From 8583b613095a46b000e5ee333d6bf58cad0c2248 Mon Sep 17 00:00:00 2001 From: Chandan Rajendra Date: Thu, 8 Dec 2016 19:26:19 +0530 Subject: [PATCH] btrfs-progs: convert: Prevent accounting blocks beyond end of device When looping across data block bitmap, __ext2_add_one_block() may add blocks which do not exist on the underlying disk. This commit prevents this from happening by checking the block index against the maximum block count that was present in the ext4 filesystem instance that is being converted. Signed-off-by: Chandan Rajendra Reviewed-by: Qu Wenruo Signed-off-by: David Sterba --- convert/main.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/convert/main.c b/convert/main.c index 4b4cea42..1148a369 100644 --- a/convert/main.c +++ b/convert/main.c @@ -1525,6 +1525,9 @@ static int __ext2_add_one_block(ext2_filsys fs, char *bitmap, offset /= EXT2FS_CLUSTER_RATIO(fs); offset += group_nr * EXT2_CLUSTERS_PER_GROUP(fs->super); for (i = 0; i < EXT2_CLUSTERS_PER_GROUP(fs->super); i++) { + if ((i + offset) >= ext2fs_blocks_count(fs->super)) + break; + if (ext2fs_test_bit(i, bitmap)) { u64 start;