erofs: fix potential overflow calculating xattr_isize

[ Upstream commit 1b3567a1969b26f709d82a874498c0754ea841c3 ]

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>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20230414061810.6479-1-jefflexu@linux.alibaba.com
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index 4868000..340bd56 100644 (file)
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -311,7 +311,7 @@ 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;