Re: [PATCH 3/3] ubifs: check node hash calculation errors

[Zhihao Cheng]

在 2026/11/2 20:14, shao.mingyin@xxxxxxxxxx 写道:
> ubifs_node_calc_hash() can fail when authentication is enabled and the
> crypto operation fails.  Five calls ignore the return value and use the
> uninitialized stack buffer as the node hash: replay_bud() stores it in
> the replay entry, make_idx_node() and write_index() copy it into the
> parent branch or the index root, and create_default_filesystem() copies
> it into an index branch and into the master node.  Verifying those nodes
> later then fails with a hash mismatch.
>
> Propagate the error from all five call sites.
>
> Fixes: 16a26b20d2af ("ubifs: authentication: Add hashes to index nodes")
> Fixes: 104115a3eb54 ("ubifs: Add hashes and HMACs to default filesystem")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Shao Mingyin <shao.mingyin@xxxxxxxxxx>
Reviewed-by: Zhihao Cheng <chengzhihao1@xxxxxxxxxx>
> ---
> diff --git a/fs/ubifs/replay.c b/fs/ubifs/replay.c
> index 263045e05cf1..442493dc18c6 100644
> --- a/fs/ubifs/replay.c
> +++ b/fs/ubifs/replay.c
> @@ -730,7 +730,9 @@ static int replay_bud(struct ubifs_info *c, struct bud_entry *b)
>   			goto out_dump;
>   		}
>
> -		ubifs_node_calc_hash(c, snod->node, hash);
> +		err = ubifs_node_calc_hash(c, snod->node, hash);
> +		if (err)
> +			goto out;
>
>   		if (snod->sqnum > c->max_sqnum)
>   			c->max_sqnum = snod->sqnum;
> diff --git a/fs/ubifs/sb.c b/fs/ubifs/sb.c
> index e7693b94e5b5..1c176be261e0 100644
> --- a/fs/ubifs/sb.c
> +++ b/fs/ubifs/sb.c
> @@ -329,14 +329,18 @@ static int create_default_filesystem(struct ubifs_info *c)
>   	if (err)
>   		goto out;
>
> -	ubifs_node_calc_hash(c, ino, hash);
> +	err = ubifs_node_calc_hash(c, ino, hash);
> +	if (err)
> +		goto out;
>   	ubifs_copy_hash(c, hash, ubifs_branch_hash(c, br));
>
>   	err = ubifs_write_node(c, idx, idx_node_size, main_first + DEFAULT_IDX_LEB, 0);
>   	if (err)
>   		goto out;
>
> -	ubifs_node_calc_hash(c, idx, hash);
> +	err = ubifs_node_calc_hash(c, idx, hash);
> +	if (err)
> +		goto out;
>   	ubifs_copy_hash(c, hash, mst->hash_root_idx);
>
>   	err = ubifs_write_node_hmac(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM, 0,
> diff --git a/fs/ubifs/tnc_commit.c b/fs/ubifs/tnc_commit.c
> index 7bf2672062a2..1a62739c3731 100644
> --- a/fs/ubifs/tnc_commit.c
> +++ b/fs/ubifs/tnc_commit.c
> @@ -52,7 +52,9 @@ static int make_idx_node(struct ubifs_info *c, struct ubifs_idx_node *idx,
>   		}
>   	}
>   	ubifs_prepare_node(c, idx, len, 0);
> -	ubifs_node_calc_hash(c, idx, hash);
> +	err = ubifs_node_calc_hash(c, idx, hash);
> +	if (err)
> +		return err;
>
>   	znode->lnum = lnum;
>   	znode->offs = offs;
> @@ -887,7 +889,9 @@ static int write_index(struct ubifs_info *c)
>   		}
>   		len = ubifs_idx_node_sz(c, znode->child_cnt);
>   		ubifs_prepare_node(c, idx, len, 0);
> -		ubifs_node_calc_hash(c, idx, hash);
> +		err = ubifs_node_calc_hash(c, idx, hash);
> +		if (err)
> +			return err;
>
>   		mutex_lock(&c->tnc_mutex);
> .