buffers in extract_crng_user() and
_get_random_bytes() 4-byte aligned, since that alignment is actually
needed for _crng_backtrack_protect() too.

Reported-by: Stephan Müller &lt;smueller@chronox.de&gt;
Cc: Theodore Ts'o &lt;tytso@mit.edu&gt;
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>lib/crypto: sha1: re-roll loops to reduce code size</title>
<updated>2022-06-25T09:46:27Z</updated>
<author>
<name>Jason A. Donenfeld</name>
<email>Jason@zx2c4.com</email>
</author>
<published>2022-01-11T17:58:43Z</published>
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<id>urn:sha1:42b10f6770ed1e41c1021a4f9b477468f7ff6859</id>
<content type='text'>
commit 9a1536b093bb5bf60689021275fd24d513bb8db0 upstream.

With SHA-1 no longer being used for anything performance oriented, and
also soon to be phased out entirely, we can make up for the space added
by unrolled BLAKE2s by simply re-rolling SHA-1. Since SHA-1 is so much
more complex, re-rolling it more or less takes care of the code size
added by BLAKE2s. And eventually, hopefully we'll see SHA-1 removed
entirely from most small kernel builds.

Cc: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
Cc: Ard Biesheuvel &lt;ardb@kernel.org&gt;
Tested-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Signed-off-by: Jason A. Donenfeld &lt;Jason@zx2c4.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>lib/crypto: blake2s: move hmac construction into wireguard</title>
<updated>2022-06-25T09:46:27Z</updated>
<author>
<name>Jason A. Donenfeld</name>
<email>Jason@zx2c4.com</email>
</author>
<published>2022-01-11T13:37:41Z</published>
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<id>urn:sha1:66680715fd7b069dc6cd113c77e10311afe04276</id>
<content type='text'>
commit d8d83d8ab0a453e17e68b3a3bed1f940c34b8646 upstream.

Basically nobody should use blake2s in an HMAC construction; it already
has a keyed variant. But unfortunately for historical reasons, Noise,
used by WireGuard, uses HKDF quite strictly, which means we have to use
this. Because this really shouldn't be used by others, this commit moves
it into wireguard's noise.c locally, so that kernels that aren't using
WireGuard don't get this superfluous code baked in. On m68k systems,
this shaves off ~314 bytes.

Cc: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
Tested-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Acked-by: Ard Biesheuvel &lt;ardb@kernel.org&gt;
[Jason: for stable, skip the wireguard changes, since this kernel
 doesn't have wireguard.]
Signed-off-by: Jason A. Donenfeld &lt;Jason@zx2c4.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
</feed>
