Ghostscript security fix CVE-2021-3781 (bsc#1190381) OBS-URL: https://build.opensuse.org/request/show/917941 OBS-URL: https://build.opensuse.org/package/show/Printing/ghostscript?expand=0&rev=147
233 lines
8.2 KiB
Diff
233 lines
8.2 KiB
Diff
From a9bd3dec9fde03327a4a2c69dad1036bf9632e20 Mon Sep 17 00:00:00 2001
|
|
From: Chris Liddell <chris.liddell@artifex.com>
|
|
Date: Tue, 7 Sep 2021 20:36:12 +0100
|
|
Subject: [PATCH] Bug 704342: Include device specifier strings in access
|
|
validation
|
|
|
|
for the "%pipe%", %handle%" and %printer% io devices.
|
|
|
|
We previously validated only the part after the "%pipe%" Postscript device
|
|
specifier, but this proved insufficient.
|
|
|
|
This rebuilds the original file name string, and validates it complete. The
|
|
slight complication for "%pipe%" is it can be reached implicitly using
|
|
"|" so we have to check both prefixes.
|
|
|
|
Addresses CVE-2021-3781
|
|
---
|
|
base/gdevpipe.c | 22 +++++++++++++++-
|
|
base/gp_mshdl.c | 11 +++++++-
|
|
base/gp_msprn.c | 10 ++++++-
|
|
base/gp_os2pr.c | 13 +++++++++-
|
|
base/gslibctx.c | 69 ++++++++++---------------------------------------
|
|
5 files changed, 65 insertions(+), 60 deletions(-)
|
|
|
|
diff --git a/base/gdevpipe.c b/base/gdevpipe.c
|
|
index 96d71f5d8..5bdc485be 100644
|
|
--- a/base/gdevpipe.c
|
|
+++ b/base/gdevpipe.c
|
|
@@ -72,8 +72,28 @@ pipe_fopen(gx_io_device * iodev, const char *fname, const char *access,
|
|
#else
|
|
gs_lib_ctx_t *ctx = mem->gs_lib_ctx;
|
|
gs_fs_list_t *fs = ctx->core->fs;
|
|
+ /* The pipe device can be reached in two ways, explicltly with %pipe%
|
|
+ or implicitly with "|", so we have to check for both
|
|
+ */
|
|
+ char f[gp_file_name_sizeof];
|
|
+ const char *pipestr = "|";
|
|
+ const size_t pipestrlen = strlen(pipestr);
|
|
+ const size_t preflen = strlen(iodev->dname);
|
|
+ const size_t nlen = strlen(fname);
|
|
+ int code1;
|
|
+
|
|
+ if (preflen + nlen >= gp_file_name_sizeof)
|
|
+ return_error(gs_error_invalidaccess);
|
|
+
|
|
+ memcpy(f, iodev->dname, preflen);
|
|
+ memcpy(f + preflen, fname, nlen + 1);
|
|
+
|
|
+ code1 = gp_validate_path(mem, f, access);
|
|
+
|
|
+ memcpy(f, pipestr, pipestrlen);
|
|
+ memcpy(f + pipestrlen, fname, nlen + 1);
|
|
|
|
- if (gp_validate_path(mem, fname, access) != 0)
|
|
+ if (code1 != 0 && gp_validate_path(mem, f, access) != 0 )
|
|
return gs_error_invalidfileaccess;
|
|
|
|
/*
|
|
diff --git a/base/gp_mshdl.c b/base/gp_mshdl.c
|
|
index 2b964ed74..8d87ceadc 100644
|
|
--- a/base/gp_mshdl.c
|
|
+++ b/base/gp_mshdl.c
|
|
@@ -95,8 +95,17 @@ mswin_handle_fopen(gx_io_device * iodev, const char *fname, const char *access,
|
|
long hfile; /* Correct for Win32, may be wrong for Win64 */
|
|
gs_lib_ctx_t *ctx = mem->gs_lib_ctx;
|
|
gs_fs_list_t *fs = ctx->core->fs;
|
|
+ char f[gp_file_name_sizeof];
|
|
+ const size_t preflen = strlen(iodev->dname);
|
|
+ const size_t nlen = strlen(fname);
|
|
|
|
- if (gp_validate_path(mem, fname, access) != 0)
|
|
+ if (preflen + nlen >= gp_file_name_sizeof)
|
|
+ return_error(gs_error_invalidaccess);
|
|
+
|
|
+ memcpy(f, iodev->dname, preflen);
|
|
+ memcpy(f + preflen, fname, nlen + 1);
|
|
+
|
|
+ if (gp_validate_path(mem, f, access) != 0)
