Re: [scarthgap][PATCH] libarchive: fix CVE-2026-14164

[Paul Barker <paul@pbarker.dev>]

On Mon, 2026-07-27 at 09:34 +0200, daniel.turull@ericsson.com wrote:
> From: Daniel Turull <daniel.turull@ericsson.com>
> 
> Backport patch to fix CVE-2026-14164.
> 
> References:
>   https://nvd.nist.gov/vuln/detail/CVE-2026-14164
> 
> Upstream fix:
>   https://github.com/libarchive/libarchive/commit/f774f03b40cb109348e5c6d52b59c864e3cfa8e8
> 
> Signed-off-by: Daniel Turull <daniel.turull@ericsson.com>
> ---
>  .../libarchive/CVE-2026-14164.patch           | 52 +++++++++++++++++++
>  .../libarchive/libarchive_3.7.9.bb            |  1 +
>  2 files changed, 53 insertions(+)
>  create mode 100644 meta/recipes-extended/libarchive/libarchive/CVE-2026-14164.patch
> 
> diff --git a/meta/recipes-extended/libarchive/libarchive/CVE-2026-14164.patch b/meta/recipes-extended/libarchive/libarchive/CVE-2026-14164.patch
> new file mode 100644
> index 00000000000..c94764acf29
> --- /dev/null
> +++ b/meta/recipes-extended/libarchive/libarchive/CVE-2026-14164.patch
> @@ -0,0 +1,52 @@
> +From 5efdd23ea2569314d62492bdc0b078f4dad1f75a Mon Sep 17 00:00:00 2001
> +From: "Dustin L. Howett" <dustin@howett.net>
> +Date: Sun, 24 May 2026 12:43:00 -0500
> +Subject: [PATCH] Merge pull request #3071 from stoeckmann/rar5_doublefree
> +
> +rar5: Avoid dangling pointers in init_unpack
> +(cherry picked from commit 42453cf16255800726b4efedab25138639ceef20)
> +
> +Conflicts Resolved:
> +
> +libarchive/archive_read_support_format_rar5.c (1 conflict):
> +- Stable's init_unpack() is a void function without the calloc failure
> +  checks (`if(...== NULL) return ARCHIVE_FATAL;`) that exist upstream,
> +  since it predates that hardening. Kept the CVE fix logic (unconditionally
> +  setting rar->cstate.window_buf and rar->cstate.filtered_buf to NULL right
> +  after free(), and removing the redundant else-branch that only NULLed
> +  them when window_size <= 0) and omitted the ARCHIVE_FATAL return checks,
> +  which don't apply to this void-returning stable version.
> +
> +Assisted-by: kiro:claude-sonnet-5
> +
> +Changes from upstream commit f774f03b40cb:
> +  - libarchive/archive_read_support_format_rar5.c: adapted from upstream
> +
> +CVE: CVE-2026-14164
> +Upstream-Status: Backport [https://github.com/libarchive/libarchive/commit/f774f03b40cb109348e5c6d52b59c864e3cfa8e8]
> +
> +Signed-off-by: Daniel Turull <daniel.turull@ericsson.com>
> +---
> + libarchive/archive_read_support_format_rar5.c | 6 +++---
> + 1 file changed, 3 insertions(+), 3 deletions(-)
> +
> +diff --git a/libarchive/archive_read_support_format_rar5.c b/libarchive/archive_read_support_format_rar5.c
> +index 736c95a6..098cd6f7 100644
> +--- a/libarchive/archive_read_support_format_rar5.c
> ++++ b/libarchive/archive_read_support_format_rar5.c
> +@@ -2489,12 +2489,12 @@ static void init_unpack(struct rar5* rar) {
> + 	free(rar->cstate.window_buf);
> + 	free(rar->cstate.filtered_buf);
> + 
> ++	rar->cstate.window_buf = NULL;
> ++	rar->cstate.filtered_buf = NULL;
> ++
> + 	if(rar->cstate.window_size > 0) {
> + 		rar->cstate.window_buf = calloc(1, rar->cstate.window_size);
> + 		rar->cstate.filtered_buf = calloc(1, rar->cstate.window_size);
> +-	} else {
> +-		rar->cstate.window_buf = NULL;
> +-		rar->cstate.filtered_buf = NULL;
> + 	}
> + 
> + 	clear_data_ready_stack(rar);

Same comment here as I made on the wrynose patch [1].

[1]: https://lore.kernel.org/openembedded-core/0447ebc9d29b0736de8ba0c75f155ed4f880d072.camel@pbarker.dev/

The `return ARCHIVE_FATAL` paths are not present in libarchive 3.7.9, so
the function can't return between while rar->cstate.filtered_buf is
still a dangling pointer.

Best regards,

-- 
Paul Barker