[PATCH] coccinelle: misc: add array_size_dup script to detect missed overlow checks

From: Denis Efremov
Date: Mon Jun 15 2020 - 06:21:19 EST

Next message: Heikki Krogerus: "Re: [PATCH 1/2] dt-bindings: chrome: Add cros-ec-typec mux props"
Previous message: Dominique Martinet: "Re: [PATCH RESEND] 9p: Fix memory leak in v9fs_mount"
Next in thread: Kees Cook: "Re: [PATCH] coccinelle: misc: add array_size_dup script to detect missed overlow checks"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

Detect an opencoded expression that is used before or after
array_size()/array3_size()/struct_size() to compute the same size.

Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: Denis Efremov <efremov@xxxxxxxxx>
---
scripts/coccinelle/misc/array_size_dup.cocci | 347 +++++++++++++++++++
1 file changed, 347 insertions(+)
create mode 100644 scripts/coccinelle/misc/array_size_dup.cocci

diff --git a/scripts/coccinelle/misc/array_size_dup.cocci b/scripts/coccinelle/misc/array_size_dup.cocci
new file mode 100644
index 000000000000..08919a938754
--- /dev/null
+++ b/scripts/coccinelle/misc/array_size_dup.cocci
@@ -0,0 +1,347 @@
+// SPDX-License-Identifier: GPL-2.0-only
+///
+/// Check for array_size(), array3_size(), struct_size() duplicates.
+/// Three types of patterns for these functions:
+/// 1. An opencoded expression is used before array_size() to compute the same size
+/// 2. An opencoded expression is used after array_size() to compute the same size
+/// 3. Consecutive calls of array_size() with the same values
+/// From security point of view only first case is relevant. These functions
+/// perform arithmetic overflow check. Thus, if we use an opencoded expression
+/// before a call to the *_size() function we can miss an overflow.
+///
+// Confidence: High
+// Copyright: (C) 2020 Denis Efremov ISPRAS
+// Options: --no-includes --include-headers --no-loops
+
+virtual context
+virtual report
+virtual org
+
+@as@
+expression E1, E2;
+@@
+
+array_size(E1, E2)
+
+@as_next@
+expression subE1 <= as.E1;
+expression as.E1;
+expression subE2 <= as.E2;
+expression as.E2;
+expression E3;
+position p1, p2;
+@@
+
+* E1 * E2@p1
+ ... when != \(E1\|E2\|subE1\|subE2\)=E3
+ when != \(E1\|E2\|subE1\|subE2\)+=E3
+ when != \(E1\|E2\|subE1\|subE2\)-=E3
+ when != \(E1\|E2\|subE1\|subE2\)*=E3
+ when != \(&E1\|&E2\|&subE1\|&subE2\)
+* array_size(E1, E2)@p2
+
+@as_prev@
+expression subE1 <= as.E1;
+expression as.E1;
+expression subE2 <= as.E2;
+expression as.E2;
+expression E3;
+position p1, p2;
+@@
+
+* array_size(E1, E2)@p1
+ ... when != \(E1\|E2\|subE1\|subE2\)=E3
+ when != \(E1\|E2\|subE1\|subE2\)+=E3
+ when != \(E1\|E2\|subE1\|subE2\)-=E3
+ when != \(E1\|E2\|subE1\|subE2\)*=E3
+ when != \(&E1\|&E2\|&subE1\|&subE2\)
+* E1 * E2@p2
+
+@as_dup@
+expression subE1 <= as.E1;
+expression as.E1;
+expression subE2 <= as.E2;
+expression as.E2;
+expression E3;
+position p1, p2;
+@@
+
+* array_size(E1, E2)@p1
+ ... when != \(E1\|E2\|subE1\|subE2\)=E3
+ when != \(E1\|E2\|subE1\|subE2\)+=E3
+ when != \(E1\|E2\|subE1\|subE2\)-=E3
+ when != \(E1\|E2\|subE1\|subE2\)*=E3
+ when != \(&E1\|&E2\|&subE1\|&subE2\)
+* array_size(E1, E2)@p2
+
+@as3@
+expression E1, E2, E3;
+@@
+
+array3_size(E1, E2, E3)
+
+@as3_next@
+expression subE1 <= as3.E1;
+expression as3.E1;
+expression subE2 <= as3.E2;
+expression as3.E2;
+expression subE3 <= as3.E3;
+expression as3.E3;
+expression E4;
+position p1, p2;
+@@
+
+* E1 * E2 * E3@p1
