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| author | Jacob Keller <jacob.e.keller@intel.com> | 2023-02-27 12:24:28 -0800 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2024-02-29 13:38:01 -0800 |
| commit | e7549481255167dcdab355c539562c7ace17e111 (patch) | |
| tree | abc01d0800b8e65bc2bccad2be0aeda1981535ca /scripts/coccinelle | |
| parent | 1d02f252339e2eaf3ba35b9dc77e7a1a9aa7414c (diff) | |
| download | linux-e7549481255167dcdab355c539562c7ace17e111.tar.gz linux-e7549481255167dcdab355c539562c7ace17e111.tar.bz2 linux-e7549481255167dcdab355c539562c7ace17e111.zip | |
coccinelle: semantic patch to check for potential struct_size calls
include/linux/overflow.h includes helper macros intended for calculating
sizes of allocations. These macros prevent accidental overflow by
saturating at SIZE_MAX.
In general when calculating such sizes use of the macros is preferred. Add
a semantic patch which can detect code patterns which can be replaced by
struct_size.
Note that I set the confidence to medium because this patch doesn't make an
attempt to ensure that the relevant array is actually a flexible array. The
struct_size macro does specifically require a flexible array. In many cases
the detected code could be refactored to a flexible array, but this is not
always possible (such as if there are multiple over-allocations).
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://lore.kernel.org/r/20230227202428.3657443-1-jacob.e.keller@intel.com
Signed-off-by: Kees Cook <keescook@chromium.org>
Diffstat (limited to 'scripts/coccinelle')
| -rw-r--r-- | scripts/coccinelle/misc/struct_size.cocci | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/scripts/coccinelle/misc/struct_size.cocci b/scripts/coccinelle/misc/struct_size.cocci new file mode 100644 index 000000000000..9b02c37438e4 --- /dev/null +++ b/scripts/coccinelle/misc/struct_size.cocci @@ -0,0 +1,74 @@ +// SPDX-License-Identifier: GPL-2.0-only +/// +/// Check for code that could use struct_size(). +/// +// Confidence: Medium +// Author: Jacob Keller <jacob.e.keller@intel.com> +// Copyright: (C) 2023 Intel Corporation +// Options: --no-includes --include-headers + +virtual patch +virtual context +virtual org +virtual report + +// the overflow Kunit tests have some code which intentionally does not use +// the macros, so we want to ignore this code when reporting potential +// issues. +@overflow_tests@ +identifier f = overflow_size_helpers_test; +@@ + +f + +//---------------------------------------------------------- +// For context mode +//---------------------------------------------------------- + +@depends on !overflow_tests && context@ +expression E1, E2; +identifier m; +@@ +( +* (sizeof(*E1) + (E2 * sizeof(*E1->m))) +) + +//---------------------------------------------------------- +// For patch mode +//---------------------------------------------------------- + +@depends on !overflow_tests && patch@ +expression E1, E2; +identifier m; +@@ +( +- (sizeof(*E1) + (E2 * sizeof(*E1->m))) ++ struct_size(E1, m, E2) +) + +//---------------------------------------------------------- +// For org and report mode +//---------------------------------------------------------- + +@r depends on !overflow_tests && (org || report)@ +expression E1, E2; +identifier m; +position p; +@@ +( + (sizeof(*E1)@p + (E2 * sizeof(*E1->m))) +) + +@script:python depends on org@ +p << r.p; +@@ + +coccilib.org.print_todo(p[0], "WARNING should use struct_size") + +@script:python depends on report@ +p << r.p; +@@ + +msg="WARNING: Use struct_size" +coccilib.report.print_report(p[0], msg) + |