* [PATCH] btrfs: Refactor allocation size calculation in kzalloc()
@ 2025-09-30 9:14 Mehdi Ben Hadj Khelifa
2025-09-30 9:19 ` Qu Wenruo
0 siblings, 1 reply; 3+ messages in thread
From: Mehdi Ben Hadj Khelifa @ 2025-09-30 9:14 UTC (permalink / raw)
To: clm, dsterba
Cc: linux-btrfs, linux-kernel, skhan, david.hunter.linux,
linux-kernel-mentees, Mehdi Ben Hadj Khelifa
Wrap allocation size calculation in size_add() and size_mul() to avoid
any potential overflow.
Signed-off-by: Mehdi Ben Hadj Khelifa <mehdi.benhadjkhelifa@gmail.com>
---
fs/btrfs/volumes.c | 11 +++++------
1 file changed, 5 insertions(+), 6 deletions(-)
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index c6e3efd6f602..3f1f19b28aac 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -6076,12 +6076,11 @@ struct btrfs_io_context *alloc_btrfs_io_context(struct btrfs_fs_info *fs_info,
{
struct btrfs_io_context *bioc;
- bioc = kzalloc(
- /* The size of btrfs_io_context */
- sizeof(struct btrfs_io_context) +
- /* Plus the variable array for the stripes */
- sizeof(struct btrfs_io_stripe) * (total_stripes),
- GFP_NOFS);
+ /* The size of btrfs_io_context */
+ /* Plus the variable array for the stripes */
+ bioc = kzalloc(size_add(sizeof(struct btrfs_io_context),
+ size_mul(sizeof(struct btrfs_io_stripe),
+ total_stripes)), GFP_NOFS);
if (!bioc)
return NULL;
--
2.51.0
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] btrfs: Refactor allocation size calculation in kzalloc()
2025-09-30 9:14 [PATCH] btrfs: Refactor allocation size calculation in kzalloc() Mehdi Ben Hadj Khelifa
@ 2025-09-30 9:19 ` Qu Wenruo
2025-09-30 9:27 ` Mehdi Ben Hadj Khelifa
0 siblings, 1 reply; 3+ messages in thread
From: Qu Wenruo @ 2025-09-30 9:19 UTC (permalink / raw)
To: Mehdi Ben Hadj Khelifa, clm, dsterba
Cc: linux-btrfs, linux-kernel, skhan, david.hunter.linux,
linux-kernel-mentees
在 2025/9/30 18:44, Mehdi Ben Hadj Khelifa 写道:
> Wrap allocation size calculation in size_add() and size_mul() to avoid
> any potential overflow.
>
> Signed-off-by: Mehdi Ben Hadj Khelifa <mehdi.benhadjkhelifa@gmail.com>
> ---
> fs/btrfs/volumes.c | 11 +++++------
> 1 file changed, 5 insertions(+), 6 deletions(-)
>
> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
> index c6e3efd6f602..3f1f19b28aac 100644
> --- a/fs/btrfs/volumes.c
> +++ b/fs/btrfs/volumes.c
> @@ -6076,12 +6076,11 @@ struct btrfs_io_context *alloc_btrfs_io_context(struct btrfs_fs_info *fs_info,
> {
> struct btrfs_io_context *bioc;
>
> - bioc = kzalloc(
> - /* The size of btrfs_io_context */
> - sizeof(struct btrfs_io_context) +
> - /* Plus the variable array for the stripes */
> - sizeof(struct btrfs_io_stripe) * (total_stripes),
> - GFP_NOFS);
> + /* The size of btrfs_io_context */
> + /* Plus the variable array for the stripes */
> + bioc = kzalloc(size_add(sizeof(struct btrfs_io_context),
Please use struct_size() instead.
And if you're using struct_size() there iwll be no need for any comments.
> + size_mul(sizeof(struct btrfs_io_stripe),
> + total_stripes)), GFP_NOFS);
>
> if (!bioc)
> return NULL;
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] btrfs: Refactor allocation size calculation in kzalloc()
2025-09-30 9:19 ` Qu Wenruo
@ 2025-09-30 9:27 ` Mehdi Ben Hadj Khelifa
0 siblings, 0 replies; 3+ messages in thread
From: Mehdi Ben Hadj Khelifa @ 2025-09-30 9:27 UTC (permalink / raw)
To: Qu Wenruo, clm, dsterba
Cc: linux-btrfs, linux-kernel, skhan, david.hunter.linux,
linux-kernel-mentees
On 9/30/25 10:19 AM, Qu Wenruo wrote:
>
>
> 在 2025/9/30 18:44, Mehdi Ben Hadj Khelifa 写道:
>> Wrap allocation size calculation in size_add() and size_mul() to avoid
>> any potential overflow.
>>
>> Signed-off-by: Mehdi Ben Hadj Khelifa <mehdi.benhadjkhelifa@gmail.com>
>> ---
>> fs/btrfs/volumes.c | 11 +++++------
>> 1 file changed, 5 insertions(+), 6 deletions(-)
>>
>> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
>> index c6e3efd6f602..3f1f19b28aac 100644
>> --- a/fs/btrfs/volumes.c
>> +++ b/fs/btrfs/volumes.c
>> @@ -6076,12 +6076,11 @@ struct btrfs_io_context
>> *alloc_btrfs_io_context(struct btrfs_fs_info *fs_info,
>> {
>> struct btrfs_io_context *bioc;
>> - bioc = kzalloc(
>> - /* The size of btrfs_io_context */
>> - sizeof(struct btrfs_io_context) +
>> - /* Plus the variable array for the stripes */
>> - sizeof(struct btrfs_io_stripe) * (total_stripes),
>> - GFP_NOFS);
>> + /* The size of btrfs_io_context */
>> + /* Plus the variable array for the stripes */
>> + bioc = kzalloc(size_add(sizeof(struct btrfs_io_context),
>
> Please use struct_size() instead.
>
> And if you're using struct_size() there iwll be no need for any comments.
Understood, I will get v2 on the way with your recommendation.
Thank you for the suggestion.
Regards,
Mehdi
>> + size_mul(sizeof(struct btrfs_io_stripe),
>> + total_stripes)), GFP_NOFS);
>> if (!bioc)
>> return NULL;
>
^ permalink raw reply [flat|nested] 3+ messages in thread
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2025-09-30 9:14 [PATCH] btrfs: Refactor allocation size calculation in kzalloc() Mehdi Ben Hadj Khelifa
2025-09-30 9:19 ` Qu Wenruo
2025-09-30 9:27 ` Mehdi Ben Hadj Khelifa
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