From 0eeb12aef5ed18b3ecb5346440742971d5b11703 Mon Sep 17 00:00:00 2001 From: Qu Wenruo 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 Signed-off-by: Qu Wenruo Signed-off-by: David Sterba --- 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 89ccf073..f46f3267 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;