diff options
| author | mrg <mrg@NetBSD.org> | 2006-05-12 00:51:13 +0000 |
|---|---|---|
| committer | mrg <mrg@NetBSD.org> | 2006-05-12 00:51:13 +0000 |
| commit | 85a901ce95011611c8b28076ee9fd2fb4e241d74 (patch) | |
| tree | 62fca47a6c70ea759a7b3b7aee2b244184b41985 /gnu/dist/gcc4/libcpp | |
| parent | 871b78e87d8fce19dcd7b7c8bf3e0fca974094d9 (diff) | |
pull across from GCC3 tree:
>date: 2004/11/30 01:51:13; author: jwise; state: Exp; lines: +21 -3
>As discussed on tech-toolchain@netbsd.org, make cpp refuse to attempt to
>parse a #include'd file which does not pass S_ISREG() if the environment variable
>CPP_RESTRICTED is set.
>
>This is primarily intended for use by programs such as calendar(1) which
>use cpp to parse untrusted user files -- without this change (and the corresponding
>change to calendar(1)), any user can cause a denial-of-service for the daily
>calendar -a run by #include'ing a named pipe.
>
>Many thanks to christos@netbsd for his help in polishing this.
Diffstat (limited to 'gnu/dist/gcc4/libcpp')
| -rw-r--r-- | gnu/dist/gcc4/libcpp/files.c | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/gnu/dist/gcc4/libcpp/files.c b/gnu/dist/gcc4/libcpp/files.c index 31c38d0bb80..91091968404 100644 --- a/gnu/dist/gcc4/libcpp/files.c +++ b/gnu/dist/gcc4/libcpp/files.c @@ -28,6 +28,7 @@ Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ #include "mkdeps.h" #include "hashtab.h" #include "md5.h" +#include "../gcc/defaults.h" #include <dirent.h> /* Variable length record files on VMS will have a stat size that includes @@ -191,6 +192,9 @@ static bool check_file_against_entries (cpp_reader *, _cpp_file *, bool); terminal by mistake (this can't happen on sane systems, but paranoia is a virtue). + We do, however, use nonblocking mode if CPP_RESTRICTED, since any + file which can block will be tossed out after fstat(). + Use the three-argument form of open even though we aren't specifying O_CREAT, to defend against broken system headers. @@ -200,20 +204,29 @@ static bool check_file_against_entries (cpp_reader *, _cpp_file *, bool); static bool open_file (_cpp_file *file) { + const char *cpp_restricted; + + GET_ENVIRONMENT(cpp_restricted, "CPP_RESTRICTED"); + if (file->path[0] == '\0') { file->fd = 0; set_stdin_to_binary_mode (); } else - file->fd = open (file->path, O_RDONLY | O_NOCTTY | O_BINARY, 0666); + file->fd = open (file->path, O_RDONLY | O_NOCTTY | O_BINARY + | (cpp_restricted != NULL) ? O_NONBLOCK : 0, 0666); if (file->fd != -1) { if (fstat (file->fd, &file->st) == 0) { - if (!S_ISDIR (file->st.st_mode)) + if (cpp_restricted != NULL + ? S_ISREG (file->st.st_mode) : !S_ISDIR (file->st.st_mode)) { + if (cpp_restricted) + fcntl(file->fd, F_SETFL, + fcntl(file->fd, F_GETFL, 0) & ~O_NONBLOCK); file->err_no = 0; return true; } |
