[PATCH 2/9] uml: make daemon transport behave properly

[Paolo 'Blaisorblade' Giarrusso]

From: Paolo 'Blaisorblade' Giarrusso <blaisorblade@xxxxxxxx>

Avoid uninitialized data in the daemon_data structure. I used this transport
before doing proper setup before-hand, and I got some very nice SLAB corruption
due to freeing crap pointers. So just make sure to clear everything when
appropriate.

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@xxxxxxxx>
---

 arch/um/drivers/daemon_kern.c |    4 ++++
 arch/um/drivers/daemon_user.c |    6 ++++++
 2 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/arch/um/drivers/daemon_kern.c b/arch/um/drivers/daemon_kern.c
index 30d285b..507e3cb 100644
--- a/arch/um/drivers/daemon_kern.c
+++ b/arch/um/drivers/daemon_kern.c
@@ -31,6 +31,10 @@ void daemon_init(struct net_device *dev,
 	dpri->fd = -1;
 	dpri->control = -1;
 	dpri->dev = dev;
+	/* We will free this pointer. If it contains crap we're burned. */
+	dpri->ctl_addr = NULL;
+	dpri->data_addr = NULL;
+	dpri->local_addr = NULL;
 
 	printk("daemon backend (uml_switch version %d) - %s:%s", 
 	       SWITCH_VERSION, dpri->sock_type, dpri->ctl_sock);
diff --git a/arch/um/drivers/daemon_user.c b/arch/um/drivers/daemon_user.c
index 1bb085b..c944265 100644
--- a/arch/um/drivers/daemon_user.c
+++ b/arch/um/drivers/daemon_user.c
@@ -158,10 +158,16 @@ static void daemon_remove(void *data)
 	struct daemon_data *pri = data;
 
 	os_close_file(pri->fd);
+	pri->fd = -1;
 	os_close_file(pri->control);
+	pri->control = -1;
+
 	kfree(pri->data_addr);
+	pri->data_addr = NULL;
 	kfree(pri->ctl_addr);
+	pri->ctl_addr = NULL;
 	kfree(pri->local_addr);
+	pri->local_addr = NULL;
 }
 
 int daemon_user_write(int fd, void *buf, int len, struct daemon_data *pri)

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