Re: [PATCH] fs/ntfs3: Don't clear upper bits accidentally in log_replay()

Namjae Jeon
2022-05-19T00:56:06Z

2022-05-09 18:03 GMT+09:00, Dan Carpenter <dan.carpenter@oracle.com>:
> The "vcn" variable is a 64 bit. The "log->clst_per_page" variable is a
> u32. This means that the mask accidentally clears out the high 32 bits
> when it was only supposed to clear some low bits. Fix this by adding a
> cast to u64.
>
> Fixes: b46acd6a6a62 ("fs/ntfs3: Add NTFS journal")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Namjae Jeon <linkinjeon@kernel.org>

> ---
> Why am I getting new Smatch warnings in old ntfs3 code? It is a mystery.
>
> fs/ntfs3/fslog.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/ntfs3/fslog.c b/fs/ntfs3/fslog.c
> index 915f42cf07bc..0da339fda2f4 100644
> --- a/fs/ntfs3/fslog.c
> +++ b/fs/ntfs3/fslog.c
> @@ -5057,7 +5057,7 @@ int log_replay(struct ntfs_inode *ni, bool
> *initialized)
> goto add_allocated_vcns;
>
> vcn = le64_to_cpu(lrh->target_vcn);
> - vcn &= ~(log->clst_per_page - 1);
> + vcn &= ~(u64)(log->clst_per_page - 1);
>
> add_allocated_vcns:
> for (i = 0, vcn = le64_to_cpu(lrh->target_vcn),
> --
> 2.35.1
>
>
>