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authorEugene Teo <eugeneteo@kernel.sg>2008-02-09 10:53:17 -0500
committerRusty Russell <rusty@rustcorp.com.au>2008-03-10 18:35:56 -0400
commitf73d1e6ca6985b43a1871467463cba632fbc624d (patch)
tree84b01e87f41bf960c58b6934142da31f6d1638eb
parentcdeeeae056a429e729ae9e914fa8142ee45bee93 (diff)
lguest: make sure cpu is initialized before accessing it
If req is LHREQ_INITIALIZE, and the guest has been initialized before (unlikely), it will attempt to access cpu->tsk even though cpu is not yet initialized. Signed-off-by: Eugene Teo <eugeneteo@kernel.sg> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
-rw-r--r--drivers/lguest/lguest_user.c15
1 files changed, 8 insertions, 7 deletions
diff --git a/drivers/lguest/lguest_user.c b/drivers/lguest/lguest_user.c
index 85d42d3d01a9..2221485b0773 100644
--- a/drivers/lguest/lguest_user.c
+++ b/drivers/lguest/lguest_user.c
@@ -241,15 +241,16 @@ static ssize_t write(struct file *file, const char __user *in,
241 cpu = &lg->cpus[cpu_id]; 241 cpu = &lg->cpus[cpu_id];
242 if (!cpu) 242 if (!cpu)
243 return -EINVAL; 243 return -EINVAL;
244 }
245 244
246 /* Once the Guest is dead, all you can do is read() why it died. */ 245 /* Once the Guest is dead, you can only read() why it died. */
247 if (lg && lg->dead) 246 if (lg->dead)
248 return -ENOENT; 247 return -ENOENT;
249 248
250 /* If you're not the task which owns the Guest, you can only break */ 249 /* If you're not the task which owns the Guest, all you can do
251 if (lg && current != cpu->tsk && req != LHREQ_BREAK) 250 * is break the Launcher out of running the Guest. */
252 return -EPERM; 251 if (current != cpu->tsk && req != LHREQ_BREAK)
252 return -EPERM;
253 }
253 254
254 switch (req) { 255 switch (req) {
255 case LHREQ_INITIALIZE: 256 case LHREQ_INITIALIZE: