From 6630036b7c228f57c7893ee0403e92c2db2cd21d Mon Sep 17 00:00:00 2001 From: Eric Van Hensbergen Date: Tue, 19 Mar 2024 13:50:32 +0000 Subject: fs/9p: fix uninitialized values during inode evict 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: syzbot+eb83fe1cce5833cd66a0@syzkaller.appspotmail.com Signed-off-by: Eric Van Hensbergen --- fs/9p/vfs_inode.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c index 360a5304ec03ce..b01b1bbf249371 100644 --- a/fs/9p/vfs_inode.c +++ b/fs/9p/vfs_inode.c @@ -344,17 +344,21 @@ void v9fs_evict_inode(struct inode *inode) struct v9fs_inode __maybe_unused *v9inode = V9FS_I(inode); __le32 __maybe_unused version; - truncate_inode_pages_final(&inode->i_data); + if (!is_bad_inode(inode)) { + truncate_inode_pages_final(&inode->i_data); - version = cpu_to_le32(v9inode->qid.version); - netfs_clear_inode_writeback(inode, &version); + version = cpu_to_le32(v9inode->qid.version); + netfs_clear_inode_writeback(inode, &version); - clear_inode(inode); - filemap_fdatawrite(&inode->i_data); + clear_inode(inode); + filemap_fdatawrite(&inode->i_data); #ifdef CONFIG_9P_FSCACHE - fscache_relinquish_cookie(v9fs_inode_cookie(v9inode), false); + if (v9fs_inode_cookie(v9inode)) + fscache_relinquish_cookie(v9fs_inode_cookie(v9inode), false); #endif + } else + clear_inode(inode); } struct inode *v9fs_fid_iget(struct super_block *sb, struct p9_fid *fid) -- cgit 1.2.3-korg