+ ... when != \(E1\|E2\|E3\|subE1\|subE2\|subE3\)=E4
+ when != \(E1\|E2\|E3\|subE1\|subE2\|subE3\)+=E4
+ when != \(E1\|E2\|E3\|subE1\|subE2\|subE3\)-=E4
+ when != \(E1\|E2\|E3\|subE1\|subE2\|subE3\)*=E4
+ when != \(&E1\|&E2\|&E3\|&subE1\|&subE2\|&subE3\)
+* array3_size(E1, E2, E3)@p2
+
+@as3_prev@
+expression subE1 <= as3.E1;
+expression as3.E1;
+expression subE2 <= as3.E2;
+expression as3.E2;
+expression subE3 <= as3.E3;
+expression as3.E3;
+expression E4;
+position p1, p2;
+@@
+
+* array3_size(E1, E2, E3)@p1
+ ... when != \(E1\|E2\|E3\|subE1\|subE2\|subE3\)=E4
+ when != \(E1\|E2\|E3\|subE1\|subE2\|subE3\)+=E4
+ when != \(E1\|E2\|E3\|subE1\|subE2\|subE3\)-=E4
+ when != \(E1\|E2\|E3\|subE1\|subE2\|subE3\)*=E4
+ when != \(&E1\|&E2\|&E3\|&subE1\|&subE2\|&subE3\)
+* E1 * E2 * E3@p2
+
+@as3_dup@
+expression subE1 <= as3.E1;
+expression as3.E1;
+expression subE2 <= as3.E2;
+expression as3.E2;
+expression subE3 <= as3.E3;
+expression as3.E3;
+expression E4;
+position p1, p2;
+@@
+
+* array3_size(E1, E2, E3)@p1
+ ... when != \(E1\|E2\|E3\|subE1\|subE2\|subE3\)=E4
+ when != \(E1\|E2\|E3\|subE1\|subE2\|subE3\)+=E4
+ when != \(E1\|E2\|E3\|subE1\|subE2\|subE3\)-=E4
+ when != \(E1\|E2\|E3\|subE1\|subE2\|subE3\)*=E4
+ when != \(&E1\|&E2\|&E3\|&subE1\|&subE2\|&subE3\)
+* array3_size(E1, E2, E3)@p2
+
+@ss@
+expression E1, E2, E3;
+@@
+
+struct_size(E1, E2, E3)
+
+@ss_next@
+expression subE1 <= ss.E1;
+expression ss.E1;
+expression subE2 <= ss.E2;
+expression ss.E2;
+expression subE3 <= ss.E3;
+expression ss.E3;
+expression E4;
+position p1, p2;
+@@
+
+* E1 * E2 + E3@p1
+ ... when != \(E1\|E2\|E3\|subE1\|subE2\|subE3\)=E4
+ when != \(E1\|E2\|E3\|subE1\|subE2\|subE3\)+=E4
+ when != \(E1\|E2\|E3\|subE1\|subE2\|subE3\)-=E4
+ when != \(E1\|E2\|E3\|subE1\|subE2\|subE3\)*=E4
+ when != \(&E1\|&E2\|&E3\|&subE1\|&subE2\|&subE3\)
+* struct_size(E1, E2, E3)@p2
+
+@ss_prev@
+expression subE1 <= ss.E1;
+expression ss.E1;
+expression subE2 <= ss.E2;
+expression ss.E2;
+expression subE3 <= ss.E3;
+expression ss.E3;
+expression E4;
+position p1, p2;
+@@
+
+* struct_size(E1, E2, E3)@p1
+ ... when != \(E1\|E2\|E3\|subE1\|subE2\|subE3\)=E4
+ when != \(E1\|E2\|E3\|subE1\|subE2\|subE3\)+=E4
+ when != \(E1\|E2\|E3\|subE1\|subE2\|subE3\)-=E4
+ when != \(E1\|E2\|E3\|subE1\|subE2\|subE3\)*=E4
+ when != \(&E1\|&E2\|&E3\|&subE1\|&subE2\|&subE3\)
+* E1 * E2 + E3@p2
+
+@ss_dup@
+expression subE1 <= ss.E1;
+expression ss.E1;
+expression subE2 <= ss.E2;
+expression ss.E2;
+expression subE3 <= ss.E3;
+expression ss.E3;
+expression E4;
+position p1, p2;
+@@
+
+* struct_size(E1, E2, E3)@p1
+ ... when != \(E1\|E2\|E3\|subE1\|subE2\|subE3\)=E4
+ when != \(E1\|E2\|E3\|subE1\|subE2\|subE3\)+=E4
+ when != \(E1\|E2\|E3\|subE1\|subE2\|subE3\)-=E4
+ when != \(E1\|E2\|E3\|subE1\|subE2\|subE3\)*=E4
+ when != \(&E1\|&E2\|&E3\|&subE1\|&subE2\|&subE3\)
+* struct_size(E1, E2, E3)@p2
+
+@script:python depends on report@
+p1 << as_next.p1;
+p2 << as_next.p2;
+@@
+
+msg = "WARNING: array_size is used down the code (line %s) to compute the same size" % (p2[0].line)
+coccilib.report.print_report(p1[0], msg)
+
+@script:python depends on org@
+p1 << as_next.p1;
+p2 << as_next.p2;
+@@
+
+msg = "WARNING: array_size is used down the code (line %s) to compute the same size" % (p2[0].line)
+coccilib.org.print_todo(p1[0], msg)
+
+@script:python depends on report@
+p1 << as_prev.p1;
+p2 << as_prev.p2;
+@@
+
+msg = "WARNING: array_size is already used (line %s) to compute the same size" % (p1[0].line)
