Messages in this thread Patch in this message | | | From | Kees Cook <> | Subject | [PATCH] checkpatch: Warn about 0-length and 1-element arrays | Date | Wed, 17 May 2023 13:45:37 -0700 |
| |
Fake flexible arrays have been deprecated since last millennium. Proper C99 flexible arrays must be used throughout the kernel so CONFIG_FORTIFY_SOURCE and CONFIG_UBSAN_BOUNDS can provide proper array bounds checking.
Cc: Andy Whitcroft <apw@canonical.com> Cc: Joe Perches <joe@perches.com> Cc: Dwaipayan Ray <dwaipayanray1@gmail.com> Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com> Cc: Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> --- I couldn't find a better way to figure out if a patch line is part of a structure definition. I'm open to ideas! e.g. this would have caught commit f5823fe6897c. --- scripts/checkpatch.pl | 14 ++++++++++++++ 1 file changed, 14 insertions(+)
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl index a90e0ede53ad..415b3c14589b 100755 --- a/scripts/checkpatch.pl +++ b/scripts/checkpatch.pl @@ -7430,6 +7430,20 @@ sub process { } } +# check for fake flexible array declarations (i.e. not in function scope) + if (!defined($context_function)) { + if ($line =~ /^\+\s*((struct|union|enum)\s+$Ident|$Type|})\s+$Ident\s*\[0\][^;]*;/) { + if (WARN("ZERO_LENGTH_ARRAY", + "Use C99 flexible arrays instead of zero-length arrays - see https://github.com/KSPP/linux/issues/78\n" . $herecurr) && $fix) { + $fixed[$fixlinenr] =~ s/\[0\]/[]/g; + } + } + if ($line =~ /^\+\s*((struct|union|enum)\s+$Ident|$Type|})\s+$Ident\s*\[1\][^;]*;/) { + WARN("ONE_ELEMENT_ARRAY", + "Use C99 flexible arrays instead of one-element arrays - see https://github.com/KSPP/linux/issues/79\n" . $herecurr); + } + } + # nested likely/unlikely calls if ($line =~ /\b(?:(?:un)?likely)\s*\(\s*!?\s*(IS_ERR(?:_OR_NULL|_VALUE)?|WARN)/) { WARN("LIKELY_MISUSE", -- 2.34.1
| |