From: "Du, Changbin" <changbin.du@xxxxxxxxx> If acm_bind fails before allocate notification and acm->notify_req is not set to NULL after freed last time, double free will happen. kernel BUG at mm/slub.c:3392! invalid opcode: 0000 [#1] PREEMPT SMP EIP is at kfree+0x172/0x180 Call Trace: [<80c0e3b6>] ? usb_ep_autoconfig_ss+0x86/0x170 [<80c13345>] gs_free_req+0x15/0x30 [<80c12df1>] acm_bind+0x1c1/0x2d0 [<80c0e9be>] usb_add_function+0x6e/0x120 [<80c213cb>] acm_function_bind_config+0x2b/0x90 Signed-off-by: Du, Changbin <changbin.du@xxxxxxxxx> --- drivers/usb/gadget/function/f_acm.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/usb/gadget/function/f_acm.c b/drivers/usb/gadget/function/f_acm.c index 2fa1e80..e10c8d4 100644 --- a/drivers/usb/gadget/function/f_acm.c +++ b/drivers/usb/gadget/function/f_acm.c @@ -699,8 +699,10 @@ acm_bind(struct usb_configuration *c, struct usb_function *f) return 0; fail: - if (acm->notify_req) + if (acm->notify_req) { gs_free_req(acm->notify, acm->notify_req); + acm->notify_req = NULL; + } ERROR(cdev, "%s/%p: can't bind, err %d\n", f->name, f, status); @@ -713,8 +715,10 @@ static void acm_unbind(struct usb_configuration *c, struct usb_function *f) acm_string_defs[0].id = 0; usb_free_all_descriptors(f); - if (acm->notify_req) + if (acm->notify_req) { gs_free_req(acm->notify, acm->notify_req); + acm->notify_req = NULL; + } } static void acm_free_func(struct usb_function *f) -- 2.5.0 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html