2023-01-06 03:44:36

by Gao Xiang

Subject: [PATCH] erofs: fix kvcalloc() misuse with __GFP_NOFAIL

As reported by syzbot [1], kvcalloc() cannot work with __GFP_NOFAIL.
Let's use kcalloc() instead.

[1] https://lore.kernel.org/r/[email protected]
Reported-by: [email protected]
Signed-off-by: Gao Xiang <[email protected]>
---
fs/erofs/zdata.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index ccf7c55d477f..08e982c77985 100644
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -1032,12 +1032,12 @@ static int z_erofs_decompress_pcluster(struct z_erofs_decompress_backend *be,

if (!be->decompressed_pages)
be->decompressed_pages =
- kvcalloc(be->nr_pages, sizeof(struct page *),
- GFP_KERNEL | __GFP_NOFAIL);
+ kcalloc(be->nr_pages, sizeof(struct page *),
+ GFP_KERNEL | __GFP_NOFAIL);
if (!be->compressed_pages)
be->compressed_pages =
- kvcalloc(pclusterpages, sizeof(struct page *),
- GFP_KERNEL | __GFP_NOFAIL);
+ kcalloc(pclusterpages, sizeof(struct page *),
+ GFP_KERNEL | __GFP_NOFAIL);

z_erofs_parse_out_bvecs(be);
err2 = z_erofs_parse_in_bvecs(be, &overlapped);
--
2.24.4

2023-01-06 05:27:22

by Gao Xiang

Subject: Re: [PATCH] erofs: fix kvcalloc() misuse with __GFP_NOFAIL

On 2023/1/6 11:19, Gao Xiang wrote:
> As reported by syzbot [1], kvcalloc() cannot work with __GFP_NOFAIL.
> Let's use kcalloc() instead.
>
> [1] https://lore.kernel.org/r/[email protected]
> Reported-by: [email protected]

Fixes: fe3e5914e6dc ("erofs: try to leave (de)compressed_pages on stack if possible")
Fixes: 4f05687fd703 ("erofs: introduce struct z_erofs_decompress_backend")

> Signed-off-by: Gao Xiang <[email protected]>
> ---
> fs/erofs/zdata.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
> index ccf7c55d477f..08e982c77985 100644
> --- a/fs/erofs/zdata.c
> +++ b/fs/erofs/zdata.c
> @@ -1032,12 +1032,12 @@ static int z_erofs_decompress_pcluster(struct z_erofs_decompress_backend *be,
>
> if (!be->decompressed_pages)
> be->decompressed_pages =
> - kvcalloc(be->nr_pages, sizeof(struct page *),
> - GFP_KERNEL | __GFP_NOFAIL);
> + kcalloc(be->nr_pages, sizeof(struct page *),
> + GFP_KERNEL | __GFP_NOFAIL);
> if (!be->compressed_pages)
> be->compressed_pages =
> - kvcalloc(pclusterpages, sizeof(struct page *),
> - GFP_KERNEL | __GFP_NOFAIL);
> + kcalloc(pclusterpages, sizeof(struct page *),
> + GFP_KERNEL | __GFP_NOFAIL);
>
> z_erofs_parse_out_bvecs(be);
> err2 = z_erofs_parse_in_bvecs(be, &overlapped);

2023-01-09 11:14:39

by Chao Yu

Subject: Re: [PATCH] erofs: fix kvcalloc() misuse with __GFP_NOFAIL

On 2023/1/6 13:06, Gao Xiang wrote:
>
>
> On 2023/1/6 11:19, Gao Xiang wrote:
>> As reported by syzbot [1], kvcalloc() cannot work with  __GFP_NOFAIL.
>> Let's use kcalloc() instead.
>>
>> [1] https://lore.kernel.org/r/[email protected]
>> Reported-by: [email protected]
>
> Fixes: fe3e5914e6dc ("erofs: try to leave (de)compressed_pages on stack if possible")
> Fixes: 4f05687fd703 ("erofs: introduce struct z_erofs_decompress_backend")
>
>> Signed-off-by: Gao Xiang <[email protected]>
>> ---
>>   fs/erofs/zdata.c | 8 ++++----
>>   1 file changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
>> index ccf7c55d477f..08e982c77985 100644
>> --- a/fs/erofs/zdata.c
>> +++ b/fs/erofs/zdata.c
>> @@ -1032,12 +1032,12 @@ static int z_erofs_decompress_pcluster(struct z_erofs_decompress_backend *be,
>>       if (!be->decompressed_pages)
>>           be->decompressed_pages =
>> -            kvcalloc(be->nr_pages, sizeof(struct page *),
>> -                 GFP_KERNEL | __GFP_NOFAIL);
>> +            kcalloc(be->nr_pages, sizeof(struct page *),
>> +                GFP_KERNEL | __GFP_NOFAIL);
>>       if (!be->compressed_pages)
>>           be->compressed_pages =
>> -            kvcalloc(pclusterpages, sizeof(struct page *),
>> -                 GFP_KERNEL | __GFP_NOFAIL);
>> +            kcalloc(pclusterpages, sizeof(struct page *),
>> +                GFP_KERNEL | __GFP_NOFAIL);

How about using kfree instead of kvfree for .decompressed_pages and
.compressed_pages memory release? It's trivial though.

