linux/drivers/char/random.c, branch v5.8

random32: update the net random state on interrupt and activity

2020-07-29T17:35:37Z

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 Suggested-by: Linus Torvalds Cc: Eric Dumazet Cc: "Jason A. Donenfeld" Cc: Andy Lutomirski Cc: Kees Cook Cc: Thomas Gleixner Cc: Peter Zijlstra Cc: Signed-off-by: Willy Tarreau Signed-off-by: Linus Torvalds

Merge branch 'work.sysctl' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2020-06-10T23:05:54Z

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

random: fix an incorrect __user annotation on proc_do_entropy

2020-06-08T14:13:56Z

No user pointers for sysctls anymore. Fixes: 32927393dc1c ("sysctl: pass kernel pointers to ->proc_handler") Reported-by: build test robot Signed-off-by: Christoph Hellwig Signed-off-by: Al Viro

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

2020-06-03T23:27:18Z

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 ...

crypto: lib/sha1 - fold linux/cryptohash.h into crypto/sha.h

2020-05-08T05:32:17Z

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 which already contains constants and functions for SHA-1 (along with SHA-2). Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu

crypto: lib/sha1 - rename "sha" to "sha1"

2020-05-08T05:32:17Z

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 . This prepares for merging into . Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu

sysctl: pass kernel pointers to ->proc_handler

2020-04-27T06:07:40Z

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 Acked-by: Andrey Ignatov Signed-off-by: Al Viro

random: avoid warnings for !CONFIG_NUMA builds

2020-03-19T03:28:17Z

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: 5cbe0f13b51a ("random: split primary/secondary crng init paths") Reported-by: Stephen Rothwell Signed-off-by: Mark Rutland Cc: Theodore Ts'o Signed-off-by: Theodore Ts'o

random: fix data races at timer_rand_state

2020-02-28T04:21:53Z

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 Signed-off-by: Theodore Ts'o

random: always use batched entropy for get_random_u{32,64}

2020-02-28T04:21:52Z

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 Reviewed-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/20200221201037.30231-1-Jason@zx2c4.com Signed-off-by: Theodore Ts'o