fuse: avoid out-of-scope stack access

The all pointers within fuse_req must point to valid memory once
fuse_force_forget() returns.

This bug appeared in "fuse: implement NFS-like readdirplus support"
and was never in any official Linux release.

I tested the fuse_force_forget() code path by injecting to fake -ENOMEM and
verified the FORGET operation was called properly in userspace.

Signed-off-by: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
This commit is contained in:
Eric Wong 2013-02-04 13:04:44 +00:00 committed by Miklos Szeredi
parent 23c153e541
commit 6a4e922c3d
1 changed files with 10 additions and 3 deletions

View File

@ -440,9 +440,8 @@ __acquires(fc->lock)
}
}
void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
static void __fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
{
req->isreply = 1;
spin_lock(&fc->lock);
if (!fc->connected)
req->out.h.error = -ENOTCONN;
@ -459,6 +458,12 @@ void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
}
spin_unlock(&fc->lock);
}
void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
{
req->isreply = 1;
__fuse_request_send(fc, req);
}
EXPORT_SYMBOL_GPL(fuse_request_send);
static void fuse_request_send_nowait_locked(struct fuse_conn *fc,
@ -541,7 +546,9 @@ void fuse_force_forget(struct file *file, u64 nodeid)
req->in.args[0].size = sizeof(inarg);
req->in.args[0].value = &inarg;
req->isreply = 0;
fuse_request_send_nowait(fc, req);
__fuse_request_send(fc, req);
/* ignore errors */
fuse_put_request(fc, req);
}
/*