From 5cdf7d5be8443ba0e14a5cfe551c59f931983647 Mon Sep 17 00:00:00 2001 From: Lubomir Rintel Date: Thu, 27 Mar 2014 08:09:21 +0100 Subject: [PATCH] usb: gadget: gadgetfs: Initialize CHIP to NULL before UDC probe Otherwise the value from the last probe would be retained that possibly is freed since (the UDC is removed) and therefore no longer relevant. Reproducible with the dummy UDC: modprobe dummy_hcd mount -t gadgetfs gadgetfs /dev/gadget umount /dev/gadget rmmod dummy_hcd mount -t gadgetfs gadgetfs /dev/gadget BUG: unable to handle kernel paging request at ffffffffa066fd9d Call Trace: [] ? d_alloc_name+0x22/0x50 [] ? selinux_d_instantiate+0x1c/0x20 [] gadgetfs_create_file+0x27/0xa0 [gadgetfs] [] ? setup_req.isra.4+0x80/0x80 [gadgetfs] [] gadgetfs_fill_super+0x13c/0x180 [gadgetfs] [] mount_single+0x92/0xc0 [] gadgetfs_mount+0x18/0x20 [gadgetfs] [] mount_fs+0x39/0x1b0 [] ? __alloc_percpu+0x10/0x20 [] vfs_kern_mount+0x63/0xf0 [] do_mount+0x23e/0xac0 [] ? strndup_user+0x4b/0xf0 [] SyS_mount+0x83/0xc0 [] system_call_fastpath+0x16/0x1b Signed-off-by: Lubomir Rintel Signed-off-by: Felipe Balbi --- drivers/usb/gadget/inode.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/usb/gadget/inode.c b/drivers/usb/gadget/inode.c index b5be6f0308c2..a925d0cbcd41 100644 --- a/drivers/usb/gadget/inode.c +++ b/drivers/usb/gadget/inode.c @@ -2043,6 +2043,7 @@ gadgetfs_fill_super (struct super_block *sb, void *opts, int silent) return -ESRCH; /* fake probe to determine $CHIP */ + CHIP = NULL; usb_gadget_probe_driver(&probe_driver); if (!CHIP) return -ENODEV; -- 2.34.1