1. 01 May, 2006 10 commits
  2. 24 Apr, 2006 25 commits
  3. 19 Apr, 2006 2 commits
    • Greg Kroah-Hartman's avatar
      Linux 2.6.16.9 · 9d395d19
      Greg Kroah-Hartman authored
      9d395d19
    • Andi Kleen's avatar
      [PATCH] i386/x86-64: Fix x87 information leak between processes (CVE-2006-1056) · 7466f9e7
      Andi Kleen authored
      AMD K7/K8 CPUs only save/restore the FOP/FIP/FDP x87 registers in FXSAVE
      when an exception is pending.  This means the value leak through context
      switches and allow processes to observe some x87 instruction state of
      other processes.
      
      This was actually documented by AMD, but nobody recognized it as being
      different from Intel before.
      
      The fix first adds an optimization: instead of unconditionally calling
      FNCLEX after each FXSAVE test if ES is pending and skip it when not
      needed. Then do a x87 load from a kernel variable to clear FOP/FIP/FDP.
      
      This means other processes always will only see a constant value defined
      by the kernel in their FP state.
      
      I took some pain to make sure to chose a variable that's already in L1
      during context switch to make the overhead of this low.
      
      Also alternative() is used to patch away the new code on CPUs who don't
      need it.
      
      Patch for both i386/x86-64.
      
      The problem was discovered originally by Jan Beulich. Richard Brunner
      provided the basic code for the workarounds, with contribution from Jan.
      
      This is CVE-2006-1056
      
      Cc: richard.brunner@amd.com
      Cc: jbeulich@novell.com
      Signed-off-by: default avatarAndi Kleen <ak@suse.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
      7466f9e7
  4. 18 Apr, 2006 2 commits
  5. 17 Apr, 2006 1 commit