On Wed, Oct 28, 2020 at 04:51:09PM -0400, Kyungtae Kim wrote: > We report a bug (in linux-5.8.13) found by FuzzUSB (a modified version > of syzkaller). > > The bug happened when accessing a freed instance of struct fsg_dev > (i.e., fsg->bulk_in) in do_set_interface() (line 2245). > > ================================================================== > BUG: KASAN: use-after-free in do_set_interface.part.7+0xa6b/0xd90 > drivers/usb/gadget/function/f_mass_storage.c:2245 > Read of size 8 at addr ffff88806bc940f8 by task file-storage/2063 > > CPU: 3 PID: 2063 Comm: file-storage Not tainted 5.8.13 #4 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:77 [inline] > dump_stack+0xa7/0xea lib/dump_stack.c:118 > print_address_description.constprop.8+0x3f/0x60 mm/kasan/report.c:383 > kasan_report.cold.11+0x20/0x37 mm/kasan/report.c:513 > __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:146 > do_set_interface.part.7+0xa6b/0xd90 > drivers/usb/gadget/function/f_mass_storage.c:2245 > do_set_interface drivers/usb/gadget/function/f_mass_storage.c:2202 [inline] > handle_exception drivers/usb/gadget/function/f_mass_storage.c:2426 [inline] > fsg_main_thread+0x12c7/0x59f1 drivers/usb/gadget/function/f_mass_storage.c:2466 > kthread+0x374/0x480 kernel/kthread.c:291 > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 Is this reproducible? Can you test patches? Alan Stern