+coccilib.report.print_report(p2[0], msg)
+
+@script:python depends on org@
+p1 << as_prev.p1;
+p2 << as_prev.p2;
+@@
+
+msg = "WARNING: array_size is already used (line %s) to compute the same size" % (p1[0].line)
+coccilib.org.print_todo(p2[0], msg)
+
+@script:python depends on report@
+p1 << as_dup.p1;
+p2 << as_dup.p2;
+@@
+
+msg = "WARNING: same array_size (line %s)" % (p1[0].line)
+coccilib.report.print_report(p2[0], msg)
+
+@script:python depends on org@
+p1 << as_dup.p1;
+p2 << as_dup.p2;
+@@
+
+msg = "WARNING: same array_size (line %s)" % (p1[0].line)
+coccilib.org.print_todo(p2[0], msg)
+
+
+@script:python depends on report@
+p1 << as3_next.p1;
+p2 << as3_next.p2;
+@@
+
+msg = "WARNING: array3_size is used down the code (line %s) to compute the same size" % (p2[0].line)
+coccilib.report.print_report(p1[0], msg)
+
+@script:python depends on org@
+p1 << as3_next.p1;
+p2 << as3_next.p2;
+@@
+
+msg = "WARNING: array3_size is used down the code (line %s) to compute the same size" % (p2[0].line)
+coccilib.org.print_todo(p1[0], msg)
+
+@script:python depends on report@
+p1 << as3_prev.p1;
+p2 << as3_prev.p2;
+@@
+
+msg = "WARNING: array3_size is already used (line %s) to compute the same size" % (p1[0].line)
+coccilib.report.print_report(p2[0], msg)
+
+@script:python depends on org@
+p1 << as3_prev.p1;
+p2 << as3_prev.p2;
+@@
+
+msg = "WARNING: array3_size is already used (line %s) to compute the same size" % (p1[0].line)
+coccilib.org.print_todo(p2[0], msg)
+
+@script:python depends on report@
+p1 << as3_dup.p1;
+p2 << as3_dup.p2;
+@@
+
+msg = "WARNING: same array3_size (line %s)" % (p1[0].line)
+coccilib.report.print_report(p2[0], msg)
+
+@script:python depends on org@
+p1 << as3_dup.p1;
+p2 << as3_dup.p2;
+@@
+
+msg = "WARNING: same array3_size (line %s)" % (p1[0].line)
+coccilib.org.print_todo(p2[0], msg)
+
+
+@script:python depends on report@
+p1 << ss_next.p1;
+p2 << ss_next.p2;
+@@
+
+msg = "WARNING: struct_size is used down the code (line %s) to compute the same size" % (p2[0].line)
+coccilib.report.print_report(p1[0], msg)
+
+@script:python depends on org@
+p1 << ss_next.p1;
+p2 << ss_next.p2;
+@@
+
+msg = "WARNING: struct_size is used down the code (line %s) to compute the same size" % (p2[0].line)
+coccilib.org.print_todo(p1[0], msg)
+
+@script:python depends on report@
+p1 << ss_prev.p1;
+p2 << ss_prev.p2;
+@@
+
+msg = "WARNING: struct_size is already used (line %s) to compute the same size" % (p1[0].line)
+coccilib.report.print_report(p2[0], msg)
+
+@script:python depends on org@
+p1 << ss_prev.p1;
+p2 << ss_prev.p2;
+@@
+
+msg = "WARNING: struct_size is already used (line %s) to compute the same size" % (p1[0].line)
+coccilib.org.print_todo(p2[0], msg)
+
+@script:python depends on report@
+p1 << ss_dup.p1;
+p2 << ss_dup.p2;
+@@
+
+msg = "WARNING: same struct_size (line %s)" % (p1[0].line)
+coccilib.report.print_report(p2[0], msg)
+
+@script:python depends on org@
+p1 << ss_dup.p1;
+p2 << ss_dup.p2;
+@@
+
+msg = "WARNING: same struct_size (line %s)" % (p1[0].line)
+coccilib.org.print_todo(p2[0], msg)
--
2.26.2

Next message: Heikki Krogerus: "Re: [PATCH 1/2] dt-bindings: chrome: Add cros-ec-typec mux props"
Previous message: Dominique Martinet: "Re: [PATCH RESEND] 9p: Fix memory leak in v9fs_mount"
Next in thread: Kees Cook: "Re: [PATCH] coccinelle: misc: add array_size_dup script to detect missed overlow checks"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]