diff options
Diffstat (limited to 'random32-update-the-net-random-state-on-interrupt-and-activity.patch')
| -rw-r--r-- | random32-update-the-net-random-state-on-interrupt-and-activity.patch | 109 |
1 files changed, 0 insertions, 109 deletions
diff --git a/random32-update-the-net-random-state-on-interrupt-and-activity.patch b/random32-update-the-net-random-state-on-interrupt-and-activity.patch deleted file mode 100644 index e929c9976..000000000 --- a/random32-update-the-net-random-state-on-interrupt-and-activity.patch +++ /dev/null @@ -1,109 +0,0 @@ -From f227e3ec3b5cad859ad15666874405e8c1bbc1d4 Mon Sep 17 00:00:00 2001 -From: Willy Tarreau <w@1wt.eu> -Date: Fri, 10 Jul 2020 15:23:19 +0200 -Subject: random32: update the net random state on interrupt and activity - -From: Willy Tarreau <w@1wt.eu> - -commit f227e3ec3b5cad859ad15666874405e8c1bbc1d4 upstream. - -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 <aksecurity@gmail.com> -Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> -Cc: Eric Dumazet <edumazet@google.com> -Cc: "Jason A. Donenfeld" <Jason@zx2c4.com> -Cc: Andy Lutomirski <luto@kernel.org> -Cc: Kees Cook <keescook@chromium.org> -Cc: Thomas Gleixner <tglx@linutronix.de> -Cc: Peter Zijlstra <peterz@infradead.org> -Cc: <stable@vger.kernel.org> -Signed-off-by: Willy Tarreau <w@1wt.eu> -Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> -Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> - ---- - drivers/char/random.c | 1 + - include/linux/random.h | 3 +++ - kernel/time/timer.c | 8 ++++++++ - lib/random32.c | 2 +- - 4 files changed, 13 insertions(+), 1 deletion(-) - ---- a/drivers/char/random.c -+++ b/drivers/char/random.c -@@ -1277,6 +1277,7 @@ void add_interrupt_randomness(int irq, i - - fast_mix(fast_pool); - add_interrupt_bench(cycles); -+ this_cpu_add(net_rand_state.s1, fast_pool->pool[cycles & 3]); - - if (unlikely(crng_init == 0)) { - if ((fast_pool->count >= 64) && ---- a/include/linux/random.h -+++ b/include/linux/random.h -@@ -11,6 +11,7 @@ - #include <linux/kernel.h> - #include <linux/list.h> - #include <linux/once.h> -+#include <linux/percpu.h> - - #include <uapi/linux/random.h> - -@@ -119,6 +120,8 @@ struct rnd_state { - __u32 s1, s2, s3, s4; - }; - -+DECLARE_PER_CPU(struct rnd_state, net_rand_state) __latent_entropy; -+ - u32 prandom_u32_state(struct rnd_state *state); - void prandom_bytes_state(struct rnd_state *state, void *buf, size_t nbytes); - void prandom_seed_full_state(struct rnd_state __percpu *pcpu_state); ---- a/kernel/time/timer.c -+++ b/kernel/time/timer.c -@@ -43,6 +43,7 @@ - #include <linux/sched/debug.h> - #include <linux/slab.h> - #include <linux/compat.h> -+#include <linux/random.h> - - #include <linux/uaccess.h> - #include <asm/unistd.h> -@@ -1743,6 +1744,13 @@ void update_process_times(int user_tick) - scheduler_tick(); - if (IS_ENABLED(CONFIG_POSIX_TIMERS)) - run_posix_cpu_timers(); -+ -+ /* The current CPU might make use of net randoms without receiving IRQs -+ * to renew them often enough. Let's update the net_rand_state from a -+ * non-constant value that's not affine to the number of calls to make -+ * sure it's updated when there's some activity (we don't care in idle). -+ */ -+ this_cpu_add(net_rand_state.s1, rol32(jiffies, 24) + user_tick); - } - - /** ---- a/lib/random32.c -+++ b/lib/random32.c -@@ -48,7 +48,7 @@ static inline void prandom_state_selftes - } - #endif - --static DEFINE_PER_CPU(struct rnd_state, net_rand_state) __latent_entropy; -+DEFINE_PER_CPU(struct rnd_state, net_rand_state) __latent_entropy; - - /** - * prandom_u32_state - seeded pseudo-random number generator. |