4.19-stable review patch. If anyone has any objections, please let me know.
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From: Filipe Manana fdmanana@suse.com
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 josef@toxicpanda.com Signed-off-by: Filipe Manana fdmanana@suse.com Reviewed-by: David Sterba dsterba@suse.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/btrfs/volumes.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -2760,7 +2760,7 @@ static struct extent_map *get_chunk_map( 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);