Thanks to fuzz testing, we can pass an invalid bytenr to extent buffer
via alloc_extent_buffer(). An unaligned eb can have more pages than it
should have, which ends up extent buffer's leak or some corrupted content
in extent buffer.
This adds a warning to let us quickly know what was happening.
Now that alloc_extent_buffer() no more returns NULL, this changes its
caller and callers of its caller to match with the new error
handling.
Signed-off-by: Liu Bo <bo.li....@oracle.com>
---
v2:
- Add more fine-grained error handling to alloc_extent_buffer() and
its callers
- Use btrfs_err and -EINVAL instead of WARN_ONCE().
fs/btrfs/ctree.c | 2 ++
fs/btrfs/disk-io.c | 8 ++++----
fs/btrfs/extent-tree.c | 10 ++++++----
fs/btrfs/extent_io.c | 15 ++++++++++++---
fs/btrfs/tree-log.c | 4 ++--
fs/btrfs/volumes.c | 4 ++--
6 files changed, 28 insertions(+), 15 deletions(-)
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 427c36b..24c9fb2 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -2510,6 +2510,8 @@ read_block_for_search(struct btrfs_trans_handle *trans,
if (!btrfs_buffer_uptodate(tmp, 0, 0))
ret = -EIO;
free_extent_buffer(tmp);
+ } else {
+ ret = PTR_ERR(tmp);
}
return ret;
}
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index ea78d77..c2a9cec 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1098,7 +1098,7 @@ void readahead_tree_block(struct btrfs_root *root, u64
bytenr)
struct inode *btree_inode = root->fs_info->btree_inode;
buf = btrfs_find_create_tree_block(root, bytenr);
- if (!buf)
+ if (IS_ERR(buf))
return;
read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
buf, 0, WAIT_NONE, btree_get_extent, 0);
@@ -1114,7 +1114,7 @@ int reada_tree_block_flagged(struct btrfs_root *root, u64
bytenr,
int ret;
buf = btrfs_find_create_tree_block(root, bytenr);
- if (!buf)
+ if (IS_ERR(buf))
return 0;
set_bit(EXTENT_BUFFER_READAHEAD, &buf->bflags);
@@ -1171,8 +1171,8 @@ struct extent_buffer *read_tree_block(struct btrfs_root
*root, u64 bytenr,
int ret;
buf = btrfs_find_create_tree_block(root, bytenr);
- if (!buf)
- return ERR_PTR(-ENOMEM);
+ if (IS_ERR(buf))
+ return buf;
ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
if (ret) {
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index a400951..d63eeee 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -8010,8 +8010,9 @@ btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *buf;
buf = btrfs_find_create_tree_block(root, bytenr);
- if (!buf)
- return ERR_PTR(-ENOMEM);
+ if (IS_ERR(buf))
+ return buf;
+
btrfs_set_header_generation(buf, trans->transid);
btrfs_set_buffer_lockdep_class(root->root_key.objectid, buf, level);
btrfs_tree_lock(buf);
@@ -8653,8 +8654,9 @@ static noinline int do_walk_down(struct
btrfs_trans_handle *trans,
next = btrfs_find_tree_block(root->fs_info, bytenr);
if (!next) {
next = btrfs_find_create_tree_block(root, bytenr);
- if (!next)
- return -ENOMEM;
+ if (IS_ERR(next))
+ return PTR_ERR(next);
+
btrfs_set_buffer_lockdep_class(root->root_key.objectid, next,
level - 1);
reada = 1;
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 6f38c2c..91c4d23 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -4883,18 +4883,25 @@ struct extent_buffer *alloc_extent_buffer(struct
btrfs_fs_info *fs_info,
int uptodate = 1;
int ret;
+ if (!IS_ALIGNED(start, fs_info->tree_root->sectorsize)) {
+ btrfs_err(fs_info, "bad tree block start %llu", start);
+ return ERR_PTR(-EINVAL);
+ }
+
eb = find_extent_buffer(fs_info, start);
if (eb)
return eb;
eb = __alloc_extent_buffer(fs_info, start, len);
if (!eb)
- return NULL;
+ return ERR_PTR(-ENOMEM);
for (i = 0; i < num_pages; i++, index++) {
p = find_or_create_page(mapping, index, GFP_NOFS|__GFP_NOFAIL);
- if (!p)
+ if (!p) {
+ exists = ERR_PTR(-ENOMEM);
goto free_eb;
+ }
spin_lock(&mapping->private_lock);
if (PagePrivate(p)) {
@@ -4939,8 +4946,10 @@ struct extent_buffer *alloc_extent_buffer(struct
btrfs_fs_info *fs_info,
set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
again:
ret = radix_tree_preload(GFP_NOFS);
- if (ret)
+ if (ret) {
+ exists = ERR_PTR(ret);
goto free_eb;
+ }
spin_lock(&fs_info->buffer_lock);
ret = radix_tree_insert(&fs_info->buffer_radix,
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index b7665af..c05f69a 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -2422,8 +2422,8 @@ static noinline int walk_down_log_tree(struct
btrfs_trans_handle *trans,
root_owner = btrfs_header_owner(parent);
next = btrfs_find_create_tree_block(root, bytenr);
- if (!next)
- return -ENOMEM;
+ if (IS_ERR(next))
+ return PTR_ERR(next);
if (*level == 1) {
ret = wc->process_func(root, next, wc, ptr_gen);
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 7a169de..d50a713 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -6597,8 +6597,8 @@ int btrfs_read_sys_array(struct btrfs_root *root)
* overallocate but we can keep it as-is, only the first page is used.
*/
sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET);
- if (!sb)
- return -ENOMEM;
+ if (IS_ERR(sb))
+ return PTR_ERR(sb);
set_extent_buffer_uptodate(sb);
btrfs_set_buffer_lockdep_class(root->root_key.objectid, sb, 0);
/*
--
2.5.5
--
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