btrfs-progs: error out immediately if an unknown backref type is found

(cherry picked from commit 77c42223277a6b225d3a7ce0ded0a907688b0639)

0009-btrfs-progs-error-out-immediately-if-an-unknown-back.patch

@@ -0,0 +1,42 @@
+From 0eeb12aef5ed18b3ecb5346440742971d5b11703 Mon Sep 17 00:00:00 2001
+From: Qu Wenruo <wqu@suse.com>
+Date: Tue, 4 Jun 2024 14:17:51 +0930
+Subject: [PATCH] btrfs-progs: error out immediately if an unknown backref type
+ is found
+
+There is a bug report that for fuzzed image
+bko-155621-bad-block-group-offset.raw, "btrfs check --mode=lowmem
+--repair" would lead to an endless loop.
+
+Unlike original mode, lowmem mode relies on the backref walk to properly
+go through each root, but unfortunately inside __add_inline_refs() we
+doesn't handle unknown backref types correctly, causing it never moving
+forward thus deadloop.
+
+Fix it by erroring out to prevent an endless loop.
+
+Issue: #788
+Reviewed-by: Josef Bacik <josef@toxicpanda.com>
+Signed-off-by: Qu Wenruo <wqu@suse.com>
+Signed-off-by: David Sterba <dsterba@suse.com>
+---
+ kernel-shared/backref.c | 3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+diff --git a/kernel-shared/backref.c b/kernel-shared/backref.c
+index d9e8d2f..6866d6d 100644
+--- a/kernel-shared/backref.c
++++ b/kernel-shared/backref.c
+@@ -650,7 +650,8 @@ static int __add_inline_refs(struct btrfs_fs_info *fs_info,
+ 			break;
+ 		}
+ 		default:
+-			WARN_ON(1);
++			error("invalid backref type: %u", type);
++			ret = -EUCLEAN;
+ 		}
+ 		if (ret)
+ 			return ret;
+-- 
+2.43.0
+

btrfs-progs.spec

@@ -1,6 +1,6 @@
 Name:       btrfs-progs
 Version:    6.6.3
-Release:    9
+Release:    10
 Summary:    btrfs userspace programs
 License:    GPLv2 and GPL+ and LGPL-2.1+ and GPL-3.0+ and LGPL-2.1 and MIT
 URL:        https://btrfs.wiki.kernel.org/index.php/Main_Page
@@ -14,6 +14,7 @@ Patch0005:  0005-btrfs-progs-fix-freeing-of-device-after-error-in-btr.patch
 Patch0006:  0006-fix-double-free-on-error-in-read_raid56.patch
 Patch0007:  0007-btrfs-progs-fi-show-canonicalize-path-when-using-blk.patch
 Patch0008:  0008-btrfs-progs-tune-fix-the-missing-close-of-filesystem.patch
+Patch0009:  0009-btrfs-progs-error-out-immediately-if-an-unknown-back.patch
 
 BuildRequires:  python3-devel >= 3.4
 BuildRequires:  libacl-devel, e2fsprogs-devel, libblkid-devel, libuuid-devel, zlib-devel, libzstd-devel, lzo-devel, systemd-devel
@@ -79,6 +80,9 @@ make mandir=%{_mandir} bindir=%{_sbindir} libdir=%{_libdir} incdir=%{_includedir
 %{_mandir}/man8/*.gz
 
 %changelog
+* Wed Jul 17 2024 liuh <liuhuan01@kylinos.cn> - 6.6.3-10
+- btrfs-progs: error out immediately if an unknown backref type is found
+
 * Tue Jul 2 2024 cenhuilin <cenhuilin@kylinos.cn> - 6.6.3-9
 - btrfs-progs: tune: fix the missing close() of filesystem fd