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authorTobin C. Harding <me@tobin.cc>2018-04-10 16:33:31 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-04-11 10:28:36 -0700
commite3c6bc95668b9b9fc1e74f221551dfa622ea9061 (patch)
tree5944aab0e08634b8b89b96f9a95dfa56c0133d40 /scripts/checkpatch.pl
parentcheckpatch: add sub routine get_stat_here() (diff)
downloadlinux-dev-e3c6bc95668b9b9fc1e74f221551dfa622ea9061.tar.xz
linux-dev-e3c6bc95668b9b9fc1e74f221551dfa622ea9061.zip
checkpatch: warn for use of %px
Usage of the new %px specifier potentially leaks sensitive information. Printing kernel addresses exposes the kernel layout in memory, this is potentially exploitable. We have tools in the kernel to help us do the right thing. We can have checkpatch warn developers of potential dangers of using %px. Have checkpatch emit a warning for usage of specifier %px. Link: http://lkml.kernel.org/r/1519700648-23108-5-git-send-email-me@tobin.cc Signed-off-by: Tobin C. Harding <me@tobin.cc> Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to '')
-rwxr-xr-xscripts/checkpatch.pl48
1 files changed, 32 insertions, 16 deletions
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 8be5297d18b6..788c90c1ae2a 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -5812,29 +5812,45 @@ sub process {
defined $stat &&
$stat =~ /^\+(?![^\{]*\{\s*).*\b(\w+)\s*\(.*$String\s*,/s &&
$1 !~ /^_*volatile_*$/) {
- my $bad_extension = "";
+ my $specifier;
+ my $extension;
+ my $bad_specifier = "";
+ my $stat_real;
+
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(?![\WSsBKRraEhMmIiUDdgVCbGNOx]).)/) {
- $bad_extension = $1;
- last;
- }
- }
- if ($bad_extension ne "") {
- my $stat_real = get_stat_real($linenr, $lc);
- my $ext_type = "Invalid";
- my $use = "";
- if ($bad_extension =~ /p[Ff]/) {
- $ext_type = "Deprecated";
- $use = " - use %pS instead";
- $use =~ s/pS/ps/ if ($bad_extension =~ /pf/);
+
+ while ($fmt =~ /(\%[\*\d\.]*p(\w))/g) {
+ $specifier = $1;
+ $extension = $2;
+ if ($extension !~ /[SsBKRraEhMmIiUDdgVCbGNOx]/) {
+ $bad_specifier = $specifier;
+ last;
+ }
+ if ($extension eq "x" && !defined($stat_real)) {
+ if (!defined($stat_real)) {
+ $stat_real = get_stat_real($linenr, $lc);
+ }
+ WARN("VSPRINTF_SPECIFIER_PX",
+ "Using vsprintf specifier '\%px' potentially exposes the kernel memory layout, if you don't really need the address please consider using '\%p'.\n" . "$here\n$stat_real\n");
+ }
}
+ if ($bad_specifier ne "") {
+ my $stat_real = get_stat_real($linenr, $lc);
+ my $ext_type = "Invalid";
+ my $use = "";
+ if ($bad_specifier =~ /p[Ff]/) {
+ $ext_type = "Deprecated";
+ $use = " - use %pS instead";
+ $use =~ s/pS/ps/ if ($bad_specifier =~ /pf/);
+ }
- WARN("VSPRINTF_POINTER_EXTENSION",
- "$ext_type vsprintf pointer extension '$bad_extension'$use\n" . "$here\n$stat_real\n");
+ WARN("VSPRINTF_POINTER_EXTENSION",
+ "$ext_type vsprintf pointer extension '$bad_specifier'$use\n" . "$here\n$stat_real\n");
+ }
}
}