2020-09-11 16:05:11

by Alex Dewar

Subject: [PATCH] scripts: kzfree.cocci: Deprecate use of kzfree

kzfree() is effectively deprecated as of commit 453431a54934 ("mm,
treewide: rename kzfree() to kfree_sensitive()"). It is currently just a
legacy alias for kfree_sensitive(), which achieves the same thing.

Update kzfree.cocci accordingly:
1) Replace instances of kzfree with kfree_sensitive
2) Merge different rules for memset/memset_explicit as kzfree and
kfree_sensitive are now equivalent
3) Rename script to kfree_sensitive.cocci

In addition:
4) Move the script to the free/ subfolder, where it would seem to fit
better

Signed-off-by: Alex Dewar <[email protected]>
---
.../kfree_sensitive.cocci} | 38 +++++--------------
1 file changed, 10 insertions(+), 28 deletions(-)
rename scripts/coccinelle/{api/kzfree.cocci => free/kfree_sensitive.cocci} (59%)

diff --git a/scripts/coccinelle/api/kzfree.cocci b/scripts/coccinelle/free/kfree_sensitive.cocci
similarity index 59%
rename from scripts/coccinelle/api/kzfree.cocci
rename to scripts/coccinelle/free/kfree_sensitive.cocci
index 33625bd7cec9..a87f93f2ed5c 100644
--- a/scripts/coccinelle/api/kzfree.cocci
+++ b/scripts/coccinelle/free/kfree_sensitive.cocci
@@ -1,13 +1,13 @@
// SPDX-License-Identifier: GPL-2.0-only
///
-/// Use kzfree, kvfree_sensitive rather than memset or
-/// memzero_explicit followed by kfree
+/// Use k{,v}free_sensitive rather than memset or memzero_explicit followed by
+/// k{,v}free
///
// Confidence: High
// Copyright: (C) 2020 Denis Efremov ISPRAS
// Options: --no-includes --include-headers
//
-// Keywords: kzfree, kvfree_sensitive
+// Keywords: kfree_sensitive, kvfree_sensitive
//

virtual context
@@ -18,7 +18,7 @@ virtual report
@initialize:python@
@@
# kmalloc_oob_in_memset uses memset to explicitly trigger out-of-bounds access
-filter = frozenset(['kmalloc_oob_in_memset', 'kzfree', 'kvfree_sensitive'])
+filter = frozenset(['kmalloc_oob_in_memset', 'kfree_sensitive', 'kvfree_sensitive'])

def relevant(p):
return not (filter & {el.current_element for el in p})
@@ -53,34 +53,16 @@ position m != cond.ok;
type T;
@@

+(
- memzero_explicit@m((T)E, size);
- ... when != E
- when strict
-// TODO: uncomment when kfree_sensitive will be merged.
-// Only this case is commented out because developers
-// may not like patches like this since kzfree uses memset
-// internally (not memzero_explicit).
-//(
-//- kfree(E)@p;
-//+ kfree_sensitive(E);
-//|
-- \(vfree\|kvfree\)(E)@p;
-+ kvfree_sensitive(E, size);
-//)
-
-@rp_memset depends on patch@
-expression E, size;
-position p : script:python() { relevant(p) };
-position m != cond.ok;
-type T;
-@@
-
+|
- memset@m((T)E, 0, size);
+)
... when != E
when strict
(
- kfree(E)@p;
-+ kzfree(E);
++ kfree_sensitive(E);
|
- \(vfree\|kvfree\)(E)@p;
+ kvfree_sensitive(E, size);
@@ -91,11 +73,11 @@ p << r.p;
@@

coccilib.report.print_report(p[0],
- "WARNING: opportunity for kzfree/kvfree_sensitive")
+ "WARNING: opportunity for k{,v}free_sensitive")

@script:python depends on org@
p << r.p;
@@

coccilib.org.print_todo(p[0],
- "WARNING: opportunity for kzfree/kvfree_sensitive")
+ "WARNING: opportunity for k{,v}free_sensitive")
--
2.28.0

2020-09-11 16:12:58

by Denis Efremov

Subject: Re: [PATCH] scripts: kzfree.cocci: Deprecate use of kzfree

Hi,

same patch
https://lkml.org/lkml/2020/8/11/130

Julia, I've send all the patches to fix existing kfree_sensitive/kvfree_sensitive reports.

