diff options
Diffstat (limited to 'meta/recipes-extended/ghostscript/ghostscript/check-stack-limits-after-function-evalution.patch')
-rw-r--r-- | meta/recipes-extended/ghostscript/ghostscript/check-stack-limits-after-function-evalution.patch | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/meta/recipes-extended/ghostscript/ghostscript/check-stack-limits-after-function-evalution.patch b/meta/recipes-extended/ghostscript/ghostscript/check-stack-limits-after-function-evalution.patch new file mode 100644 index 0000000000..722bab4ddb --- /dev/null +++ b/meta/recipes-extended/ghostscript/ghostscript/check-stack-limits-after-function-evalution.patch @@ -0,0 +1,51 @@ +From 7861fcad13c497728189feafb41cd57b5b50ea25 Mon Sep 17 00:00:00 2001 +From: Chris Liddell <chris.liddell@artifex.com> +Date: Fri, 12 Feb 2021 10:34:23 +0000 +Subject: [PATCH] oss-fuzz 30715: Check stack limits after function evaluation. + +During function result sampling, after the callout to the Postscript +interpreter, make sure there is enough stack space available before pushing +or popping entries. + +In thise case, the Postscript procedure for the "function" is totally invalid +(as a function), and leaves the op stack in an unrecoverable state (as far as +function evaluation is concerned). We end up popping more entries off the +stack than are available. + +To cope, add in stack limit checking to throw an appropriate error when this +happens. + +Upstream-Status: Backported [https://git.ghostscript.com/?p=ghostpdl.git;a=patch;h=7861fcad13c497728189feafb41cd57b5b50ea25] +Signed-off-by: Minjae Kim <flowergom@gmail.com> +--- + psi/zfsample.c | 14 +++++++++++--- + 1 file changed, 11 insertions(+), 3 deletions(-) + +diff --git a/psi/zfsample.c b/psi/zfsample.c +index 290809405..652ae02c6 100644 +--- a/psi/zfsample.c ++++ b/psi/zfsample.c +@@ -551,9 +551,17 @@ sampled_data_continue(i_ctx_t *i_ctx_p) + } else { + if (stack_depth_adjust) { + stack_depth_adjust -= num_out; +- push(O_STACK_PAD - stack_depth_adjust); +- for (i=0;i<O_STACK_PAD - stack_depth_adjust;i++) +- make_null(op - i); ++ if ((O_STACK_PAD - stack_depth_adjust) < 0) { ++ stack_depth_adjust = -(O_STACK_PAD - stack_depth_adjust); ++ check_op(stack_depth_adjust); ++ pop(stack_depth_adjust); ++ } ++ else { ++ check_ostack(O_STACK_PAD - stack_depth_adjust); ++ push(O_STACK_PAD - stack_depth_adjust); ++ for (i=0;i<O_STACK_PAD - stack_depth_adjust;i++) ++ make_null(op - i); ++ } + } + } + +-- +2.25.1 + |