Add patch for double free

Resolves: RHEL-93904
This commit is contained in:
Wim Taymans 2025-06-03 17:11:22 +02:00
parent 814596c8fe
commit a038e5f79b
2 changed files with 71 additions and 1 deletions

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@ -0,0 +1,63 @@
From 0bbd41115d5afefe3cf789f7ed2e73c52d3f1a0b Mon Sep 17 00:00:00 2001
From: James Zern <jzern@google.com>
Date: Wed, 30 Apr 2025 19:28:48 -0700
Subject: [PATCH] vpx_codec_enc_init_multi: fix double free on init failure
In `vp8e_init()`, the encoder would take ownership of
`mr_cfg.mr_low_res_mode_info` even if `vp8_create_compressor()` failed.
This caused confusion at the call site as other failures in
`vp8e_init()` did not result in ownership transfer and the caller would
free the memory. In the case of `vp8_create_compressor()` failure both
the caller and `vpx_codec_destroy()` would free the memory, causing a
crash. `mr_*` related variables are now cleared on failure to prevent
this situation.
Bug: webm:413411335
Bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1962421
Change-Id: Ie951d42b9029a586bf9059b650bd8863db9f9ffc
(cherry picked from commit 1c758781c428c0e895645b95b8ff1512b6bdcecb)
---
vp8/vp8_cx_iface.c | 12 +++++++++++-
vpx/src/vpx_encoder.c | 3 +++
2 files changed, 14 insertions(+), 1 deletion(-)
diff --git a/vp8/vp8_cx_iface.c b/vp8/vp8_cx_iface.c
index a6f0b4cbc..19e836690 100644
--- a/vp8/vp8_cx_iface.c
+++ b/vp8/vp8_cx_iface.c
@@ -722,7 +722,17 @@ static vpx_codec_err_t vp8e_init(vpx_codec_ctx_t *ctx,
set_vp8e_config(&priv->oxcf, priv->cfg, priv->vp8_cfg, mr_cfg);
priv->cpi = vp8_create_compressor(&priv->oxcf);
- if (!priv->cpi) res = VPX_CODEC_MEM_ERROR;
+ if (!priv->cpi) {
+#if CONFIG_MULTI_RES_ENCODING
+ // Release ownership of mr_cfg->mr_low_res_mode_info on failure. This
+ // prevents ownership confusion with the caller and avoids a double
+ // free when vpx_codec_destroy() is called on this instance.
+ priv->oxcf.mr_total_resolutions = 0;
+ priv->oxcf.mr_encoder_id = 0;
+ priv->oxcf.mr_low_res_mode_info = NULL;
+#endif
+ res = VPX_CODEC_MEM_ERROR;
+ }
}
}
diff --git a/vpx/src/vpx_encoder.c b/vpx/src/vpx_encoder.c
index 0d6e48015..5667d1297 100644
--- a/vpx/src/vpx_encoder.c
+++ b/vpx/src/vpx_encoder.c
@@ -113,6 +113,9 @@ vpx_codec_err_t vpx_codec_enc_init_multi_ver(
ctx->priv = NULL;
ctx->init_flags = flags;
ctx->config.enc = cfg;
+ // ctx takes ownership of mr_cfg.mr_low_res_mode_info if and only if
+ // this call succeeds. The first ctx entry in the array is
+ // responsible for freeing the memory.
res = ctx->iface->init(ctx, &mr_cfg);
}
--
2.49.0

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@ -6,7 +6,7 @@
Name: libvpx
Summary: VP8/VP9 Video Codec SDK
Version: 1.14.1
Release: 2%{?dist}
Release: 3%{?dist}
License: BSD-3-Clause
URL: http://www.webmproject.org/code/
Source0: https://github.com/webmproject/libvpx/archive/v%{version}.tar.gz
@ -23,6 +23,8 @@ BuildRequires: nasm
%endif
BuildRequires: doxygen, php-cli, perl(Getopt::Long)
Patch1: 0001-vpx_codec_enc_init_multi-fix-double-free-on-init-fai.patch
%description
libvpx provides the VP8/VP9 SDK, which allows you to integrate your applications
with the VP8 and VP9 video codecs, high quality, royalty free, open source codecs
@ -47,6 +49,7 @@ and decoder.
%prep
%setup -q -n libvpx-%{version}
%patch -P0 -p1 -b .fortify-source-on
%patch -P1 -p1 -b .0001
%build
@ -202,6 +205,10 @@ rm -rf %{buildroot}%{_prefix}/src
%{_bindir}/*
%changelog
* Tue Jun 03 2025 Wim Taymans <wtaymans@redhat.com> - 1.14.1-3
- Add patch for double free
Resolves: RHEL-93904
* Tue Oct 29 2024 Troy Dawson <tdawson@redhat.com> - 1.14.1-2
- Bump release for October 2024 mass rebuild:
Resolves: RHEL-64018