https://lkml.org/lkml/2020/8/27/168
https://lkml.org/lkml/2020/8/27/93

Thanks,
Denis

On 9/11/20 4:49 PM, Alex Dewar wrote:
> kzfree() is effectively deprecated as of commit 453431a54934 ("mm,
> treewide: rename kzfree() to kfree_sensitive()"). It is currently just a
> legacy alias for kfree_sensitive(), which achieves the same thing.
>
> Update kzfree.cocci accordingly:
> 1) Replace instances of kzfree with kfree_sensitive
> 2) Merge different rules for memset/memset_explicit as kzfree and
> kfree_sensitive are now equivalent
> 3) Rename script to kfree_sensitive.cocci
>
> In addition:
> 4) Move the script to the free/ subfolder, where it would seem to fit
> better
>
> Signed-off-by: Alex Dewar <[email protected]>
> ---
> .../kfree_sensitive.cocci} | 38 +++++--------------
> 1 file changed, 10 insertions(+), 28 deletions(-)
> rename scripts/coccinelle/{api/kzfree.cocci => free/kfree_sensitive.cocci} (59%)
>
> diff --git a/scripts/coccinelle/api/kzfree.cocci b/scripts/coccinelle/free/kfree_sensitive.cocci
> similarity index 59%
> rename from scripts/coccinelle/api/kzfree.cocci
> rename to scripts/coccinelle/free/kfree_sensitive.cocci
> index 33625bd7cec9..a87f93f2ed5c 100644
> --- a/scripts/coccinelle/api/kzfree.cocci
> +++ b/scripts/coccinelle/free/kfree_sensitive.cocci
> @@ -1,13 +1,13 @@
> // SPDX-License-Identifier: GPL-2.0-only
> ///
> -/// Use kzfree, kvfree_sensitive rather than memset or
> -/// memzero_explicit followed by kfree
> +/// Use k{,v}free_sensitive rather than memset or memzero_explicit followed by
> +/// k{,v}free
> ///
> // Confidence: High
> // Copyright: (C) 2020 Denis Efremov ISPRAS
> // Options: --no-includes --include-headers
> //
> -// Keywords: kzfree, kvfree_sensitive
> +// Keywords: kfree_sensitive, kvfree_sensitive
> //
>
> virtual context
> @@ -18,7 +18,7 @@ virtual report
> @initialize:python@
> @@
> # kmalloc_oob_in_memset uses memset to explicitly trigger out-of-bounds access
> -filter = frozenset(['kmalloc_oob_in_memset', 'kzfree', 'kvfree_sensitive'])
> +filter = frozenset(['kmalloc_oob_in_memset', 'kfree_sensitive', 'kvfree_sensitive'])
>
> def relevant(p):
> return not (filter & {el.current_element for el in p})
> @@ -53,34 +53,16 @@ position m != cond.ok;
> type T;
> @@
>
> +(
> - memzero_explicit@m((T)E, size);
> - ... when != E
> - when strict
> -// TODO: uncomment when kfree_sensitive will be merged.
> -// Only this case is commented out because developers
> -// may not like patches like this since kzfree uses memset
> -// internally (not memzero_explicit).
> -//(
> -//- kfree(E)@p;
> -//+ kfree_sensitive(E);
> -//|
> -- \(vfree\|kvfree\)(E)@p;
> -+ kvfree_sensitive(E, size);
> -//)
> -
> -@rp_memset depends on patch@
> -expression E, size;
> -position p : script:python() { relevant(p) };
> -position m != cond.ok;
> -type T;
> -@@
> -
> +|
> - memset@m((T)E, 0, size);
> +)
> ... when != E
> when strict
> (
> - kfree(E)@p;
> -+ kzfree(E);
> ++ kfree_sensitive(E);
> |
> - \(vfree\|kvfree\)(E)@p;
> + kvfree_sensitive(E, size);
> @@ -91,11 +73,11 @@ p << r.p;
> @@
>
> coccilib.report.print_report(p[0],
> - "WARNING: opportunity for kzfree/kvfree_sensitive")
> + "WARNING: opportunity for k{,v}free_sensitive")
>
> @script:python depends on org@
> p << r.p;
> @@
>
> coccilib.org.print_todo(p[0],
> - "WARNING: opportunity for kzfree/kvfree_sensitive")
> + "WARNING: opportunity for k{,v}free_sensitive")
>

