From de50862520480b90ec2fcaed6ad1ad41462fbf30 Mon Sep 17 00:00:00 2001 From: Denis Efremov Date: Tue, 23 Jun 2020 01:10:56 +0300 Subject: [PATCH] coccinelle: misc: add array_size_dup script to detect missed overflow checks Detect an opencoded expression that is used before or after array_size()/array3_size()/struct_size() to compute the same size. Signed-off-by: Denis Efremov Signed-off-by: Julia Lawall --- scripts/coccinelle/misc/array_size_dup.cocci | 209 +++++++++++++++++++ 1 file changed, 209 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..fbc2ba1401d7 --- /dev/null +++ b/scripts/coccinelle/misc/array_size_dup.cocci @@ -0,0 +1,209 @@ +// SPDX-License-Identifier: GPL-2.0-only +/// +/// Check for array_size(), array3_size(), struct_size() duplicates. +/// These patterns are detected: +/// 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 +/// 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 subE2 <= as.E2; +expression as.E1, as.E2, E3; +assignment operator aop; +position p1, p2; +@@ + +* E1 * E2@p1 + ... when != \(subE1\|subE2\) aop E3 + when != &\(subE1\|subE2\) +* array_size(E1, E2)@p2 + +@script:python depends on report@ +p1 << as_next.p1; +p2 << as_next.p2; +@@ + +msg = "WARNING: array_size is used later (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 later (line %s) to compute the same size" % (p2[0].line) +coccilib.org.print_todo(p1[0], msg) + +@as_prev@ +expression subE1 <= as.E1; +expression subE2 <= as.E2; +expression as.E1, as.E2, E3; +assignment operator aop; +position p1, p2; +@@ + +* array_size(E1, E2)@p1 + ... when != \(subE1\|subE2\) aop E3 + when != &\(subE1\|subE2\) +* E1 * E2@p2 + +@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) + +@as3@ +expression E1, E2, E3; +@@ + +array3_size(E1, E2, E3) + +@as3_next@ +expression subE1 <= as3.E1; +expression subE2 <= as3.E2; +expression subE3 <= as3.E3; +expression as3.E1, as3.E2, as3.E3, E4; +assignment operator aop; +position p1, p2; +@@ + +* E1 * E2 * E3@p1 + ... when != \(subE1\|subE2\|subE3\) aop E4 + when != &\(subE1\|subE2\|subE3\) +* array3_size(E1, E2, E3)@p2 + +@script:python depends on report@ +p1 << as3_next.p1; +p2 << as3_next.p2; +@@ + +msg = "WARNING: array3_size is used later (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 later (line %s) to compute the same size" % (p2[0].line) +coccilib.org.print_todo(p1[0], msg) + +@as3_prev@ +expression subE1 <= as3.E1; +expression subE2 <= as3.E2; +expression subE3 <= as3.E3; +expression as3.E1, as3.E2, as3.E3, E4; +assignment operator aop; +position p1, p2; +@@ + +* array3_size(E1, E2, E3)@p1 + ... when != \(subE1\|subE2\|subE3\) aop E4 + when != &\(subE1\|subE2\|subE3\) +* E1 * E2 * E3@p2 + +@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) + +@ss@ +expression E1, E2, E3; +@@ + +struct_size(E1, E2, E3) + +@ss_next@ +expression subE3 <= ss.E3; +expression ss.E1, ss.E2, ss.E3, E4; +assignment operator aop; +position p1, p2; +@@ + +* E1 * E2 + E3@p1 + ... when != subE3 aop E4 + when != &subE3 +* struct_size(E1, E2, E3)@p2 + +@script:python depends on report@ +p1 << ss_next.p1; +p2 << ss_next.p2; +@@ + +msg = "WARNING: struct_size is used later (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 later (line %s) to compute the same size" % (p2[0].line) +coccilib.org.print_todo(p1[0], msg) + +@ss_prev@ +expression subE3 <= ss.E3; +expression ss.E1, ss.E2, ss.E3, E4; +assignment operator aop; +position p1, p2; +@@ + +* struct_size(E1, E2, E3)@p1 + ... when != subE3 aop E4 + when != &subE3 +* E1 * E2 + E3@p2 + +@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) -- 2.20.1