Commit a9f38063 authored by Eric Van Hensbergen's avatar Eric Van Hensbergen Committed by Long Li
Browse files

fs/9p: fix uninitialized values during inode evict 

mainline inclusion
from mainline-v6.9-rc1
commit 6630036b7c228f57c7893ee0403e92c2db2cd21d
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9U997
CVE: CVE-2024-36923

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=6630036b7c228f57c7893ee0403e92c2db2cd21d



--------------------------------

If an iget fails due to not being able to retrieve information
from the server then the inode structure is only partially
initialized.  When the inode gets evicted, references to
uninitialized structures (like fscache cookies) were being
made.

This patch checks for a bad_inode before doing anything other
than clearing the inode from the cache.  Since the inode is
bad, it shouldn't have any state associated with it that needs
to be written back (and there really isn't a way to complete
those anyways).

Reported-by: default avatar <syzbot+eb83fe1cce5833cd66a0@syzkaller.appspotmail.com>
Signed-off-by: default avatarEric Van Hensbergen <ericvh@kernel.org>

Conflicts:
	fs/9p/vfs_inode.c
[v9fs_evict_inode() function has been changed]
Signed-off-by: default avatarLong Li <leo.lilong@huawei.com>
parent a1125812

fs/9p/vfs_inode.c

+13 −9
Original line number Diff line number Diff line
@@ -376,6 +376,7 @@ void v9fs_evict_inode(struct inode *inode) 
{

	struct v9fs_inode *v9inode = V9FS_I(inode);



	if (!is_bad_inode(inode)) {

		truncate_inode_pages_final(&inode->i_data);

		clear_inode(inode);

		filemap_fdatawrite(&inode->i_data);
@@ -386,6 +387,9 @@ void v9fs_evict_inode(struct inode *inode) 
			p9_client_clunk(v9inode->writeback_fid);

			v9inode->writeback_fid = NULL;

		}

	} else {

		clear_inode(inode);

	}

}



static int v9fs_test_inode(struct inode *inode, void *data)