From f74b86d85533a98ef7f573487af38f9dd514becb Mon Sep 17 00:00:00 2001 From: Filipe David Borba Manana Date: Tue, 21 Jan 2014 23:36:38 +0000 Subject: [PATCH] Btrfs: fix snprintf usage by send's gen_unique_name The buffer size argument passed to snprintf must account for the trailing null byte added by snprintf, and it returns a value >= then sizeof(buffer) when the string can't fit in the buffer. Since our buffer has a size of 64 characters, and the maximum orphan name we can generate is 63 characters wide, we must pass 64 as the buffer size to snprintf, and not 63. Signed-off-by: Filipe David Borba Manana Reviewed-by: David Sterba Signed-off-by: Josef Bacik Signed-off-by: Chris Mason --- fs/btrfs/send.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c index aa60cbe7066c..fc1f0abb8fe4 100644 --- a/fs/btrfs/send.c +++ b/fs/btrfs/send.c @@ -1336,7 +1336,7 @@ static int gen_unique_name(struct send_ctx *sctx, return -ENOMEM; while (1) { - len = snprintf(tmp, sizeof(tmp) - 1, "o%llu-%llu-%llu", + len = snprintf(tmp, sizeof(tmp), "o%llu-%llu-%llu", ino, gen, idx); if (len >= sizeof(tmp)) { /* should really not happen */ -- 2.11.0