This is a note to let you know that I've just added the patch titled
staging: erofs: fix an error handling in erofs_readdir()
to my staging git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git in the staging-next branch.
The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)
The patch will also be merged in the next major kernel release during the merge window.
If you have any questions about this process, please let me know.
From acb383f1dcb4f1e79b66d4be3a0b6f519a957b0d Mon Sep 17 00:00:00 2001
From: Gao Xiang gaoxiang25@huawei.com Date: Sun, 18 Aug 2019 20:54:57 +0800 Subject: staging: erofs: fix an error handling in erofs_readdir()
Richard observed a forever loop of erofs_read_raw_page() [1] which can be generated by forcely setting ->u.i_blkaddr to 0xdeadbeef (as my understanding block layer can handle access beyond end of device correctly).
After digging into that, it seems the problem is highly related with directories and then I found the root cause is an improper error handling in erofs_readdir().
Let's fix it now.
[1] https://lore.kernel.org/r/1163995781.68824.1566084358245.JavaMail.zimbra@nod...
Reported-by: Richard Weinberger richard@nod.at Fixes: 3aa8ec716e52 ("staging: erofs: add directory operations") Cc: stable@vger.kernel.org # 4.19+ Reviewed-by: Chao Yu yuchao0@huawei.com Signed-off-by: Gao Xiang gaoxiang25@huawei.com Link: https://lore.kernel.org/r/20190818125457.25906-1-hsiangkao@aol.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/staging/erofs/dir.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/drivers/staging/erofs/dir.c b/drivers/staging/erofs/dir.c index 5f38382637e6..77ef856df9f3 100644 --- a/drivers/staging/erofs/dir.c +++ b/drivers/staging/erofs/dir.c @@ -82,8 +82,15 @@ static int erofs_readdir(struct file *f, struct dir_context *ctx) unsigned int nameoff, maxsize;
dentry_page = read_mapping_page(mapping, i, NULL); - if (IS_ERR(dentry_page)) - continue; + if (dentry_page == ERR_PTR(-ENOMEM)) { + err = -ENOMEM; + break; + } else if (IS_ERR(dentry_page)) { + errln("fail to readdir of logical block %u of nid %llu", + i, EROFS_V(dir)->nid); + err = -EFSCORRUPTED; + break; + }
de = (struct erofs_dirent *)kmap(dentry_page);