The patch titled
Subject: checkpatch: warn for use of %px
has been added to the -mm tree. Its filename is
checkpatch-warn-for-use-of-%px.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/checkpatch-warn-for-use-of-%25px.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/checkpatch-warn-for-use-of-%25px.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: "Tobin C. Harding" <me@xxxxxxxx>
Subject: checkpatch: warn for use of %px
Usage of the new %px specifier potentially leaks sensitive inforamtion.
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@xxxxxxxx
Signed-off-by: Tobin C. Harding <me@xxxxxxxx>
Signed-off-by: Joe Perches <joe@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
scripts/checkpatch.pl | 48 ++++++++++++++++++++++++++--------------
1 file changed, 32 insertions(+), 16 deletions(-)
diff -puN scripts/checkpatch.pl~checkpatch-warn-for-use-of-%px scripts/checkpatch.pl
--- a/scripts/checkpatch.pl~checkpatch-warn-for-use-of-%px
+++ a/scripts/checkpatch.pl
@@ -5825,29 +5825,45 @@ 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");
+ }
}
}
_
Patches currently in -mm which might be from me@xxxxxxxx are
checkpatch-add-sub-routine-get_stat_real.patch
checkpatch-remove-unused-variable-declarations.patch
checkpatch-add-sub-routine-get_stat_here.patch
checkpatch-warn-for-use-of-%px.patch
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