From 3952f84ed8428c4d10543ad458d68d779dcbc3c5 Mon Sep 17 00:00:00 2001 From: Filipe Manana Date: Tue, 21 Nov 2023 13:38:32 +0000 Subject: [PATCH] btrfs: fix off-by-one when checking chunk map includes logical address commit 5fba5a571858ce2d787fdaf55814e42725bfa895 upstream. At btrfs_get_chunk_map() we get the extent map for the chunk that contains the given logical address stored in the 'logical' argument. Then we do sanity checks to verify the extent map contains the logical address. One of these checks verifies if the extent map covers a range with an end offset behind the target logical address - however this check has an off-by-one error since it will consider an extent map whose start offset plus its length matches the target logical address as inclusive, while the fact is that the last byte it covers is behind the target logical address (by 1). So fix this condition by using '<=' rather than '<' when comparing the extent map's "start + length" against the target logical address. CC: stable@vger.kernel.org # 4.14+ Reviewed-by: Josef Bacik Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/volumes.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index c26d349..3200794 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -3050,7 +3050,7 @@ struct extent_map *btrfs_get_chunk_map(struct btrfs_fs_info *fs_info, return ERR_PTR(-EINVAL); } - if (em->start > logical || em->start + em->len < logical) { + if (em->start > logical || em->start + em->len <= logical) { btrfs_crit(fs_info, "found a bad mapping, wanted %llu-%llu, found %llu-%llu", logical, length, em->start, em->start + em->len); -- 2.7.4