diff options
Diffstat (limited to 'lib/vdso/getrandom.c')
| -rw-r--r-- | lib/vdso/getrandom.c | 31 |
1 files changed, 20 insertions, 11 deletions
diff --git a/lib/vdso/getrandom.c b/lib/vdso/getrandom.c index b230f0b10832..938ca539aaa6 100644 --- a/lib/vdso/getrandom.c +++ b/lib/vdso/getrandom.c @@ -3,15 +3,19 @@ * Copyright (C) 2022-2024 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. */ -#include <linux/cache.h> -#include <linux/kernel.h> -#include <linux/time64.h> +#include <linux/array_size.h> +#include <linux/minmax.h> #include <vdso/datapage.h> #include <vdso/getrandom.h> +#include <vdso/unaligned.h> #include <asm/vdso/getrandom.h> -#include <asm/vdso/vsyscall.h> -#include <asm/unaligned.h> #include <uapi/linux/mman.h> +#include <uapi/linux/random.h> + +#undef PAGE_SIZE +#undef PAGE_MASK +#define PAGE_SIZE (1UL << CONFIG_PAGE_SHIFT) +#define PAGE_MASK (~(PAGE_SIZE - 1)) #define MEMCPY_AND_ZERO_SRC(type, dst, src, len) do { \ while (len >= sizeof(type)) { \ @@ -68,16 +72,17 @@ __cvdso_getrandom_data(const struct vdso_rng_data *rng_info, void *buffer, size_ struct vgetrandom_state *state = opaque_state; size_t batch_len, nblocks, orig_len = len; bool in_use, have_retried = false; - unsigned long current_generation; void *orig_buffer = buffer; + u64 current_generation; u32 counter[2] = { 0 }; if (unlikely(opaque_len == ~0UL && !buffer && !len && !flags)) { - *(struct vgetrandom_opaque_params *)opaque_state = (struct vgetrandom_opaque_params) { - .size_of_opaque_state = sizeof(*state), - .mmap_prot = PROT_READ | PROT_WRITE, - .mmap_flags = MAP_DROPPABLE | MAP_ANONYMOUS - }; + struct vgetrandom_opaque_params *params = opaque_state; + params->size_of_opaque_state = sizeof(*state); + params->mmap_prot = PROT_READ | PROT_WRITE; + params->mmap_flags = MAP_DROPPABLE | MAP_ANONYMOUS; + for (size_t i = 0; i < ARRAY_SIZE(params->reserved); ++i) + params->reserved[i] = 0; return 0; } @@ -85,6 +90,10 @@ __cvdso_getrandom_data(const struct vdso_rng_data *rng_info, void *buffer, size_ if (unlikely(((unsigned long)opaque_state & ~PAGE_MASK) + sizeof(*state) > PAGE_SIZE)) return -EFAULT; + /* Handle unexpected flags by falling back to the kernel. */ + if (unlikely(flags & ~(GRND_NONBLOCK | GRND_RANDOM | GRND_INSECURE))) + goto fallback_syscall; + /* If the caller passes the wrong size, which might happen due to CRIU, fallback. */ if (unlikely(opaque_len != sizeof(*state))) goto fallback_syscall; |