Given on-disk i_xattr_icount is 16 bits and xattr_isize is calculated
from i_xattr_icount multiplying 4, xattr_isize has a theoretical maximum
of 256K (64K * 4).

Thus declare xattr_isize as unsigned int to avoid the potential overflow.

Fixes: bfb8674dc044 ("staging: erofs: add erofs in-memory stuffs")
Signed-off-by: Jingbo Xu <jefflexu@linux.alibaba.com>
---
 fs/erofs/internal.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index 8a563374b518..c86241a32ab3 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -306,7 +306,7 @@ struct erofs_inode {
 
 	unsigned char datalayout;
 	unsigned char inode_isize;
-	unsigned short xattr_isize;
+	unsigned int xattr_isize;
 
 	unsigned int xattr_shared_count;
 	unsigned int *xattr_shared_xattrs;
-- 
2.19.1.6.gb485710b

On 2023/4/14 14:18, Jingbo Xu wrote:
> Given on-disk i_xattr_icount is 16 bits and xattr_isize is calculated
> from i_xattr_icount multiplying 4, xattr_isize has a theoretical maximum
> of 256K (64K * 4).
> 
> Thus declare xattr_isize as unsigned int to avoid the potential overflow.
> 
> Fixes: bfb8674dc044 ("staging: erofs: add erofs in-memory stuffs")
> Signed-off-by: Jingbo Xu <jefflexu@linux.alibaba.com>

Good catch!

Reviewed-by: Chao Yu <chao@kernel.org>

Thanks,

On 2023/4/14 14:18, Jingbo Xu wrote:
> Given on-disk i_xattr_icount is 16 bits and xattr_isize is calculated
> from i_xattr_icount multiplying 4, xattr_isize has a theoretical maximum
> of 256K (64K * 4).
> 
> Thus declare xattr_isize as unsigned int to avoid the potential overflow.
> 
> Fixes: bfb8674dc044 ("staging: erofs: add erofs in-memory stuffs")
> Signed-off-by: Jingbo Xu <jefflexu@linux.alibaba.com>

Thanks for catching this!
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>

Thanks,
Gao Xiang

> ---
>   fs/erofs/internal.h | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
> index 8a563374b518..c86241a32ab3 100644
> --- a/fs/erofs/internal.h
> +++ b/fs/erofs/internal.h
> @@ -306,7 +306,7 @@ struct erofs_inode {
>   
>   	unsigned char datalayout;
>   	unsigned char inode_isize;
> -	unsigned short xattr_isize;
> +	unsigned int xattr_isize;
>   
>   	unsigned int xattr_shared_count;
>   	unsigned int *xattr_shared_xattrs;