From c42791b6ec5453cd7910eac7bfdd88f27173f81c Mon Sep 17 00:00:00 2001
From: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Date: Wed, 18 Jan 2006 17:42:53 -0800
Subject: [PATCH] [PATCH] uml: make daemon transport behave properly
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@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---
arch/um/drivers/daemon_kern.c | 4 ++++
arch/um/drivers/daemon_user.c | 6 ++++++
2 files changed, 10 insertions(+)
diff --git a/arch/um/drivers/daemon_kern.c b/arch/um/drivers/daemon_kern.c
index 30d285b266af5..507e3cbac9d38 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, void *data)
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 1bb085b2824d1..c944265955e20 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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