Re: [PATCH] zlib: Incorporate fix for CVE-2022-37434

[Michael Tremer <michael.tremer@ipfire.org>]

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Reviewed-by: Michael Tremer <michael.tremer(a)ipfire.org>

> On 7 Aug 2022, at 10:18, Peter Müller <peter.mueller(a)ipfire.org> wrote:
> 
> https://www.cve.org/CVERecord?id=CVE-2022-37434
> 
> Signed-off-by: Peter Müller <peter.mueller(a)ipfire.org>
> ---
> lfs/zlib                              |  4 ++++
> src/patches/zlib-CVE-2022-37434.patch | 29 +++++++++++++++++++++++++++
> 2 files changed, 33 insertions(+)
> create mode 100644 src/patches/zlib-CVE-2022-37434.patch
> 
> diff --git a/lfs/zlib b/lfs/zlib
> index 19740fb7f..8197c9b45 100644
> --- a/lfs/zlib
> +++ b/lfs/zlib
> @@ -77,6 +77,10 @@ $(subst %,%_BLAKE2,$(objects)) :
> $(TARGET) : $(patsubst %,$(DIR_DL)/%,$(objects))
> 	@$(PREBUILD)
> 	@rm -rf $(DIR_APP) && cd $(DIR_SRC) && tar axf $(DIR_DL)/$(DL_FILE)
> +
> +	# Fix for CVE-2022-37434
> +	cd $(DIR_APP) && patch -Np1 < $(DIR_SRC)/src/patches/zlib-CVE-2022-37434.patch
> +
> 	cd $(DIR_APP) && CROSS_PREFIX=$(CROSS_PREFIX) ./configure --prefix=$(PREFIX) --shared
> 	cd $(DIR_APP) && make $(MAKETUNING)
> 	cd $(DIR_APP) && make install
> diff --git a/src/patches/zlib-CVE-2022-37434.patch b/src/patches/zlib-CVE-2022-37434.patch
> new file mode 100644
> index 000000000..95e9f173f
> --- /dev/null
> +++ b/src/patches/zlib-CVE-2022-37434.patch
> @@ -0,0 +1,29 @@
> +commit eff308af425b67093bab25f80f1ae950166bece1
> +Author: Mark Adler <fork(a)madler.net>
> +Date:   Sat Jul 30 15:51:11 2022 -0700
> +
> +    Fix a bug when getting a gzip header extra field with inflate().
> +    
> +    If the extra field was larger than the space the user provided with
> +    inflateGetHeader(), and if multiple calls of inflate() delivered
> +    the extra header data, then there could be a buffer overflow of the
> +    provided space. This commit assures that provided space is not
> +    exceeded.
> +
> +diff --git a/inflate.c b/inflate.c
> +index 7be8c63..7a72897 100644
> +--- a/inflate.c
> ++++ b/inflate.c
> +@@ -763,9 +763,10 @@ int flush;
> +                 copy = state->length;
> +                 if (copy > have) copy = have;
> +                 if (copy) {
> ++                    len = state->head->extra_len - state->length;
> +                     if (state->head != Z_NULL &&
> +-                        state->head->extra != Z_NULL) {
> +-                        len = state->head->extra_len - state->length;
> ++                        state->head->extra != Z_NULL &&
> ++                        len < state->head->extra_max) {
> +                         zmemcpy(state->head->extra + len, next,
> +                                 len + copy > state->head->extra_max ?
> +                                 state->head->extra_max - len : copy);
> -- 
> 2.35.3