Re: [Qemu-devel] [PATCH] block/blklogwrites: Make sure the log sector size is not too small

[Ari Sundholm]

Would there be a chance of getting this included in 3.0?

On 07/06/2018 03:00 PM, Ari Sundholm wrote:
> The sector size needs to be large enough to accommodate the data
> structures for the log super block and log write entries. This was
> previously not properly checked, which made it possible to cause
> QEMU to badly misbehave.
>
> Signed-off-by: Ari Sundholm <address@hidden>
> ---
>   block/blklogwrites.c | 5 ++++-
>   1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/block/blklogwrites.c b/block/blklogwrites.c
> index 63bf6b3..efa2c7a 100644
> --- a/block/blklogwrites.c
> +++ b/block/blklogwrites.c
> @@ -89,7 +89,10 @@ static inline uint32_t blk_log_writes_log2(uint32_t value)
>   
>   static inline bool blk_log_writes_sector_size_valid(uint32_t sector_size)
>   {
> -    return sector_size < (1ull << 24) && is_power_of_2(sector_size);
> +    return is_power_of_2(sector_size) &&
> +        sector_size >= sizeof(struct log_write_super) &&
> +        sector_size >= sizeof(struct log_write_entry) &&
> +        sector_size < (1ull << 24);
>   }
>   
>   static uint64_t blk_log_writes_find_cur_log_sector(BdrvChild *log,