gnu: ghostscript: Fix CVE-2023-36664.

* gnu/packages/ghostscript.scm (ghostscript/fixed): New variable.
(ghostscript)[replacement]: Assign it to new field.
* gnu/packages/patches/ghostscript-CVE-2023-36664.patch,
gnu/packages/patches/ghostscript-CVE-2023-36664-fixup.patch: New files.
* gnu/local.mk (dist_patch_DATA): Add them.

1 files changed, 142 insertions, 0 deletions

diff --git a/gnu/packages/patches/ghostscript-CVE-2023-36664.patch b/gnu/packages/patches/ghostscript-CVE-2023-36664.patch
new file mode 100644
index 0000000000..e9c53c1f87
--- /dev/null
+++ b/gnu/packages/patches/ghostscript-CVE-2023-36664.patch
@@ -0,0 +1,142 @@
+From 505eab7782b429017eb434b2b95120855f2b0e3c Mon Sep 17 00:00:00 2001
+From: Chris Liddell <chris.liddell@artifex.com>
+Date: Wed, 7 Jun 2023 10:23:06 +0100
+Subject: [PATCH] Bug 706761: Don't "reduce" %pipe% file names for permission
+ validation
+
+For regular file names, we try to simplfy relative paths before we use them.
+
+Because the %pipe% device can, effectively, accept command line calls, we
+shouldn't be simplifying that string, because the command line syntax can end
+up confusing the path simplifying code. That can result in permitting a pipe
+command which does not match what was originally permitted.
+
+Special case "%pipe" in the validation code so we always deal with the entire
+string.
+---
+ base/gpmisc.c   | 31 +++++++++++++++++++--------
+ base/gslibctx.c | 56 ++++++++++++++++++++++++++++++++++++-------------
+ 2 files changed, 64 insertions(+), 23 deletions(-)
+
+diff --git a/base/gpmisc.c b/base/gpmisc.c
+index 5f39ebba7..2fb87f769 100644
+--- a/base/gpmisc.c
++++ b/base/gpmisc.c
+@@ -1076,16 +1076,29 @@ gp_validate_path_len(const gs_memory_t *mem,
+              && !memcmp(path + cdirstrl, dirsepstr, dirsepstrl)) {
+           prefix_len = 0;
+     }
+-    rlen = len+1;
+-    bufferfull = (char *)gs_alloc_bytes(mem->thread_safe_memory, rlen + prefix_len, "gp_validate_path");
+-    if (bufferfull == NULL)
+-        return gs_error_VMerror;
+-
+-    buffer = bufferfull + prefix_len;
+-    if (gp_file_name_reduce(path, (uint)len, buffer, &rlen) != gp_combine_success)
+-        return gs_error_invalidfileaccess;
+-    buffer[rlen] = 0;
+ 
++    /* "%pipe%" do not follow the normal rules for path definitions, so we
++       don't "reduce" them to avoid unexpected results
++     */
++    if (len > 5 && memcmp(path, "%pipe", 5) != 0) {
++        bufferfull = buffer = (char *)gs_alloc_bytes(mem->thread_safe_memory, len + 1, "gp_validate_path");
++        if (buffer == NULL)
++            return gs_error_VMerror;
++        memcpy(buffer, path, len);
++        buffer[len] = 0;
++        rlen = len;
++    }
++    else {
++        rlen = len+1;
++        bufferfull = (char *)gs_alloc_bytes(mem->thread_safe_memory, rlen + prefix_len, "gp_validate_path");
++        if (bufferfull == NULL)
++            return gs_error_VMerror;
++
++        buffer = bufferfull + prefix_len;
++        if (gp_file_name_reduce(path, (uint)len, buffer, &rlen) != gp_combine_success)
++            return gs_error_invalidfileaccess;
++        buffer[rlen] = 0;
++    }
+     while (1) {
+         switch (mode[0])
+         {
+diff --git a/base/gslibctx.c b/base/gslibctx.c
+index eb566ed06..d2a1aa91d 100644
+--- a/base/gslibctx.c
++++ b/base/gslibctx.c
+@@ -740,14 +740,28 @@ gs_add_control_path_len_flags(const gs_memory_t *mem, gs_path_control_t type, co
+             return gs_error_rangecheck;
+     }
+ 
+-    rlen = len+1;
+-    buffer = (char *)gs_alloc_bytes(core->memory, rlen, "gp_validate_path");
+-    if (buffer == NULL)
+-        return gs_error_VMerror;
++    /* "%pipe%" do not follow the normal rules for path definitions, so we
++       don't "reduce" them to avoid unexpected results
++     */
++    if (len > 5 && memcmp(path, "%pipe", 5) != 0) {
++        buffer = (char *)gs_alloc_bytes(core->memory, len + 1, "gs_add_control_path_len");
++        if (buffer == NULL)
++            return gs_error_VMerror;
++        memcpy(buffer, path, len);
++        buffer[len] = 0;
++        rlen = len;
++    }
++    else {
++        rlen = len + 1;
+ 
+-    if (gp_file_name_reduce(path, (uint)len, buffer, &rlen) != gp_combine_success)
+-        return gs_error_invalidfileaccess;
+-    buffer[rlen] = 0;
++        buffer = (char *)gs_alloc_bytes(core->memory, rlen, "gs_add_control_path_len");
++        if (buffer == NULL)
++            return gs_error_VMerror;
++
++        if (gp_file_name_reduce(path, (uint)len, buffer, &rlen) != gp_combine_success)
++            return gs_error_invalidfileaccess;
++        buffer[rlen] = 0;
++    }
+ 
+     n = control->num;
+     for (i = 0; i < n; i++)
+@@ -833,14 +847,28 @@ gs_remove_control_path_len_flags(const gs_memory_t *mem, gs_path_control_t type,
+             return gs_error_rangecheck;
+     }
+ 
+-    rlen = len+1;
+-    buffer = (char *)gs_alloc_bytes(core->memory, rlen, "gp_validate_path");
+-    if (buffer == NULL)
+-        return gs_error_VMerror;
++    /* "%pipe%" do not follow the normal rules for path definitions, so we
++       don't "reduce" them to avoid unexpected results
++     */
++    if (len > 5 && memcmp(path, "%pipe", 5) != 0) {
++        buffer = (char *)gs_alloc_bytes(core->memory, len + 1, "gs_remove_control_path_len");
++        if (buffer == NULL)
++            return gs_error_VMerror;
++        memcpy(buffer, path, len);
++        buffer[len] = 0;
++        rlen = len;
++    }
++    else {
++        rlen = len+1;
+ 
+-    if (gp_file_name_reduce(path, (uint)len, buffer, &rlen) != gp_combine_success)
+-        return gs_error_invalidfileaccess;
+-    buffer[rlen] = 0;
++        buffer = (char *)gs_alloc_bytes(core->memory, rlen, "gs_remove_control_path_len");
++        if (buffer == NULL)
++            return gs_error_VMerror;
++
++        if (gp_file_name_reduce(path, (uint)len, buffer, &rlen) != gp_combine_success)
++            return gs_error_invalidfileaccess;
++        buffer[rlen] = 0;
++    }
+ 
+     n = control->num;
+     for (i = 0; i < n; i++) {
+-- 
+2.34.1
+