Anyway, feel free to add:

Reviewed-by: Chao Yu <[email protected]>

Thanks,

>>       z_erofs_parse_out_bvecs(be);
>>       err2 = z_erofs_parse_in_bvecs(be, &overlapped);

2023-01-09 13:05:18

by Gao Xiang

Subject: Re: [PATCH] erofs: fix kvcalloc() misuse with __GFP_NOFAIL

Hi Chao,

On 2023/1/9 18:34, Chao Yu wrote:
> On 2023/1/6 13:06, Gao Xiang wrote:
>>
>>
>> On 2023/1/6 11:19, Gao Xiang wrote:
>>> As reported by syzbot [1], kvcalloc() cannot work with  __GFP_NOFAIL.
>>> Let's use kcalloc() instead.
>>>
>>> [1] https://lore.kernel.org/r/[email protected]
>>> Reported-by: [email protected]
>>
>> Fixes: fe3e5914e6dc ("erofs: try to leave (de)compressed_pages on stack if possible")
>> Fixes: 4f05687fd703 ("erofs: introduce struct z_erofs_decompress_backend")
>>
>>> Signed-off-by: Gao Xiang <[email protected]>
>>> ---
>>>   fs/erofs/zdata.c | 8 ++++----
>>>   1 file changed, 4 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
>>> index ccf7c55d477f..08e982c77985 100644
>>> --- a/fs/erofs/zdata.c
>>> +++ b/fs/erofs/zdata.c
>>> @@ -1032,12 +1032,12 @@ static int z_erofs_decompress_pcluster(struct z_erofs_decompress_backend *be,
>>>       if (!be->decompressed_pages)
>>>           be->decompressed_pages =
>>> -            kvcalloc(be->nr_pages, sizeof(struct page *),
>>> -                 GFP_KERNEL | __GFP_NOFAIL);
>>> +            kcalloc(be->nr_pages, sizeof(struct page *),
>>> +                GFP_KERNEL | __GFP_NOFAIL);
>>>       if (!be->compressed_pages)
>>>           be->compressed_pages =
>>> -            kvcalloc(pclusterpages, sizeof(struct page *),
>>> -                 GFP_KERNEL | __GFP_NOFAIL);
>>> +            kcalloc(pclusterpages, sizeof(struct page *),
>>> +                GFP_KERNEL | __GFP_NOFAIL);
>
> How about using kfree instead of kvfree for .decompressed_pages and
> .compressed_pages memory release? It's trivial though.

Yeah, thanks for catching! I will send v2 to fix these.

Thanks,
Gao Xiang

>
> Anyway, feel free to add:
>
> Reviewed-by: Chao Yu <[email protected]>
>
> Thanks,
>
>>>       z_erofs_parse_out_bvecs(be);
>>>       err2 = z_erofs_parse_in_bvecs(be, &overlapped);

2023-01-10 08:36:55

by Gao Xiang

Subject: [PATCH v2] erofs: fix kvcalloc() misuse with __GFP_NOFAIL

As reported by syzbot [1], kvcalloc() cannot work with __GFP_NOFAIL.
Let's use kcalloc() instead.

[1] https://lore.kernel.org/r/[email protected]
Reported-by: [email protected]
Fixes: fe3e5914e6dc ("erofs: try to leave (de)compressed_pages on stack if possible")
Fixes: 4f05687fd703 ("erofs: introduce struct z_erofs_decompress_backend")
Reviewed-by: Chao Yu <[email protected]>
Signed-off-by: Gao Xiang <[email protected]>
---
changes since v1:
- should use kfree() instead of kvfree() as well (Chao);
- add Chao's r-v-b.

fs/erofs/zdata.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index ccf7c55d477f..5200bb86e264 100644
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -1032,12 +1032,12 @@ static int z_erofs_decompress_pcluster(struct z_erofs_decompress_backend *be,

if (!be->decompressed_pages)
be->decompressed_pages =
- kvcalloc(be->nr_pages, sizeof(struct page *),
- GFP_KERNEL | __GFP_NOFAIL);
+ kcalloc(be->nr_pages, sizeof(struct page *),
+ GFP_KERNEL | __GFP_NOFAIL);
if (!be->compressed_pages)
be->compressed_pages =
- kvcalloc(pclusterpages, sizeof(struct page *),
- GFP_KERNEL | __GFP_NOFAIL);
+ kcalloc(pclusterpages, sizeof(struct page *),
+ GFP_KERNEL | __GFP_NOFAIL);

z_erofs_parse_out_bvecs(be);
err2 = z_erofs_parse_in_bvecs(be, &overlapped);
@@ -1085,7 +1085,7 @@ static int z_erofs_decompress_pcluster(struct z_erofs_decompress_backend *be,
}
if (be->compressed_pages < be->onstack_pages ||
be->compressed_pages >= be->onstack_pages + Z_EROFS_ONSTACK_PAGES)
- kvfree(be->compressed_pages);
+ kfree(be->compressed_pages);
z_erofs_fill_other_copies(be, err);

for (i = 0; i < be->nr_pages; ++i) {
@@ -1104,7 +1104,7 @@ static int z_erofs_decompress_pcluster(struct z_erofs_decompress_backend *be,
}

if (be->decompressed_pages != be->onstack_pages)
- kvfree(be->decompressed_pages);
+ kfree(be->decompressed_pages);

pcl->length = 0;
pcl->partial = true;
--
2.24.4