diff --git a/backport-CVE-2021-45944.patch b/backport-CVE-2021-45944.patch new file mode 100644 index 0000000000000000000000000000000000000000..4a9cf6436e67a30a7dcabd0643de31932ddaf800 --- /dev/null +++ b/backport-CVE-2021-45944.patch @@ -0,0 +1,45 @@ +From 7861fcad13c497728189feafb41cd57b5b50ea25 Mon Sep 17 00:00:00 2001 +From: Chris Liddell +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. +--- + psi/zfsample.c | 14 +++++++++++--- + 1 file changed, 11 insertions(+), 3 deletions(-) + +diff --git a/psi/zfsample.c b/psi/zfsample.c +index 290809405d..652ae02c67 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 +Date: Tue, 1 Jun 2021 19:57:16 +0100 +Subject: [PATCH] Bug 703902: Fix op stack management in + sampled_data_continue() + +Replace pop() (which does no checking, and doesn't handle stack extension +blocks) with ref_stack_pop() which does do all that. + +We still use pop() in one case (it's faster), but we have to later use +ref_stack_pop() before calling sampled_data_sample() which also accesses the +op stack. + +Fixes: +https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=34675 +--- + psi/zfsample.c | 16 ++++++++++------ + 1 file changed, 10 insertions(+), 6 deletions(-) + +diff --git a/psi/zfsample.c b/psi/zfsample.c +index 0e8e4bc8dd..00cd0cfdd9 100644 +--- a/psi/zfsample.c ++++ b/psi/zfsample.c +@@ -533,15 +533,19 @@ sampled_data_continue(i_ctx_t *i_ctx_p) + for (j = 0; j < bps; j++) + data_ptr[bps * i + j] = (byte)(cv >> ((bps - 1 - j) * 8)); /* MSB first */ + } +- pop(num_out); /* Move op to base of result values */ + +- /* Check if we are done collecting data. */ ++ pop(num_out); /* Move op to base of result values */ + ++ /* From here on, we have to use ref_stack_pop() rather than pop() ++ so that it handles stack extension blocks properly, before calling ++ sampled_data_sample() which also uses the op stack. ++ */ ++ /* Check if we are done collecting data. */ + if (increment_cube_indexes(params, penum->indexes)) { + if (stack_depth_adjust == 0) +- pop(O_STACK_PAD); /* Remove spare stack space */ ++ ref_stack_pop(&o_stack, O_STACK_PAD); /* Remove spare stack space */ + else +- pop(stack_depth_adjust - num_out); ++ ref_stack_pop(&o_stack, stack_depth_adjust - num_out); + /* Execute the closing procedure, if given */ + code = 0; + if (esp_finish_proc != 0) +@@ -554,11 +558,11 @@ sampled_data_continue(i_ctx_t *i_ctx_p) + 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); ++ ref_stack_pop(&o_stack, stack_depth_adjust); + } + else { + check_ostack(O_STACK_PAD - stack_depth_adjust); +- push(O_STACK_PAD - stack_depth_adjust); ++ ref_stack_push(&o_stack, O_STACK_PAD - stack_depth_adjust); + for (i=0;i - 9.52-5 +- Type:CVE +- ID:CVE-2021-45944 CVE-2021-45949 +- SUG:NA +- DESC:fix CVE-2021-45944 CVE-2021-45949 + * Sat Oct 31 2020 Liquor - 9.52-4 - Type:bugfix - ID:NA