[syzbot] UBSAN: shift-out-of-bounds in vhci_hub_control (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 84196390 Merge tag 'selinux-pr-20210322' of git://git.kern..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12ea778ad00000
kernel config: https://syzkaller.appspot.com/x/.config?x=5adab0bdee099d7a
dashboard link: https://syzkaller.appspot.com/bug?extid=3dea30b047f41084de66
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15449662d00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14f81026d00000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3dea30...@syzkaller.appspotmail.com

================================================================================
UBSAN: shift-out-of-bounds in drivers/usb/usbip/vhci_hcd.c:605:42
shift exponent 768 is too large for 32-bit type 'int'
CPU: 0 PID: 8421 Comm: syz-executor852 Not tainted 5.12.0-rc4-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+0x141/0x1d7 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:327
vhci_hub_control.cold+0x20b/0x5f0 drivers/usb/usbip/vhci_hcd.c:605
rh_call_control drivers/usb/core/hcd.c:683 [inline]
rh_urb_enqueue drivers/usb/core/hcd.c:841 [inline]
usb_hcd_submit_urb+0xcaf/0x22d0 drivers/usb/core/hcd.c:1544
usb_submit_urb+0x6e4/0x1540 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+0x4af/0x980 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+0x10e2/0x36c0 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+0x44/0xae
RIP: 0033:0x443499
Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 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 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd96535f58 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004004a0 RCX: 0000000000443499
RDX: 0000000020000000 RSI: 00000000c0185500 RDI: 0000000000000003
RBP: 0000000000403040 R08: 0000000000000000 R09: 00000000004004a0
R10: 000000000000000f R11: 0000000000000246 R12: 00000000004030d0
R13: 0000000000000000 R14: 00000000004b1018 R15: 00000000004004a0
================================================================================


---
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syzbot can test patches for this issue, for details see:
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[Muhammad Usama Anjum]

I've tested with following patch locally and issue is solved.
Porting fix from: c318840fb2 ("USB: Gadget: dummy-hcd: Fix shift-out-of-bounds bug")

Lets ask the syzbot to test the patch also.

#syz test: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 84196390

diff --git a/drivers/usb/usbip/vhci_hcd.c b/drivers/usb/usbip/vhci_hcd.c
index 3209b5ddd30c..6e12b60d4f5c 100644
--- a/drivers/usb/usbip/vhci_hcd.c
+++ b/drivers/usb/usbip/vhci_hcd.c
@@ -393,13 +393,24 @@ static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
else
vhci_hcd->port_status[rhport] &= ~USB_PORT_STAT_POWER;
break;
- default:
- usbip_dbg_vhci_rh(" ClearPortFeature: default %x\n",
- wValue);
+ 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:
if (wValue >= 32)
goto error;
vhci_hcd->port_status[rhport] &= ~(1 << wValue);
break;
+ default:
+ /* Disallow INDICATOR and C_OVER_CURRENT */
+ usbip_dbg_vhci_rh(" ClearPortFeature: default %x\n",
+ wValue);
+ goto error;
}
break;
case GetHubDescriptor:
@@ -587,23 +598,22 @@ static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
/* 50msec reset signaling */
vhci_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:
+ /* Disallow TEST, INDICATOR, and C_OVER_CURRENT */
usbip_dbg_vhci_rh(" SetPortFeature: default %d\n",
wValue);
- if (invalid_rhport) {
+ if (invalid_rhport)
pr_err("invalid port number %d\n", wIndex);
- goto error;
- }
- if (hcd->speed == HCD_USB3) {
- if ((vhci_hcd->port_status[rhport] &
- USB_SS_PORT_STAT_POWER) != 0) {
- vhci_hcd->port_status[rhport] |= (1 << wValue);
- }
- } else
- if ((vhci_hcd->port_status[rhport] &
- USB_PORT_STAT_POWER) != 0) {
- vhci_hcd->port_status[rhport] |= (1 << wValue);
- }
+
+ goto error;
}
break;
case GetPortErrorCount:
--
2.25.1

[Shuah Khan]

This won't work for vhci_hcd. You don't want to get rid of this
USB_SS_PORT_STAT_POWER and USB_PORT_STAT_POWER handling for sure.

The other changes to check for invalid values for USB3 and USB2 are
valid, but I would like to see them in a separate patch.

This bug can be fixed with a two line change to check which is done
for ClearPortFeature in commit 718bf42b119de652ebcc93655a1f33a9c0d04b3c

I hav a patch ready to go to fix this:

diff --git a/drivers/usb/usbip/vhci_hcd.c b/drivers/usb/usbip/vhci_hcd.c
index 3209b5ddd30c..a20a8380ca0c 100644
--- a/drivers/usb/usbip/vhci_hcd.c
+++ b/drivers/usb/usbip/vhci_hcd.c
@@ -594,6 +594,8 @@ static int vhci_hub_control(struct usb_hcd *hcd, u16
typeReq, u16 wValue,

pr_err("invalid port number %d\n", wIndex);

goto error;
}
+ if (wValue >= 32)
+ goto error;
if (hcd->speed == HCD_USB3) {

if ((vhci_hcd->port_status[rhport] &

USB_SS_PORT_STAT_POWER) != 0) {
--
2.27.0


thanks,
-- Shuah

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+3dea30...@syzkaller.appspotmail.com

Tested on:

commit: 84196390 Merge tag 'selinux-pr-20210322' of git://git.kern..

git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel config: https://syzkaller.appspot.com/x/.config?x=4b6433fa3370faed
dashboard link: https://syzkaller.appspot.com/bug?extid=3dea30b047f41084de66
compiler:
patch: https://syzkaller.appspot.com/x/patch.diff?x=1702d621d00000

Note: testing is done by a robot and is best-effort only.