path: root/extent_io.c
diff options
authorSergei Trofimovich <>2011-06-04 11:19:21 +0300
committerChris Mason <>2011-10-25 09:18:58 -0400
commit8e4b7e883abfca81cd864808da729b2227cff34c (patch)
tree3f56df8b1dd5ef4d163edf2c316ceb68cd4f3efc /extent_io.c
parentf509f1762e054c3f9bd5e4321dce9240bfd5b03a (diff)
mkfs.btrfs: write zeroes instead on uninitialized data.
Found by valgrind: ==8968== Use of uninitialised value of size 8 ==8968== at 0x41CE7D: crc32c_le (crc32c.c:98) ==8968== by 0x40A1D0: csum_tree_block_size (disk-io.c:82) ==8968== by 0x40A2D4: csum_tree_block (disk-io.c:105) ==8968== by 0x40A7D6: write_tree_block (disk-io.c:241) ==8968== by 0x40ACEE: __commit_transaction (disk-io.c:354) ==8968== by 0x40AE9E: btrfs_commit_transaction (disk-io.c:385) ==8968== by 0x42CF66: make_image (mkfs.c:1061) ==8968== by 0x42DE63: main (mkfs.c:1410) ==8968== Uninitialised value was created by a stack allocation ==8968== at 0x42B5FB: add_inode_items (mkfs.c:493) 1. On-disk inode format has reserved (and thus, random at alloc time) fields: btrfs_inode_item: __le64 reserved[4] 2. Sometimes extents are created on disk without writing data there. (Or at least not all data is written there). Kernel code always had it kzalloc'ed. Zero them all. Signed-off-by: Sergei Trofimovich <> Signed-off-by: Hugo Mills <>
Diffstat (limited to 'extent_io.c')
1 files changed, 1 insertions, 0 deletions
diff --git a/extent_io.c b/extent_io.c
index 70fecbbf..8f0a8763 100644
--- a/extent_io.c
+++ b/extent_io.c
@@ -568,6 +568,7 @@ static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree,
return NULL;
+ memset(eb, 0, sizeof(struct extent_buffer) + blocksize);
eb->start = bytenr;
eb->len = blocksize;