Messages in this thread | | | Date | Wed, 24 Jun 2020 21:42:34 +0200 (CEST) | From | Julia Lawall <> | Subject | Re: [PATCH v4] coccinelle: misc: add array_size_dup script to detect missed overflow checks |
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On Tue, 23 Jun 2020, Denis Efremov wrote:
> 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 <efremov@linux.com>
Applied, thanks.
julia
> --- > Changes in v2: > - python rules moved next to SmPL patterns > - assignment operator used > - struct_size patterns fixed to check only E3, since > E1, E2 are sizeofs of a structure and a member > of a structure > Changes in v3: > - s/overlow/overflow/ typo fixed (thanks, Markus) > - \(&E1\|&E2\) changed to &\(E1\|E2\) > - print strings breaks removed > Changes in v4: > - duplicates warning removed > - python2 compatability in report&&org modes added > - s/down the code/later/ warning changed > - \(E1\|E2\|subE1\|subE2\) patterns simplified to \(subE1\|subE2\) > > 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..d3d635b2d4fc > --- /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. > +/// 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 > +/// 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) > -- > 2.26.2 > >
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