|
|
return gs_error_invalidfileaccess;
|
|
|
|
/* First we try the open_handle method. */
|
|
diff --git a/base/gp_msprn.c b/base/gp_msprn.c
|
|
index ed4827968..746a974f7 100644
|
|
--- a/base/gp_msprn.c
|
|
+++ b/base/gp_msprn.c
|
|
@@ -168,8 +168,16 @@ mswin_printer_fopen(gx_io_device * iodev, const char *fname, const char *access,
|
|
uintptr_t *ptid = &((tid_t *)(iodev->state))->tid;
|
|
gs_lib_ctx_t *ctx = mem->gs_lib_ctx;
|
|
gs_fs_list_t *fs = ctx->core->fs;
|
|
+ const size_t preflen = strlen(iodev->dname);
|
|
+ const size_t nlen = strlen(fname);
|
|
|
|
- if (gp_validate_path(mem, fname, access) != 0)
|
|
+ if (preflen + nlen >= gp_file_name_sizeof)
|
|
+ return_error(gs_error_invalidaccess);
|
|
+
|
|
+ memcpy(pname, iodev->dname, preflen);
|
|
+ memcpy(pname + preflen, fname, nlen + 1);
|
|
+
|
|
+ if (gp_validate_path(mem, pname, access) != 0)
|
|
return gs_error_invalidfileaccess;
|
|
|
|
/* First we try the open_printer method. */
|
|
diff --git a/base/gp_os2pr.c b/base/gp_os2pr.c
|
|
index f852c71fc..ba54cde66 100644
|
|
--- a/base/gp_os2pr.c
|
|
+++ b/base/gp_os2pr.c
|
|
@@ -107,9 +107,20 @@ os2_printer_fopen(gx_io_device * iodev, const char *fname, const char *access,
|
|
FILE ** pfile, char *rfname, uint rnamelen)
|
|
{
|
|
os2_printer_t *pr = (os2_printer_t *)iodev->state;
|
|
- char driver_name[256];
|
|
+ char driver_name[gp_file_name_sizeof];
|
|
gs_lib_ctx_t *ctx = mem->gs_lib_ctx;
|
|
gs_fs_list_t *fs = ctx->core->fs;
|
|
+ const size_t preflen = strlen(iodev->dname);
|
|
+ const int size_t = strlen(fname);
|
|
+
|
|
+ if (preflen + nlen >= gp_file_name_sizeof)
|
|
+ return_error(gs_error_invalidaccess);
|
|
+
|
|
+ memcpy(driver_name, iodev->dname, preflen);
|
|
+ memcpy(driver_name + preflen, fname, nlen + 1);
|
|
+
|
|
+ if (gp_validate_path(mem, driver_name, access) != 0)
|
|
+ return gs_error_invalidfileaccess;
|
|
|
|
/* First we try the open_printer method. */
|
|
/* Note that the loop condition here ensures we don't
|
|
diff --git a/base/gslibctx.c b/base/gslibctx.c
|
|
index 6dfed6cd5..318039fad 100644
|
|
--- a/base/gslibctx.c
|
|
+++ b/base/gslibctx.c
|
|
@@ -655,82 +655,39 @@ rewrite_percent_specifiers(char *s)
|
|
int
|
|
gs_add_outputfile_control_path(gs_memory_t *mem, const char *fname)
|
|
{
|
|
- char *fp, f[gp_file_name_sizeof];
|
|
- const int pipe = 124; /* ASCII code for '|' */
|
|
- const int len = strlen(fname);
|
|
- int i, code;
|
|
+ char f[gp_file_name_sizeof];
|
|
+ int code;
|
|
|
|
/* Be sure the string copy will fit */
|
|
- if (len >= gp_file_name_sizeof)
|
|
+ if (strlen(fname) >= gp_file_name_sizeof)
|
|
return gs_error_rangecheck;
|
|
strcpy(f, fname);
|
|
- fp = f;
|
|
/* Try to rewrite any %d (or similar) in the string */
|
|
rewrite_percent_specifiers(f);
|
|
- for (i = 0; i < len; i++) {
|
|
- if (f[i] == pipe) {
|
|
- fp = &f[i + 1];
|
|
- /* Because we potentially have to check file permissions at two levels
|
|
- for the output file (gx_device_open_output_file and the low level
|
|
- fopen API, if we're using a pipe, we have to add both the full string,
|
|
- (including the '|', and just the command to which we pipe - since at
|
|
- the pipe_fopen(), the leading '|' has been stripped.
