user/sven/linux.git/include/linux/random.h, branch v5.6.10

linux/random.h: Mark CONFIG_ARCH_RANDOM functions __must_check

2020-01-25T17:18:50Z

We must not use the pointer output without validating the success of the random read. Reviewed-by: Ard Biesheuvel Signed-off-by: Richard Henderson Signed-off-by: Mark Brown Link: https://lore.kernel.org/r/20200110145422.49141-7-broonie@kernel.org Signed-off-by: Theodore Ts'o

linux/random.h: Use false with bool

2020-01-25T17:18:50Z

Keep the generic fallback versions in sync with the other architecture specific implementations and use the proper name for false. Suggested-by: Ard Biesheuvel Signed-off-by: Richard Henderson Signed-off-by: Mark Brown Link: https://lore.kernel.org/r/20200110145422.49141-6-broonie@kernel.org Signed-off-by: Theodore Ts'o

linux/random.h: Remove arch_has_random, arch_has_random_seed

2020-01-25T17:18:50Z

The arm64 version of archrandom.h will need to be able to test for support and read the random number without preemption, so a separate query predicate is not practical. Since this part of the generic interface is unused, remove it. Signed-off-by: Richard Henderson Signed-off-by: Mark Brown Link: https://lore.kernel.org/r/20200110145422.49141-5-broonie@kernel.org Signed-off-by: Theodore Ts'o

fdt: add support for rng-seed

2019-08-23T15:39:26Z

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 Reviewed-by: Stephen Boyd Reviewed-by: Rob Herring Reviewed-by: Theodore Ts'o # drivers/char/random.c Signed-off-by: Will Deacon

Merge tag 's390-5.2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2019-05-17T17:08:59Z

Pull more s390 updates from Martin Schwidefsky: - Enhancements for the QDIO layer - Remove the RCP trace event - Avoid three build issues - Move the defconfig to the configs directory * tag 's390-5.2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390: move arch/s390/defconfig to arch/s390/configs/defconfig s390/qdio: optimize state inspection of HW-owned SBALs s390/qdio: use get_buf_state() in debug_get_buf_state() s390/qdio: allow to scan all Output SBALs in one go s390/cio: Remove tracing for rchp instruction s390/kasan: adapt disabled_wait usage to avoid build error latent_entropy: avoid build error when plugin cflags are not set s390/boot: fix compiler error due to missing awk strtonum

latent_entropy: avoid build error when plugin cflags are not set

2019-05-08T06:15:52Z

Some architectures set up CFLAGS for linux decompressor phase from scratch and do not include GCC_PLUGINS_CFLAGS. Since "latent_entropy" variable declaration is generated by the plugin code itself including linux/random.h in decompressor code then would cause a build error. E.g. on s390: In file included from ./include/linux/net.h:22, from ./include/linux/skbuff.h:29, from ./include/linux/if_ether.h:23, from ./arch/s390/include/asm/diag.h:12, from arch/s390/boot/startup.c:8: ./include/linux/random.h: In function 'add_latent_entropy': ./include/linux/random.h:26:39: error: 'latent_entropy' undeclared (first use in this function); did you mean 'add_latent_entropy'? 26 | add_device_randomness((const void *)&latent_entropy, | ^~~~~~~~~~~~~~ | add_latent_entropy ./include/linux/random.h:26:39: note: each undeclared identifier is reported only once for each function it appears in The build error is triggered by commit a80313ff91ab ("s390/kernel: introduce .dma sections") which made it into 5.2 merge window. To address that avoid using CONFIG_GCC_PLUGIN_LATENT_ENTROPY in favour of LATENT_ENTROPY_PLUGIN definition which is defined as a part of gcc plugins cflags and hence reflect more accurately when gcc plugin is active. Besides that it is also used for similar purpose in linux/compiler-gcc.h for latent_entropy attribute definition. Signed-off-by: Vasily Gorbik Acked-by: Kees Cook Signed-off-by: Martin Schwidefsky

random: move rand_initialize() earlier

2019-04-20T03:27:05Z

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 Signed-off-by: Theodore Ts'o

random: Make crng state queryable

2018-08-02T21:33:06Z

It is very useful to be able to know whether or not get_random_bytes_wait / wait_for_random_bytes is going to block or not, or whether plain get_random_bytes is going to return good randomness or bad randomness. The particular use case is for mitigating certain attacks in WireGuard. A handshake packet arrives and is queued up. Elsewhere a worker thread takes items from the queue and processes them. In replying to these items, it needs to use some random data, and it has to be good random data. If we simply block until we can have good randomness, then it's possible for an attacker to fill the queue up with packets waiting to be processed. Upon realizing the queue is full, WireGuard will detect that it's under a denial of service attack, and behave accordingly. A better approach is just to drop incoming handshake packets if the crng is not yet initialized. This patch, therefore, makes that information directly accessible. Signed-off-by: Jason A. Donenfeld Signed-off-by: Theodore Ts'o

random: Return nbytes filled from hw RNG

2018-07-18T01:32:48Z

Currently the function get_random_bytes_arch() has return value 'void'. If the hw RNG fails we currently fall back to using get_random_bytes(). This defeats the purpose of requesting random material from the hw RNG in the first place. There are currently no intree users of get_random_bytes_arch(). Only get random bytes from the hw RNG, make function return the number of bytes retrieved from the hw RNG. Acked-by: Theodore Ts'o Reviewed-by: Steven Rostedt (VMware) Signed-off-by: Tobin C. Harding Signed-off-by: Theodore Ts'o

random: always fill buffer in get_random_bytes_wait

2018-02-28T22:59:21Z

In the unfortunate event that a developer fails to check the return value of get_random_bytes_wait, or simply wants to make a "best effort" attempt, for whatever that's worth, it's much better to still fill the buffer with _something_ rather than catastrophically failing in the case of an interruption. This is both a defense in depth measure against inevitable programming bugs, as well as a means of making the API a bit more useful. Signed-off-by: Jason A. Donenfeld Signed-off-by: Theodore Ts'o