Re: [PATCH] erofs: fix potential overflow calculating xattr_isize

[Gao Xiang]

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 <jeffl...@linux.alibaba.com>

Thanks for catching this!
Reviewed-by: Gao Xiang <hsiang...@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;