9p: Fix writeback fid incorrectly being attached to dentry

v9fs_dir_release needs fid->ilist to have been initialized for filp's
fid, not the inode's writeback fid's.

With refcounting this can be improved on later but this appears to fix
null deref issues.

Link: http://lkml.kernel.org/r/1605802012-31133-3-git-send-email-asmadeus@codewreck.org
Fixes: 6636b6dcc3 ("fs/9p: track open fids")
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
This commit is contained in:
Dominique Martinet 2020-11-19 15:11:04 +01:00
parent ff5e72ebef
commit 5bfe97d738

View File

@ -46,7 +46,7 @@ int v9fs_file_open(struct inode *inode, struct file *file)
int err;
struct v9fs_inode *v9inode;
struct v9fs_session_info *v9ses;
struct p9_fid *fid;
struct p9_fid *fid, *writeback_fid;
int omode;
p9_debug(P9_DEBUG_VFS, "inode: %p file: %p\n", inode, file);
@ -85,13 +85,13 @@ int v9fs_file_open(struct inode *inode, struct file *file)
* because we want write after unlink usecase
* to work.
*/
fid = v9fs_writeback_fid(file_dentry(file));
writeback_fid = v9fs_writeback_fid(file_dentry(file));
if (IS_ERR(fid)) {
err = PTR_ERR(fid);
mutex_unlock(&v9inode->v_mutex);
goto out_error;
}
v9inode->writeback_fid = (void *) fid;
v9inode->writeback_fid = (void *) writeback_fid;
}
mutex_unlock(&v9inode->v_mutex);
if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)