Protect against sizeof overflows by preferring
kmalloc_array/kcalloc over kmalloc/kzalloc
with a sizeof multiply.
Signed-off-by: Joe Perches <j...@perches.com>
---
V2: Make it a WARN instead.
Add capability to --fix it too.
scripts/checkpatch.pl | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index e7ff52a..7774025 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -4378,6 +4378,30 @@ sub process {
"Prefer $3(sizeof(*$1)...) over $3($4...)\n" .
$herecurr);
}
+# check for k[mz]alloc with multiplies that could be kmalloc_array/kcalloc
+ if ($^V && $^V ge 5.10.0 &&
+ $line =~
/\b($Lval)\s*\=\s*(?:$balanced_parens)?\s*(k[mz]alloc)\s*\(\s*($FuncArg)\s*\*\s*($FuncArg)/)
{
+ my $oldfunc = $3;
+ my $a1 = $4;
+ my $a2 = $10;
+ my $newfunc = "kmalloc_array";
+ $newfunc = "kcalloc" if ($oldfunc eq "kzalloc");
+ if ($a1 =~ /^sizeof\s*\S/ || $a2 =~ /^sizeof\s*\S/) {
+ if (WARN("ALLOC_WITH_MULTIPLY",
+ "Prefer $newfunc over $oldfunc with
multiply\n" . $herecurr) &&
+ $fix) {
+ my $r1 = $a1;
+ my $r2 = $a2;
+ if ($a1 =~ /^sizeof\s*\S/) {
+ $r1 = $a2;
+ $r2 = $a1;
+ }
+ $fixed[$linenr - 1] =~
s/\b($Lval)\s*\=\s*(?:$balanced_parens)?\s*(k[mz]alloc)\s*\(\s*($FuncArg)\s*\*\s*($FuncArg)/$1
. ' = ' . "$newfunc(" . trim($r1) . ', ' . trim($r2)/e;
+
+ }
+ }
+ }
+
# check for krealloc arg reuse
if ($^V && $^V ge 5.10.0 &&
$line =~
/\b($Lval)\s*\=\s*(?:$balanced_parens)?\s*krealloc\s*\(\s*\1\s*,/) {
--
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