|
|
- */
|
|
- code = gs_add_control_path(mem, gs_permit_file_writing, f);
|
|
- if (code < 0)
|
|
- return code;
|
|
- code = gs_add_control_path(mem, gs_permit_file_control, f);
|
|
- if (code < 0)
|
|
- return code;
|
|
- break;
|
|
- }
|
|
- if (!IS_WHITESPACE(f[i]))
|
|
- break;
|
|
- }
|
|
- code = gs_add_control_path(mem, gs_permit_file_control, fp);
|
|
+
|
|
+ code = gs_add_control_path(mem, gs_permit_file_control, f);
|
|
if (code < 0)
|
|
return code;
|
|
- return gs_add_control_path(mem, gs_permit_file_writing, fp);
|
|
+ return gs_add_control_path(mem, gs_permit_file_writing, f);
|
|
}
|
|
|
|
int
|
|
gs_remove_outputfile_control_path(gs_memory_t *mem, const char *fname)
|
|
{
|
|
- char *fp, f[gp_file_name_sizeof];
|
|
- const int pipe = 124; /* ASCII code for '|' */
|
|
- const int len = strlen(fname);
|
|
- int i, code;
|
|
+ char f[gp_file_name_sizeof];
|
|
+ int code;
|
|
|
|
/* Be sure the string copy will fit */
|
|
- if (len >= gp_file_name_sizeof)
|
|
+ if (strlen(fname) >= gp_file_name_sizeof)
|
|
return gs_error_rangecheck;
|
|
strcpy(f, fname);
|
|
- fp = f;
|
|
/* Try to rewrite any %d (or similar) in the string */
|
|
- for (i = 0; i < len; i++) {
|
|
- if (f[i] == pipe) {
|
|
- fp = &f[i + 1];
|
|
- /* Because we potentially have to check file permissions at two levels
|
|
- for the output file (gx_device_open_output_file and the low level
|
|
- fopen API, if we're using a pipe, we have to add both the full string,
|
|
- (including the '|', and just the command to which we pipe - since at
|
|
- the pipe_fopen(), the leading '|' has been stripped.
|
|
- */
|
|
- code = gs_remove_control_path(mem, gs_permit_file_writing, f);
|
|
- if (code < 0)
|
|
- return code;
|
|
- code = gs_remove_control_path(mem, gs_permit_file_control, f);
|
|
- if (code < 0)
|
|
- return code;
|
|
- break;
|
|
- }
|
|
- if (!IS_WHITESPACE(f[i]))
|
|
- break;
|
|
- }
|
|
- code = gs_remove_control_path(mem, gs_permit_file_control, fp);
|
|
+ rewrite_percent_specifiers(f);
|
|
+
|
|
+ code = gs_remove_control_path(mem, gs_permit_file_control, f);
|
|
if (code < 0)
|
|
return code;
|
|
- return gs_remove_control_path(mem, gs_permit_file_writing, fp);
|
|
+ return gs_remove_control_path(mem, gs_permit_file_writing, f);
|
|
}
|
|
|
|
int
|
|
--
|
|
2.17.1
|
|
|