| Message ID | 20240517141914.8604-1-n.zhandarovich@fintech.ru (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | 4aa2dcfbad538adf7becd0034a3754e1bd01b2b5 |
| Delegated to: | Jiri Kosina |
| Headers | show |
| Series | HID: core: remove unnecessary WARN_ON() in implement() | expand |
On Fri, 17 May 2024, Nikita Zhandarovich wrote: > Syzkaller hit a warning [1] in a call to implement() when trying > to write a value into a field of smaller size in an output report. > > Since implement() already has a warn message printed out with the > help of hid_warn() and value in question gets trimmed with: > ... > value &= m; > ... > WARN_ON may be considered superfluous. Remove it to suppress future > syzkaller triggers. > > [1] > WARNING: CPU: 0 PID: 5084 at drivers/hid/hid-core.c:1451 implement drivers/hid/hid-core.c:1451 [inline] > WARNING: CPU: 0 PID: 5084 at drivers/hid/hid-core.c:1451 hid_output_report+0x548/0x760 drivers/hid/hid-core.c:1863 > Modules linked in: > CPU: 0 PID: 5084 Comm: syz-executor424 Not tainted 6.9.0-rc7-syzkaller-00183-gcf87f46fd34d #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 > RIP: 0010:implement drivers/hid/hid-core.c:1451 [inline] > RIP: 0010:hid_output_report+0x548/0x760 drivers/hid/hid-core.c:1863 > ... > Call Trace: > <TASK> > __usbhid_submit_report drivers/hid/usbhid/hid-core.c:591 [inline] > usbhid_submit_report+0x43d/0x9e0 drivers/hid/usbhid/hid-core.c:636 > hiddev_ioctl+0x138b/0x1f00 drivers/hid/usbhid/hiddev.c:726 > vfs_ioctl fs/ioctl.c:51 [inline] > __do_sys_ioctl fs/ioctl.c:904 [inline] > __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:890 > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > ... > > Fixes: 95d1c8951e5b ("HID: simplify implement() a bit") > Reported-by: syzbot+5186630949e3c55f0799@syzkaller.appspotmail.com > Signed-off-by: Nikita Zhandarovich <n.zhandarovich@fintech.ru> I've added Suggested-by: Alan Stern <stern@rowland.harvard.edu> and applied. Thanks,
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c index b1fa0378e8f4..74efda212c55 100644 --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -1448,7 +1448,6 @@ static void implement(const struct hid_device *hid, u8 *report, hid_warn(hid, "%s() called with too large value %d (n: %d)! (%s)\n", __func__, value, n, current->comm); - WARN_ON(1); value &= m; } }
Syzkaller hit a warning [1] in a call to implement() when trying to write a value into a field of smaller size in an output report. Since implement() already has a warn message printed out with the help of hid_warn() and value in question gets trimmed with: ... value &= m; ... WARN_ON may be considered superfluous. Remove it to suppress future syzkaller triggers. [1] WARNING: CPU: 0 PID: 5084 at drivers/hid/hid-core.c:1451 implement drivers/hid/hid-core.c:1451 [inline] WARNING: CPU: 0 PID: 5084 at drivers/hid/hid-core.c:1451 hid_output_report+0x548/0x760 drivers/hid/hid-core.c:1863 Modules linked in: CPU: 0 PID: 5084 Comm: syz-executor424 Not tainted 6.9.0-rc7-syzkaller-00183-gcf87f46fd34d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 RIP: 0010:implement drivers/hid/hid-core.c:1451 [inline] RIP: 0010:hid_output_report+0x548/0x760 drivers/hid/hid-core.c:1863 ... Call Trace: <TASK> __usbhid_submit_report drivers/hid/usbhid/hid-core.c:591 [inline] usbhid_submit_report+0x43d/0x9e0 drivers/hid/usbhid/hid-core.c:636 hiddev_ioctl+0x138b/0x1f00 drivers/hid/usbhid/hiddev.c:726 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:904 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:890 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f ... Fixes: 95d1c8951e5b ("HID: simplify implement() a bit") Reported-by: syzbot+5186630949e3c55f0799@syzkaller.appspotmail.com Signed-off-by: Nikita Zhandarovich <n.zhandarovich@fintech.ru> --- drivers/hid/hid-core.c | 1 - 1 file changed, 1 deletion(-)