toolchain/musl/patches/020-verify-that-ttyname-refers-to-the-same-file-as-the-fd.patch

   1 From 0a950dcf15bb9f7274c804dca490e9e20e475f3e Mon Sep 17 00:00:00 2001
   2 From: Szabolcs Nagy <nsz@port70.net>
   3 Date: Sat, 20 Aug 2016 21:04:31 +0200
   4 Subject: verify that ttyname refers to the same file as the fd
   5
   6 linux containers use separate mount namespace so the /proc
   7 symlink might not point to the right device if the fd was
   8 opened in the parent namespace, in this case return ENOENT.
   9 ---
  10  src/unistd/ttyname_r.c | 15 +++++++++++----
  11  1 file changed, 11 insertions(+), 4 deletions(-)
  12
  13 diff --git a/src/unistd/ttyname_r.c b/src/unistd/ttyname_r.c
  14 index 8bac7b2..a38ba4f 100644
  15 --- a/src/unistd/ttyname_r.c
  16 +++ b/src/unistd/ttyname_r.c
  17 @@ -1,10 +1,12 @@
  18  #include <unistd.h>
  19  #include <errno.h>
  20 +#include <sys/stat.h>
  21
  22  void __procfdname(char *, unsigned);
  23
  24  int ttyname_r(int fd, char *name, size_t size)
  25  {
  26 +       struct stat st1, st2;
  27         char procname[sizeof "/proc/self/fd/" + 3*sizeof(int) + 2];
  28         ssize_t l;
  29
  30 @@ -15,8 +17,13 @@ int ttyname_r(int fd, char *name, size_t size)
  31
  32         if (l < 0) return errno;
  33         else if (l == size) return ERANGE;
  34 -       else {
  35 -               name[l] = 0;
  36 -               return 0;
  37 -       }
  38 +
  39 +       name[l] = 0;
  40 +
  41 +       if (stat(name, &st1) || fstat(fd, &st2))
  42 +               return errno;
  43 +       if (st1.st_dev != st2.st_dev || st1.st_ino != st2.st_ino)
  44 +               return ENOENT;
  45 +
  46 +       return 0;
  47  }
  48 --
  49 cgit v0.11.2