> On Fri, Dec 25, 2020 at 12:05:22PM -0800, syzbot wrote: >> Hello, >> >> syzbot found the following issue on: >> >> HEAD commit: e37b12e4 Merge tag 'for-linus-5.11-ofs1' of git://git.kern.. >> git tree: upstream >> console output: https://syzkaller.appspot.com/x/log.txt?x=17429937500000 >> kernel config: https://syzkaller.appspot.com/x/.config?x=98408202fed1f636 >> dashboard link: https://syzkaller.appspot.com/bug?extid=5925509f78293baa7331 >> compiler: gcc (GCC) 10.1.0-syz 20200507 >> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1781fc5b500000 >> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=157cd123500000 >> >> The issue was bisected to: >> >> commit 8442b02bf3c6770e0d7e7ea17be36c30e95987b6 >> Author: Andrey Konovalov <andreyknvl@xxxxxxxxxx> >> Date: Mon Oct 21 14:20:58 2019 +0000 >> >> USB: dummy-hcd: increase max number of devices to 32 >> >> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1631d0db500000 >> final oops: https://syzkaller.appspot.com/x/report.txt?x=1531d0db500000 >> console output: https://syzkaller.appspot.com/x/log.txt?x=1131d0db500000 >> >> IMPORTANT: if you fix the issue, please add the following tag to the commit: >> Reported-by: syzbot+5925509f78293baa7331@xxxxxxxxxxxxxxxxxxxxxxxxx >> Fixes: 8442b02bf3c6 ("USB: dummy-hcd: increase max number of devices to 32") >> >> ================================================================================ >> UBSAN: shift-out-of-bounds in drivers/usb/gadget/udc/dummy_hcd.c:2293:33 >> shift exponent 257 is too large for 32-bit type 'int' >> CPU: 0 PID: 8526 Comm: syz-executor949 Not tainted 5.10.0-syzkaller #0 >> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 >> Call Trace: >> __dump_stack lib/dump_stack.c:79 [inline] >> dump_stack+0x107/0x163 lib/dump_stack.c:120 >> ubsan_epilogue+0xb/0x5a lib/ubsan.c:148 >> __ubsan_handle_shift_out_of_bounds.cold+0xb1/0x181 lib/ubsan.c:395 >> dummy_hub_control.cold+0x1a/0xbc drivers/usb/gadget/udc/dummy_hcd.c:2293 >> rh_call_control drivers/usb/core/hcd.c:683 [inline] >> rh_urb_enqueue drivers/usb/core/hcd.c:841 [inline] >> usb_hcd_submit_urb+0xcaa/0x22d0 drivers/usb/core/hcd.c:1544 >> usb_submit_urb+0x6e4/0x1560 drivers/usb/core/urb.c:585 >> usb_start_wait_urb+0x101/0x4c0 drivers/usb/core/message.c:58 >> usb_internal_control_msg drivers/usb/core/message.c:102 [inline] >> usb_control_msg+0x31c/0x4a0 drivers/usb/core/message.c:153 >> do_proc_control+0x4cb/0x9c0 drivers/usb/core/devio.c:1165 >> proc_control drivers/usb/core/devio.c:1191 [inline] >> usbdev_do_ioctl drivers/usb/core/devio.c:2535 [inline] >> usbdev_ioctl+0x12c1/0x3b20 drivers/usb/core/devio.c:2708 >> vfs_ioctl fs/ioctl.c:48 [inline] >> __do_sys_ioctl fs/ioctl.c:753 [inline] >> __se_sys_ioctl fs/ioctl.c:739 [inline] >> __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739 >> do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 >> entry_SYSCALL_64_after_hwframe+0x44/0xa9 >> RIP: 0033:0x443f29 >> Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 fb d7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 >> RSP: 002b:00007ffc10df4328 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 >> RAX: ffffffffffffffda RBX: 00000000004002e0 RCX: 0000000000443f29 >> RDX: 0000000020000000 RSI: 00000000c0185500 RDI: 0000000000000003 >> RBP: 00000000006ce018 R08: 0000000000000000 R09: 00000000004002e0 >> R10: 000000000000000f R11: 0000000000000246 R12: 0000000000401bb0 >> R13: 0000000000401c40 R14: 0000000000000000 R15: 0000000000000000 >> ================================================================================ > > The cause is pretty obvious. dummy-hcd assumes that requests sent to > the root hub are always valid, which isn't always true when they come > from userspace. > > Alan Stern > > #syz test: upstream e37b12e4 "upstream" does not look like a valid git repo address. > > Index: usb-devel/drivers/usb/gadget/udc/dummy_hcd.c > =================================================================== > --- usb-devel.orig/drivers/usb/gadget/udc/dummy_hcd.c > +++ usb-devel/drivers/usb/gadget/udc/dummy_hcd.c > @@ -2114,9 +2114,21 @@ static int dummy_hub_control( > dum_hcd->port_status &= ~USB_PORT_STAT_POWER; > set_link_state(dum_hcd); > break; > - default: > + case USB_PORT_FEAT_ENABLE: > + case USB_PORT_FEAT_C_ENABLE: > + case USB_PORT_FEAT_C_SUSPEND: > + /* Not allowed for USB-3 */ > + if (hcd->speed == HCD_USB3) > + goto error; > + fallthrough; > + case USB_PORT_FEAT_C_CONNECTION: > + case USB_PORT_FEAT_C_RESET: > dum_hcd->port_status &= ~(1 << wValue); > set_link_state(dum_hcd); > + break; > + default: > + /* Disallow INDICATOR and C_OVER_CURRENT */ > + goto error; > } > break; > case GetHubDescriptor: > @@ -2277,18 +2289,17 @@ static int dummy_hub_control( > */ > dum_hcd->re_timeout = jiffies + msecs_to_jiffies(50); > fallthrough; > + case USB_PORT_FEAT_C_CONNECTION: > + case USB_PORT_FEAT_C_RESET: > + case USB_PORT_FEAT_C_ENABLE: > + case USB_PORT_FEAT_C_SUSPEND: > + /* Not allowed for USB-3, and ignored for USB-2 */ > + if (hcd->speed == HCD_USB3) > + goto error; > + break; > default: > - if (hcd->speed == HCD_USB3) { > - if ((dum_hcd->port_status & > - USB_SS_PORT_STAT_POWER) != 0) { > - dum_hcd->port_status |= (1 << wValue); > - } > - } else > - if ((dum_hcd->port_status & > - USB_PORT_STAT_POWER) != 0) { > - dum_hcd->port_status |= (1 << wValue); > - } > - set_link_state(dum_hcd); > + /* Disallow TEST, INDICATOR, and C_OVER_CURRENT */ > + goto error; > } > break; > case GetPortErrorCount:
