| Message ID | 112cdf17-374f-fdc5-58ae-d8db3f695ac4@I-love.SAKURA.ne.jp (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] btrfs: Call btrfs_set_header_generation() before btrfs_clean_tree_block() | expand |
On Tue, Sep 20, 2022 at 10:43:51PM +0900, Tetsuo Handa wrote: > syzbot is reporting uninit-value in btrfs_clean_tree_block() [1], for > commit bc877d285ca3dba2 ("btrfs: Deduplicate extent_buffer init code") > missed that btrfs_set_header_generation() in btrfs_init_new_buffer() must > not be moved to after clean_tree_block() because clean_tree_block() is > calling btrfs_header_generation() since commit 55c69072d6bd5be1 ("Btrfs: > Fix extent_buffer usage when nodesize != leafsize"). > > Since memzero_extent_buffer() will reset "struct btrfs_header" part, we > can't move btrfs_set_header_generation() to before memzero_extent_buffer(). > Just re-add btrfs_set_header_generation() before btrfs_clean_tree_block(). > > Link: https://syzkaller.appspot.com/bug?extid=fba8e2116a12609b6c59 [1] > Reported-by: syzbot <syzbot+fba8e2116a12609b6c59@syzkaller.appspotmail.com> > Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> > Fixes: bc877d285ca3dba2 ("btrfs: Deduplicate extent_buffer init code") Added to misc-next, thanks.
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 6914cd8024ba..cfbbd7dc3c46 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -4888,6 +4888,9 @@ btrfs_init_new_buffer(struct btrfs_trans_handle *trans, struct btrfs_root *root, !test_bit(BTRFS_ROOT_RESET_LOCKDEP_CLASS, &root->state)) lockdep_owner = BTRFS_FS_TREE_OBJECTID; + /* btrfs_clean_tree_block() accesses generation field. */ + btrfs_set_header_generation(buf, trans->transid); + /* * This needs to stay, because we could allocate a freed block from an * old tree into a new tree, so we need to make sure this new block is
syzbot is reporting uninit-value in btrfs_clean_tree_block() [1], for commit bc877d285ca3dba2 ("btrfs: Deduplicate extent_buffer init code") missed that btrfs_set_header_generation() in btrfs_init_new_buffer() must not be moved to after clean_tree_block() because clean_tree_block() is calling btrfs_header_generation() since commit 55c69072d6bd5be1 ("Btrfs: Fix extent_buffer usage when nodesize != leafsize"). Since memzero_extent_buffer() will reset "struct btrfs_header" part, we can't move btrfs_set_header_generation() to before memzero_extent_buffer(). Just re-add btrfs_set_header_generation() before btrfs_clean_tree_block(). Link: https://syzkaller.appspot.com/bug?extid=fba8e2116a12609b6c59 [1] Reported-by: syzbot <syzbot+fba8e2116a12609b6c59@syzkaller.appspotmail.com> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Fixes: bc877d285ca3dba2 ("btrfs: Deduplicate extent_buffer init code") --- Changes in v2: Don't remove btrfs_set_header_generation() after memzero_extent_buffer(), pointed out by Johannes Thumshirn <Johannes.Thumshirn@wdc.com>. fs/btrfs/extent-tree.c | 3 +++ 1 file changed, 3 insertions(+)