On Wed, Feb 23, 2022 at 12:29:03PM +0100, gregkh@xxxxxxxxxxxxxxxxxxx wrote: > On Wed, Feb 23, 2022 at 11:17:07AM +0000, Zhang, Qiang1 wrote: > > > > syzbot has found a reproducer for the following issue on: > > > > HEAD commit: 4f12b742eb2b Merge tag 'nfs-for-5.17-3' of git://git.linux.. > > git tree: upstream > > console output: https://syzkaller.appspot.com/x/log.txt?x=110a6df2700000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=f6a069ed94a1ed1d > > dashboard link: https://syzkaller.appspot.com/bug?extid=348b571beb5eeb70a582 > > compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12377296700000 > > > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > > Reported-by: syzbot+348b571beb5eeb70a582@xxxxxxxxxxxxxxxxxxxxxxxxx > > > > ================================================================== > > BUG: KASAN: use-after-free in dev_uevent+0x712/0x780 drivers/base/core.c:2320 Read of size 8 at addr ffff88802b934098 by task udevd/3689 > > > > CPU: 2 PID: 3689 Comm: udevd Not tainted 5.17.0-rc4-syzkaller-00229-g4f12b742eb2b #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 Call Trace: > > <TASK> > > __dump_stack lib/dump_stack.c:88 [inline] > > dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 > > print_address_description.constprop.0.cold+0x8d/0x303 mm/kasan/report.c:255 __kasan_report mm/kasan/report.c:442 [inline] kasan_report.cold+0x83/0xdf mm/kasan/report.c:459 > > dev_uevent+0x712/0x780 drivers/base/core.c:2320 > > uevent_show+0x1b8/0x380 drivers/base/core.c:2391 > > dev_attr_show+0x4b/0x90 drivers/base/core.c:2094 If the uevent file being read was for the gadget rather than the udc, this should fix the problem. Alan Stern #syz test: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ v5.17-rc4 Index: usb-devel/drivers/usb/gadget/udc/core.c =================================================================== --- usb-devel.orig/drivers/usb/gadget/udc/core.c +++ usb-devel/drivers/usb/gadget/udc/core.c @@ -1436,7 +1436,6 @@ static void usb_gadget_remove_driver(str usb_gadget_udc_stop(udc); udc->driver = NULL; - udc->dev.driver = NULL; udc->gadget->dev.driver = NULL; } @@ -1498,7 +1497,6 @@ static int udc_bind_to_driver(struct usb driver->function); udc->driver = driver; - udc->dev.driver = &driver->driver; udc->gadget->dev.driver = &driver->driver; usb_gadget_udc_set_speed(udc, driver->max_speed); @@ -1521,7 +1519,6 @@ err1: dev_err(&udc->dev, "failed to start %s: %d\n", udc->driver->function, ret); udc->driver = NULL; - udc->dev.driver = NULL; udc->gadget->dev.driver = NULL; return ret; }
