From 7da6844cf7bc44dcda548a0a0aebf85f3a1c1485 Mon Sep 17 00:00:00 2001 From: Brian King Date: Tue, 12 Jul 2005 13:58:30 -0700 Subject: [PATCH] [PATCH] cdev: cdev_put oops While fixing an oops in the st driver in a dirty release path, I encountered an oops in cdev_put for cdevs allocated using cdev_alloc. If cdev_del is called when the cdev kobject still has an open user, when the last cdev_put is called, the cdev_put will call kobject_put, which will end up ultimately releasing the cdev in cdev_dynamic_release. Patch fixes the oops by preventing cdev_put from accessing freed memory. Signed-off-by: Brian King Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/char_dev.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/char_dev.c b/fs/char_dev.c index a69a5d8a406f..3b1b1eefdbb0 100644 --- a/fs/char_dev.c +++ b/fs/char_dev.c @@ -277,8 +277,9 @@ static struct kobject *cdev_get(struct cdev *p) void cdev_put(struct cdev *p) { if (p) { + struct module *owner = p->owner; kobject_put(&p->kobj); - module_put(p->owner); + module_put(owner); } } -- 2.20.1