kernel/linux.git/lib, branch v5.15.45

lib/crypto: add prompts back to crypto libraries

2022-06-06T06:43:37+00:00

commit e56e18985596617ae426ed5997fb2e737cffb58b upstream. Commit 6048fdcc5f269 ("lib/crypto: blake2s: include as built-in") took away a number of prompt texts from other crypto libraries. This makes values flip from built-in to module when oldconfig runs, and causes problems when these crypto libs need to be built in for thingslike BIG_KEYS. Fixes: 6048fdcc5f269 ("lib/crypto: blake2s: include as built-in") Cc: Herbert Xu Cc: linux-crypto@vger.kernel.org Signed-off-by: Justin M. Forbes [Jason: - moved menu into submenu of lib/ instead of root menu - fixed chacha sub-dependencies for CONFIG_CRYPTO] Signed-off-by: Jason A. Donenfeld Signed-off-by: Greg Kroah-Hartman

assoc_array: Fix BUG_ON during garbage collect

2022-06-06T06:43:37+00:00

commit d1dc87763f406d4e67caf16dbe438a5647692395 upstream. A rare BUG_ON triggered in assoc_array_gc: [3430308.818153] kernel BUG at lib/assoc_array.c:1609! Which corresponded to the statement currently at line 1593 upstream: BUG_ON(assoc_array_ptr_is_meta(p)); Using the data from the core dump, I was able to generate a userspace reproducer[1] and determine the cause of the bug. [1]: https://github.com/brenns10/kernel_stuff/tree/master/assoc_array_gc After running the iterator on the entire branch, an internal tree node looked like the following: NODE (nr_leaves_on_branch: 3) SLOT [0] NODE (2 leaves) SLOT [1] NODE (1 leaf) SLOT [2..f] NODE (empty) In the userspace reproducer, the pr_devel output when compressing this node was: -- compress node 0x5607cc089380 -- free=0, leaves=0 [0] retain node 2/1 [nx 0] [1] fold node 1/1 [nx 0] [2] fold node 0/1 [nx 2] [3] fold node 0/2 [nx 2] [4] fold node 0/3 [nx 2] [5] fold node 0/4 [nx 2] [6] fold node 0/5 [nx 2] [7] fold node 0/6 [nx 2] [8] fold node 0/7 [nx 2] [9] fold node 0/8 [nx 2] [10] fold node 0/9 [nx 2] [11] fold node 0/10 [nx 2] [12] fold node 0/11 [nx 2] [13] fold node 0/12 [nx 2] [14] fold node 0/13 [nx 2] [15] fold node 0/14 [nx 2] after: 3 At slot 0, an internal node with 2 leaves could not be folded into the node, because there was only one available slot (slot 0). Thus, the internal node was retained. At slot 1, the node had one leaf, and was able to be folded in successfully. The remaining nodes had no leaves, and so were removed. By the end of the compression stage, there were 14 free slots, and only 3 leaf nodes. The tree was ascended and then its parent node was compressed. When this node was seen, it could not be folded, due to the internal node it contained. The invariant for compression in this function is: whenever nr_leaves_on_branch < ASSOC_ARRAY_FAN_OUT, the node should contain all leaf nodes. The compression step currently cannot guarantee this, given the corner case shown above. To fix this issue, retry compression whenever we have retained a node, and yet nr_leaves_on_branch < ASSOC_ARRAY_FAN_OUT. This second compression will then allow the node in slot 1 to be folded in, satisfying the invariant. Below is the output of the reproducer once the fix is applied: -- compress node 0x560e9c562380 -- free=0, leaves=0 [0] retain node 2/1 [nx 0] [1] fold node 1/1 [nx 0] [2] fold node 0/1 [nx 2] [3] fold node 0/2 [nx 2] [4] fold node 0/3 [nx 2] [5] fold node 0/4 [nx 2] [6] fold node 0/5 [nx 2] [7] fold node 0/6 [nx 2] [8] fold node 0/7 [nx 2] [9] fold node 0/8 [nx 2] [10] fold node 0/9 [nx 2] [11] fold node 0/10 [nx 2] [12] fold node 0/11 [nx 2] [13] fold node 0/12 [nx 2] [14] fold node 0/13 [nx 2] [15] fold node 0/14 [nx 2] internal nodes remain despite enough space, retrying -- compress node 0x560e9c562380 -- free=14, leaves=1 [0] fold node 2/15 [nx 0] after: 3 Changes ======= DH: - Use false instead of 0. - Reorder the inserted lines in a couple of places to put retained before next_slot. ver #2) - Fix typo in pr_devel, correct comparison to "<=" Fixes: 3cb989501c26 ("Add a generic associative array implementation.") Cc: Signed-off-by: Stephen Brennan Signed-off-by: David Howells cc: Andrew Morton cc: keyrings@vger.kernel.org Link: https://lore.kernel.org/r/20220511225517.407935-1-stephen.s.brennan@oracle.com/ # v1 Link: https://lore.kernel.org/r/20220512215045.489140-1-stephen.s.brennan@oracle.com/ # v2 Reviewed-by: Jarkko Sakkinen Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

