From 71f220034d0ae99d398423ab27e78847e5c02f09 Mon Sep 17 00:00:00 2001 From: David Sterba Date: Tue, 29 Nov 2016 16:07:19 +0100 Subject: [PATCH] btrfs-progs: receive: properly detect end of stream conditions Read buffer helper mistakenly reported end of data as an error. Next, we have to check if the first stream exists as an empty file is not a valid stream. Reported-by: Tsutomu Itoh Signed-off-by: David Sterba --- cmds-receive.c | 9 +++++++++ send-stream.c | 2 +- 2 files changed, 10 insertions(+), 1 deletion(-) diff --git a/cmds-receive.c b/cmds-receive.c index 62a79850..781dce9b 100644 --- a/cmds-receive.c +++ b/cmds-receive.c @@ -1061,6 +1061,7 @@ static int do_receive(struct btrfs_receive *r, const char *tomnt, char *dest_dir_full_path; char root_subvol_path[PATH_MAX]; int end = 0; + int count; dest_dir_full_path = realpath(tomnt, NULL); if (!dest_dir_full_path) { @@ -1155,6 +1156,7 @@ static int do_receive(struct btrfs_receive *r, const char *tomnt, if (ret < 0) goto out; + count = 0; while (!end) { if (r->cached_capabilities_len) { if (g_verbose >= 3) @@ -1169,6 +1171,13 @@ static int do_receive(struct btrfs_receive *r, const char *tomnt, max_errors); if (ret < 0) goto out; + /* Empty stream is invalid */ + if (ret && count == 0) { + error("empty stream is not considered valid"); + ret = -EINVAL; + goto out; + } + count++; if (ret) end = 1; diff --git a/send-stream.c b/send-stream.c index 920c7420..5a028cd9 100644 --- a/send-stream.c +++ b/send-stream.c @@ -74,7 +74,7 @@ static int read_buf(struct btrfs_send_stream *sctx, char *buf, size_t len) ret = 0; out_eof: - if (pos < len) { + if (0 < pos && pos < len) { error("short read from stream: expected %zu read %zu", len, pos); ret = -EIO; } else {