Re: [PATCH v2] crypto: deflate - fix decompression window size

[Herbert Xu <herbert@gondor.apana.org.au>]

On Thu, Mar 26, 2026 at 09:59:22AM +0000, Giovanni Cabiddu wrote:
> deflate_decompress() initializes the inflate stream with windowBits set
> to -DEFLATE_DEF_WINBITS (11 bits, 2KB window). Valid raw DEFLATE streams
> allow window sizes up to MAX_WBITS (15 bits, 32KB).
> 
> Data compressed with a history window larger than 2 KB, for example
> produced by hardware compressors such as QAT or IAA, might not be
> decompressed by deflate-generic since the inflate stream is initialized
> with a 2 KB window. This might be seen, for example, when
> deflate-generic is used as fallback.
> 
> Use -MAX_WBITS when calling zlib_inflateInit2() to accept all valid raw
> DEFLATE streams. The inflate workspace allocated in deflate_alloc_stream()
> is already sized using zlib_inflate_workspacesize(), which accounts for
> the maximum window size, so no allocation change is needed.
> 
> Fixes: f6ded09de8bd ("crypto: acomp - add support for deflate via scomp")
> Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
> Reviewed-by: Laurent M Coquerel <laurent.m.coquerel@intel.com>
> ---
> Changes since v1:
> - Updated commit message to clearly state why this is needed for the
>   deflate algorithm (i.e. allow data produced by HW compressors with
>   larger history windows to be decompressed by deflate-generic, which
>   is used as fallback).
> - Updated fixes tag to point to the commit that introduced deflate
>   support in scomp.
> 
>  crypto/deflate.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

What happened to the parameters patch-set? Wouldn't this be something
that should be treated as a parameter?

Thanks,
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt