The patch below does not apply to the 5.3-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From ee45197c807895e156b2be0abcaebdfc116487c8 Mon Sep 17 00:00:00 2001

From: Gao Xiang gaoxiang25@huawei.com Date: Mon, 19 Aug 2019 18:34:21 +0800 Subject: [PATCH] staging: erofs: some compressed cluster should be submitted for corrupted images

As reported by erofs_utils fuzzer, a logical page can belong to at most 2 compressed clusters, if one compressed cluster is corrupted, but the other has been ready in submitting chain.

The chain needs to submit anyway in order to keep the page working properly (page unlocked with PG_error set, PG_uptodate not set).

Let's fix it now.

Fixes: 3883a79abd02 ("staging: erofs: introduce VLE decompression support") Cc: stable@vger.kernel.org # 4.19+ Signed-off-by: Gao Xiang gaoxiang25@huawei.com Reviewed-by: Chao Yu yuchao0@huawei.com Link: https://lore.kernel.org/r/20190819103426.87579-2-gaoxiang25@huawei.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

diff --git a/drivers/staging/erofs/zdata.c b/drivers/staging/erofs/zdata.c index 2d7aaf98f7de..87b0c96caf8f 100644 --- a/drivers/staging/erofs/zdata.c +++ b/drivers/staging/erofs/zdata.c @@ -1307,19 +1307,18 @@ static int z_erofs_vle_normalaccess_readpage(struct file *file, err = z_erofs_do_read_page(&f, page, &pagepool); (void)z_erofs_collector_end(&f.clt);

- if (err) { + /* if some compressed cluster ready, need submit them anyway */ + z_erofs_submit_and_unzip(inode->i_sb, &f.clt, &pagepool, true); + + if (err) errln("%s, failed to read, err [%d]", __func__, err); - goto out; - }

- z_erofs_submit_and_unzip(inode->i_sb, &f.clt, &pagepool, true); -out: if (f.map.mpage) put_page(f.map.mpage);

/* clean up the remaining free pages */ put_pages_list(&pagepool); - return 0; + return err; }

static bool should_decompress_synchronously(struct erofs_sb_info *sbi,