Commit 461b43a8 authored Jul 01, 2021 by Eric Biggers

f2fs: report correct st_size for encrypted symlinks

The stat() family of syscalls report the wrong size for encrypted
symlinks, which has caused breakage in several userspace programs.

Fix this by calling fscrypt_symlink_getattr() after f2fs_getattr() for
encrypted symlinks. This function computes the correct size by reading
and decrypting the symlink target (if it's not already cached).

For more details, see the commit which added fscrypt_symlink_getattr().

Fixes: cbaf042a ("f2fs crypto: add symlink encryption")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210702065350.209646-4-ebiggers@kernel.org

Signed-off-by: Eric Biggers <ebiggers@google.com>

parent 8c4bca10

fs/f2fs/namei.c

+11 −1

Original line number	Diff line number	Diff line
		@@ -1323,9 +1323,19 @@ static const char f2fs_encrypted_get_link(struct dentry dentry,
		return target;
		}

		static int f2fs_encrypted_symlink_getattr(struct user_namespace *mnt_userns,
		const struct path *path,
		struct kstat *stat, u32 request_mask,
		unsigned int query_flags)
		{
		f2fs_getattr(mnt_userns, path, stat, request_mask, query_flags);

		return fscrypt_symlink_getattr(path, stat);
		}

		const struct inode_operations f2fs_encrypted_symlink_inode_operations = {
		.get_link = f2fs_encrypted_get_link,
		.getattr = f2fs_getattr,
		.getattr = f2fs_encrypted_symlink_getattr,
		.setattr = f2fs_setattr,
		.listxattr = f2fs_listxattr,
		};