2020-09-11 16:21:25

by Alex Dewar

Subject: Re: [PATCH] scripts: kzfree.cocci: Deprecate use of kzfree

On 2020-09-11 17:08, Denis Efremov wrote:
> Hi,
>
> same patch
> https://lkml.org/lkml/2020/8/11/130
>
> Julia, I've send all the patches to fix existing kfree_sensitive/kvfree_sensitive reports.
>
> https://lkml.org/lkml/2020/8/27/168
> https://lkml.org/lkml/2020/8/27/93
>
> Thanks,
> Denis
Sorry for yet more noise!
>
> On 9/11/20 4:49 PM, Alex Dewar wrote:
>> kzfree() is effectively deprecated as of commit 453431a54934 ("mm,
>> treewide: rename kzfree() to kfree_sensitive()"). It is currently just a
>> legacy alias for kfree_sensitive(), which achieves the same thing.
>>
>> Update kzfree.cocci accordingly:
>> 1) Replace instances of kzfree with kfree_sensitive
>> 2) Merge different rules for memset/memset_explicit as kzfree and
>> kfree_sensitive are now equivalent
>> 3) Rename script to kfree_sensitive.cocci
>>
>> In addition:
>> 4) Move the script to the free/ subfolder, where it would seem to fit
>> better
>>
>> Signed-off-by: Alex Dewar <[email protected]>
>> ---
>> .../kfree_sensitive.cocci} | 38 +++++--------------
>> 1 file changed, 10 insertions(+), 28 deletions(-)
>> rename scripts/coccinelle/{api/kzfree.cocci => free/kfree_sensitive.cocci} (59%)
>>
>> diff --git a/scripts/coccinelle/api/kzfree.cocci b/scripts/coccinelle/free/kfree_sensitive.cocci
>> similarity index 59%
>> rename from scripts/coccinelle/api/kzfree.cocci
>> rename to scripts/coccinelle/free/kfree_sensitive.cocci
>> index 33625bd7cec9..a87f93f2ed5c 100644
>> --- a/scripts/coccinelle/api/kzfree.cocci
>> +++ b/scripts/coccinelle/free/kfree_sensitive.cocci
>> @@ -1,13 +1,13 @@
>> // SPDX-License-Identifier: GPL-2.0-only
>> ///
>> -/// Use kzfree, kvfree_sensitive rather than memset or
>> -/// memzero_explicit followed by kfree
>> +/// Use k{,v}free_sensitive rather than memset or memzero_explicit followed by
>> +/// k{,v}free
>> ///
>> // Confidence: High
>> // Copyright: (C) 2020 Denis Efremov ISPRAS
>> // Options: --no-includes --include-headers
>> //
>> -// Keywords: kzfree, kvfree_sensitive
>> +// Keywords: kfree_sensitive, kvfree_sensitive
>> //
>>
>> virtual context
>> @@ -18,7 +18,7 @@ virtual report
>> @initialize:python@
>> @@
>> # kmalloc_oob_in_memset uses memset to explicitly trigger out-of-bounds access
>> -filter = frozenset(['kmalloc_oob_in_memset', 'kzfree', 'kvfree_sensitive'])
>> +filter = frozenset(['kmalloc_oob_in_memset', 'kfree_sensitive', 'kvfree_sensitive'])
>>
>> def relevant(p):
>> return not (filter & {el.current_element for el in p})
>> @@ -53,34 +53,16 @@ position m != cond.ok;
>> type T;
>> @@
>>
>> +(
>> - memzero_explicit@m((T)E, size);
>> - ... when != E
>> - when strict
>> -// TODO: uncomment when kfree_sensitive will be merged.
>> -// Only this case is commented out because developers
>> -// may not like patches like this since kzfree uses memset
>> -// internally (not memzero_explicit).
>> -//(
>> -//- kfree(E)@p;
>> -//+ kfree_sensitive(E);
>> -//|
>> -- \(vfree\|kvfree\)(E)@p;
>> -+ kvfree_sensitive(E, size);
>> -//)
>> -
>> -@rp_memset depends on patch@
>> -expression E, size;
>> -position p : script:python() { relevant(p) };
>> -position m != cond.ok;
>> -type T;
>> -@@
>> -
>> +|
>> - memset@m((T)E, 0, size);
>> +)
>> ... when != E
>> when strict
>> (
>> - kfree(E)@p;
>> -+ kzfree(E);
>> ++ kfree_sensitive(E);
>> |
>> - \(vfree\|kvfree\)(E)@p;
>> + kvfree_sensitive(E, size);
>> @@ -91,11 +73,11 @@ p << r.p;
>> @@
>>
>> coccilib.report.print_report(p[0],
>> - "WARNING: opportunity for kzfree/kvfree_sensitive")
>> + "WARNING: opportunity for k{,v}free_sensitive")
>>
>> @script:python depends on org@
>> p << r.p;
>> @@
>>
>> coccilib.org.print_todo(p[0],
>> - "WARNING: opportunity for kzfree/kvfree_sensitive")
>> + "WARNING: opportunity for k{,v}free_sensitive")
>>