Re: [PATCH] qnx4: add upcasting to avoid overflow

[Анастасия Любимова]

Just a friendly reminder.

23/11/23 13:06, Anastasia Belova пишет:
> To avoid possible integer overflow in qnx4_statfs
> cast literal to unsigned long. Otherwise multiplication
> of two u32 may give a value that is outside of the range.
>
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
>
> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
> Signed-off-by: Anastasia Belova <abelova@xxxxxxxxxxxxx>
> ---
>   fs/qnx4/inode.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/qnx4/inode.c b/fs/qnx4/inode.c
> index 6eb9bb369b57..4be8dba60567 100644
> --- a/fs/qnx4/inode.c
> +++ b/fs/qnx4/inode.c
> @@ -133,7 +133,7 @@ static int qnx4_statfs(struct dentry *dentry, struct kstatfs *buf)
>   
>   	buf->f_type    = sb->s_magic;
>   	buf->f_bsize   = sb->s_blocksize;
> -	buf->f_blocks  = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size) * 8;
> +	buf->f_blocks  = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size) * 8ul;
>   	buf->f_bfree   = qnx4_count_free_blocks(sb);
>   	buf->f_bavail  = buf->f_bfree;
>   	buf->f_namelen = QNX4_NAME_MAX;