Diffstat (limited to 'meta/recipes-extended/ghostscript/ghostscript/CVE-2016-10220.patch')
1 files changed, 55 insertions, 0 deletions
diff --git a/meta/recipes-extended/ghostscript/ghostscript/CVE-2016-10220.patch b/meta/recipes-extended/ghostscript/ghostscript/CVE-2016-10220.patch
new file mode 100644
@@ -0,0 +1,55 @@
+From daf85701dab05f17e924a48a81edc9195b4a04e8 Mon Sep 17 00:00:00 2001
+From: Ken Sharp <firstname.lastname@example.org>
+Date: Wed, 21 Dec 2016 16:54:14 +0000
+Subject: [PATCH] fix crash with bad data supplied to makeimagedevice
+Bug #697450 "Null pointer dereference in gx_device_finalize()"
+The problem here is that the code to finalise a device unconditionally
+frees the icc_struct member of the device structure. However this
+particular (weird) device is not setup as a normal device, probably
+because its very, very ancient. Its possible for the initialisation
+of the device to abort with an error before calling gs_make_mem_device()
+which is where the icc_struct member gets allocated (or set to NULL).
+If that happens, then the cleanup code tries to free the device, which
+calls finalize() which tries to free a garbage pointer.
+Setting the device memory to 0x00 after we allocate it means that the
+icc_struct member will be NULL< and our memory manager allows for that
+happily enough, which avoids the problem.
+Signed-off-by: Catalin Enache <email@example.com>
+ base/gsdevmem.c | 12 ++++++++++++
+ 1 file changed, 12 insertions(+)
+diff --git a/base/gsdevmem.c b/base/gsdevmem.c
+index 97b9cf4..fe75bcc 100644
+@@ -225,6 +225,18 @@ gs_makewordimagedevice(gx_device ** pnew_dev, const gs_matrix * pmat,
+ if (pnew == 0)
++ /* Bug #697450 "Null pointer dereference in gx_device_finalize()"
++ * If we have incorrect data passed to gs_initialise_wordimagedevice() then the
++ * initialisation will fail, crucially it will fail *before* it calls
++ * gs_make_mem_device() which initialises the device. This means that the
++ * icc_struct member will be uninitialsed, but the device finalise method
++ * will unconditionally free that memory. Since its a garbage pointer, bad things happen.
++ * Apparently we do still need makeimagedevice to be available from
++ * PostScript, so in here just zero the device memory, which means that
++ * the finalise routine won't have a problem.
++ memset(pnew, 0x00, st_device_memory.ssize);
+ code = gs_initialize_wordimagedevice(pnew, pmat, width, height,
+ colors, num_colors, word_oriented,
+ page_device, mem);