Re: [PATCH] btrfs: allocate btrfs_ioctl_defrag_range_args on stack

[Greg KH]

On Wed, Mar 20, 2024 at 05:14:33PM +0100, David Sterba wrote:
> On Wed, Mar 20, 2024 at 11:31:56AM +0000, Maximilian Heyne wrote:
> > From: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx>
> > 
> > commit c853a5783ebe123847886d432354931874367292 upstream.
> > 
> > Instead of using kmalloc() to allocate btrfs_ioctl_defrag_range_args,
> > allocate btrfs_ioctl_defrag_range_args on stack, the size is reasonably
> > small and ioctls are called in process context.
> > 
> > sizeof(btrfs_ioctl_defrag_range_args) = 48
> > 
> > Reviewed-by: Anand Jain <anand.jain@xxxxxxxxxx>
> > Signed-off-by: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx>
> > Reviewed-by: David Sterba <dsterba@xxxxxxxx>
> > Signed-off-by: David Sterba <dsterba@xxxxxxxx>
> > CC: stable@xxxxxxxxxxxxxxx # 4.14+
> > [ This patch is needed to fix a memory leak of "range" that was
> > introduced when commit 173431b274a9 ("btrfs: defrag: reject unknown
> > flags of btrfs_ioctl_defrag_range_args") was backported to kernels
> > lacking this patch. Now with these two patches applied in reverse order,
> > range->flags needed to change back to range.flags.
> > This bug was discovered and resolved using Coverity Static Analysis
> > Security Testing (SAST) by Synopsys, Inc.]
> > Signed-off-by: Maximilian Heyne <mheyne@xxxxxxxxx>
> 
> Acked-by: David Sterba <dsterba@xxxxxxxx>
> 
> for backport to stable as a prerequisite for 173431b274a9a5 ("btrfs:
> defrag: reject unknown flags of btrfs_ioctl_defrag_range_args").
> 

Now queued up, thanks!

greg k-h