diff options
| author | Joe Perches <joe@perches.com> | 2017-05-08 15:55:36 -0700 |
|---|---|---|
| committer | Mister Oyster <oysterized@gmail.com> | 2017-09-23 14:00:48 +0200 |
| commit | ac260fe345a63504393226c3665a2176c2737612 (patch) | |
| tree | 4a26117f0956599a9b29c0b3cc14f3230a931c79 | |
| parent | de13061fdf61f32a9ace820fb36bbde76e99ede3 (diff) | |
checkpatch: add ability to find bad uses of vsprintf %p<foo> extensions
%pK was at least once misused at %pk in an out-of-tree module. This
lead to some security concerns. Add the ability to track single and
multiple line statements for misuses of %p<foo>.
[akpm@linux-foundation.org: add helpful comment into lib/vsprintf.c]
[akpm@linux-foundation.org: text tweak]
Link: http://lkml.kernel.org/r/163a690510e636a23187c0dc9caa09ddac6d4cde.1488228427.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: William Roberts <william.c.roberts@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | lib/vsprintf.c | 3 | ||||
| -rwxr-xr-x | scripts/checkpatch.pl | 26 |
2 files changed, 29 insertions, 0 deletions
diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 843cecb63..f3fbfae4f 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -1184,6 +1184,9 @@ int kptr_restrict __read_mostly; * by an extra set of alphanumeric characters that are extended format * specifiers. * + * Please update scripts/checkpatch.pl when adding/removing conversion + * characters. (Search for "check for vsprintf extension"). + * * Right now we handle: * * - 'F' For symbolic function descriptor pointers with offset diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl index baa3c7be0..3ad256036 100755 --- a/scripts/checkpatch.pl +++ b/scripts/checkpatch.pl @@ -5676,6 +5676,32 @@ sub process { } } + # check for vsprintf extension %p<foo> misuses + if ($^V && $^V ge 5.10.0 && + defined $stat && + $stat =~ /^\+(?![^\{]*\{\s*).*\b(\w+)\s*\(.*$String\s*,/s && + $1 !~ /^_*volatile_*$/) { + my $bad_extension = ""; + my $lc = $stat =~ tr@\n@@; + $lc = $lc + $linenr; + for (my $count = $linenr; $count <= $lc; $count++) { + my $fmt = get_quoted_string($lines[$count - 1], raw_line($count, 0)); + $fmt =~ s/%%//g; + if ($fmt =~ /(\%[\*\d\.]*p(?![\WFfSsBKRraEhMmIiUDdgVCbGN]).)/) { + $bad_extension = $1; + last; + } + } + if ($bad_extension ne "") { + my $stat_real = raw_line($linenr, 0); + for (my $count = $linenr + 1; $count <= $lc; $count++) { + $stat_real = $stat_real . "\n" . raw_line($count, 0); + } + WARN("VSPRINTF_POINTER_EXTENSION", + "Invalid vsprintf pointer extension '$bad_extension'\n" . "$here\n$stat_real\n"); + } + } + # Check for misused memsets if ($^V && $^V ge 5.10.0 && defined $stat && |