From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5681015C83 for ; Mon, 5 Dec 2022 19:33:15 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D1189C433D6; Mon, 5 Dec 2022 19:33:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1670268795; bh=uX9pye5y8zlsZPEPmAbioGWdQIZXZjdHpdgBNDIJKh0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sDmwvWjKn2FfJ1t3Ye/P+b0fov3ZxMUmz6FqnJmSfvwSALSxdtQn0VbBO6ysEhCsZ zgLPaW5M2/8HvIJaDy/zvbv0Tpb2nUvY8VQD3PcCJQ/SgYOGjc3S6f6i48Fiz6sHRX YjKV8VSdTUQSNf+kBGmAYklJMXPLSfjQYDIw8CPE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+f966c13b1b4fc0403b19@syzkaller.appspotmail.com, Yue Hu , Gao Xiang , Sasha Levin Subject: [PATCH 5.15 004/120] erofs: fix order >= MAX_ORDER warning due to crafted negative i_size Date: Mon, 5 Dec 2022 20:09:04 +0100 Message-Id: <20221205190806.676284261@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221205190806.528972574@linuxfoundation.org> References: <20221205190806.528972574@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Gao Xiang [ Upstream commit 1dd73601a1cba37a0ed5f89a8662c90191df5873 ] As syzbot reported [1], the root cause is that i_size field is a signed type, and negative i_size is also less than EROFS_BLKSIZ. As a consequence, it's handled as fast symlink unexpectedly. Let's fall back to the generic path to deal with such unusual i_size. [1] https://lore.kernel.org/r/000000000000ac8efa05e7feaa1f@google.com Reported-by: syzbot+f966c13b1b4fc0403b19@syzkaller.appspotmail.com Fixes: 431339ba9042 ("staging: erofs: add inode operations") Reviewed-by: Yue Hu Link: https://lore.kernel.org/r/20220909023948.28925-1-hsiangkao@linux.alibaba.com Signed-off-by: Gao Xiang Signed-off-by: Sasha Levin --- fs/erofs/inode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c index a552399e211d..0c293ff6697b 100644 --- a/fs/erofs/inode.c +++ b/fs/erofs/inode.c @@ -222,7 +222,7 @@ static int erofs_fill_symlink(struct inode *inode, void *data, /* if it cannot be handled with fast symlink scheme */ if (vi->datalayout != EROFS_INODE_FLAT_INLINE || - inode->i_size >= PAGE_SIZE) { + inode->i_size >= PAGE_SIZE || inode->i_size < 0) { inode->i_op = &erofs_symlink_iops; return 0; } -- 2.35.1