xorg-x11-server/patches/xserver-1.4.99-ssh-isnt-local.patch

   1 From 66a3b14e118e90db80f96fcab52af4df35bc2377 Mon Sep 17 00:00:00 2001
   2 From: Adam Jackson <ajax@redhat.com>
   3 Date: Mon, 10 Dec 2007 11:26:57 -0500
   4 Subject: [PATCH] Hack for proper MIT-SHM rejection for ssh-forwarded clients.
   5
   6 ---
   7  Xext/shm.c |   16 ++++++++++++++++
   8  1 file changed, 16 insertions(+)
   9
  10 diff --git a/Xext/shm.c b/Xext/shm.c
  11 index de48020..c011210 100644
  12 --- a/Xext/shm.c
  13 +++ b/Xext/shm.c
  14 @@ -321,8 +321,21 @@ shm_access(ClientPtr client, SHMPERM_TYPE * perm, int readonly)
  15      mode_t mask;
  16      int uidset = 0, gidset = 0;
  17      LocalClientCredRec *lcc;
  18 +    Bool is_ssh = FALSE;
  19
  20      if (GetLocalClientCreds(client, &lcc) != -1) {
  21 +#ifdef linux
  22 +       if (lcc->fieldsSet & LCC_PID_SET) {
  23 +           /* ssh isn't actually a local client */
  24 +           char exe[64], buf[64];
  25 +
  26 +           memset(buf, 0, 64);
  27 +           snprintf(exe, 64, "/proc/%d/exe", lcc->pid);
  28 +           readlink(exe, buf, 63);
  29 +           if (strstr(buf, "/ssh"))
  30 +               is_ssh = TRUE;
  31 +       }
  32 +#endif
  33
  34          if (lcc->fieldsSet & LCC_UID_SET) {
  35              uid = lcc->euid;
  36 @@ -342,6 +355,9 @@ shm_access(ClientPtr client, SHMPERM_TYPE * perm, int readonly)
  37  #endif
  38          FreeLocalClientCreds(lcc);
  39
  40 +        if (is_ssh)
  41 +            return -1;
  42 +
  43          if (uidset) {
  44              /* User id 0 always gets access */
  45              if (uid == 0) {
  46 --
  47 1.7.10.1
  48