percpu_ref_init(): clean ->percpu_count_ref on failure

2022-06-06T06:43:36+00:00

[ Upstream commit a91714312eb16f9ecd1f7f8b3efe1380075f28d4 ] That way percpu_ref_exit() is safe after failing percpu_ref_init(). At least one user (cgroup_create()) had a double-free that way; there might be other similar bugs. Easier to fix in percpu_ref_init(), rather than playing whack-a-mole in sloppy users... Usual symptoms look like a messed refcounting in one of subsystems that use percpu allocations (might be percpu-refcount, might be something else). Having refcounts for two different objects share memory is Not Nice(tm)... Reported-by: syzbot+5b1e53987f858500ec00@syzkaller.appspotmail.com Signed-off-by: Al Viro Signed-off-by: Sasha Levin

random: remove ratelimiting for in-kernel unseeded randomness

2022-05-30T07:29:16+00:00

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 Cc: Dominik Brodowski Signed-off-by: Jason A. Donenfeld Signed-off-by: Greg Kroah-Hartman

siphash: use one source of truth for siphash permutations

2022-05-30T07:29:15+00:00

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 Signed-off-by: Greg Kroah-Hartman

random: replace custom notifier chain with standard one

2022-05-30T07:29:10+00:00

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 Cc: Theodore Ts'o Reviewed-by: Dominik Brodowski [Jason: for stable, also backported to crypto/drbg.c, not unexporting.] Signed-off-by: Jason A. Donenfeld Signed-off-by: Greg Kroah-Hartman

random: remove unused tracepoints

2022-05-30T07:29:06+00:00

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 Reviewed-by: Dominik Brodowski Reviewed-by: Eric Biggers Signed-off-by: Jason A. Donenfeld Signed-off-by: Greg Kroah-Hartman

lib/crypto: blake2s: avoid indirect calls to compression function for Clang CFI

2022-05-30T07:28:59+00:00

commit d2a02e3c8bb6b347818518edff5a4b40ff52d6d8 upstream. blake2s_compress_generic is weakly aliased by blake2s_compress. The current harness for function selection uses a function pointer, which is ordinarily inlined and resolved at compile time. But when Clang's CFI is enabled, CFI still triggers when making an indirect call via a weak symbol. This seems like a bug in Clang's CFI, as though it's bucketing weak symbols and strong symbols differently. It also only seems to trigger when "full LTO" mode is used, rather than "thin LTO". [ 0.000000][ T0] Kernel panic - not syncing: CFI failure (target: blake2s_compress_generic+0x0/0x1444) [ 0.000000][ T0] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.16.0-mainline-06981-g076c855b846e #1 [ 0.000000][ T0] Hardware name: MT6873 (DT) [ 0.000000][ T0] Call trace: [ 0.000000][ T0] dump_backtrace+0xfc/0x1dc [ 0.000000][ T0] dump_stack_lvl+0xa8/0x11c [ 0.000000][ T0] panic+0x194/0x464 [ 0.000000][ T0] __cfi_check_fail+0x54/0x58 [ 0.000000][ T0] __cfi_slowpath_diag+0x354/0x4b0 [ 0.000000][ T0] blake2s_update+0x14c/0x178 [ 0.000000][ T0] _extract_entropy+0xf4/0x29c [ 0.000000][ T0] crng_initialize_primary+0x24/0x94 [ 0.000000][ T0] rand_initialize+0x2c/0x6c [ 0.000000][ T0] start_kernel+0x2f8/0x65c [ 0.000000][ T0] __primary_switched+0xc4/0x7be4 [ 0.000000][ T0] Rebooting in 5 seconds.. Nonetheless, the function pointer method isn't so terrific anyway, so this patch replaces it with a simple boolean, which also gets inlined away. This successfully works around the Clang bug. In general, I'm not too keen on all of the indirection involved here; it clearly does more harm than good. Hopefully the whole thing can get cleaned up down the road when lib/crypto is overhauled more comprehensively. But for now, we go with a simple bandaid. Fixes: 6048fdcc5f26 ("lib/crypto: blake2s: include as built-in") Link: https://github.com/ClangBuiltLinux/linux/issues/1567 Reported-by: Miles Chen Tested-by: Miles Chen Tested-by: Nathan Chancellor Tested-by: John Stultz Acked-by: Nick Desaulniers Reviewed-by: Eric Biggers Signed-off-by: Jason A. Donenfeld Signed-off-by: Greg Kroah-Hartman

lib/crypto: sha1: re-roll loops to reduce code size

2022-05-30T07:28:59+00:00

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 Cc: Ard Biesheuvel Tested-by: Geert Uytterhoeven Signed-off-by: Jason A. Donenfeld Signed-off-by: Greg Kroah-Hartman

lib/crypto: blake2s: move hmac construction into wireguard

2022-05-30T07:28:59+00:00

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 Tested-by: Geert Uytterhoeven Acked-by: Ard Biesheuvel Signed-off-by: Jason A. Donenfeld Signed-off-by: Greg Kroah-Hartman