1. 07 Aug, 2020 3 commits
    • Willy Tarreau's avatar
      random: fix circular include dependency on arm64 after addition of percpu.h · 6f697da3
      Willy Tarreau authored
      commit 1c9df907 upstream.
      
      Daniel Díaz and Kees Cook independently reported that commit
      f227e3ec ("random32: update the net random state on interrupt and
      activity") broke arm64 due to a circular dependency on include files
      since the addition of percpu.h in random.h.
      
      The correct fix would definitely be to move all the prandom32 stuff out
      of random.h but for backporting, a smaller solution is preferred.
      
      This one replaces linux/percpu.h with asm/percpu.h, and this fixes the
      problem on x86_64, arm64, arm, and mips.  Note that moving percpu.h
      around didn't change anything and that removing it entirely broke
      differently.  When backporting, such options might still be considered
      if this patch fails to help.
      
      [ It turns out that an alternate fix seems to be to just remove the
        troublesome <asm/pointer_auth.h> remove from the arm64 <asm/smp.h>
        that causes the circular dependency.
      
        But we might as well do the whole belt-and-suspenders thing, and
        minimize inclusion in <linux/random.h> too. Either will fix the
        problem, and both are good changes.   - Linus ]
      Reported-by: default avatarDaniel Díaz <daniel.diaz@linaro.org>
      Reported-by: default avatarKees Cook <keescook@chromium.org>
      Tested-by: default avatarMarc Zyngier <maz@kernel.org>
      Fixes: f227e3ec
      Cc: Stephen Rothwell <sfr@canb.auug.org.au>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      6f697da3
    • Grygorii Strashko's avatar
      ARM: percpu.h: fix build error · 546271c2
      Grygorii Strashko authored
      commit aa54ea90 upstream.
      
      Fix build error for the case:
        defined(CONFIG_SMP) && !defined(CONFIG_CPU_V6)
      
      config: keystone_defconfig
      
        CC      arch/arm/kernel/signal.o
        In file included from ../include/linux/random.h:14,
                          from ../arch/arm/kernel/signal.c:8:
        ../arch/arm/include/asm/percpu.h: In function ‘__my_cpu_offset’:
        ../arch/arm/include/asm/percpu.h:29:34: error: ‘current_stack_pointer’ undeclared (first use in this function); did you mean ‘user_stack_pointer’?
            : "Q" (*(const unsigned long *)current_stack_pointer));
                                           ^~~~~~~~~~~~~~~~~~~~~
                                           user_stack_pointer
      
      Fixes: f227e3ec ("random32: update the net random state on interrupt and activity")
      Signed-off-by: default avatarGrygorii Strashko <grygorii.strashko@ti.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      546271c2
    • Willy Tarreau's avatar
      random32: update the net random state on interrupt and activity · 29204c84
      Willy Tarreau authored
      commit f227e3ec 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: default avatarAmit Klein <aksecurity@gmail.com>
      Suggested-by: default avatarLinus 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: default avatarWilly Tarreau <w@1wt.eu>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      29204c84
  2. 05 Aug, 2020 37 commits