linux-kernel - [PATCH] f2fs: fix to avoid using uninitialized variable

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Date:   Mon, 2 Mar 2020 17:34:27 +0800
From:   Chao Yu <yuchao0@...wei.com>
To:     <jaegeuk@...nel.org>
CC:     <linux-f2fs-devel@...ts.sourceforge.net>,
        <linux-kernel@...r.kernel.org>, <chao@...nel.org>,
        Chao Yu <yuchao0@...wei.com>
Subject: [PATCH] f2fs: fix to avoid using uninitialized variable

In f2fs_vm_page_mkwrite(), if inode is compress one, and current mmapped
page locates in compressed cluster, we have to call f2fs_get_dnode_of_data()
to get its physical block address before f2fs_wait_on_block_writeback().

Signed-off-by: Chao Yu <yuchao0@...wei.com>
---
 fs/f2fs/file.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 09164c6a1d39..caa7ca42791f 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -106,10 +106,18 @@ static vm_fault_t f2fs_vm_page_mkwrite(struct vm_fault *vmf)
 		err = f2fs_get_block(&dn, page->index);
 		f2fs_put_dnode(&dn);
 		__do_map_lock(sbi, F2FS_GET_BLOCK_PRE_AIO, false);
-		if (err) {
-			unlock_page(page);
-			goto out_sem;
-		}
+	}
+
+#ifdef CONFIG_F2FS_FS_COMPRESSION
+	if (!need_alloc) {
+		set_new_dnode(&dn, inode, NULL, NULL, 0);
+		err = f2fs_get_dnode_of_data(&dn, page->index, LOOKUP_NODE);
+		f2fs_put_dnode(&dn);
+	}
+#endif
+	if (err) {
+		unlock_page(page);
+		goto out_sem;
 	}
 
 	f2fs_wait_on_page_writeback(page, DATA, false, true);
-- 
2.18.0.rc1