From: Nikita Zhandarovich n.zhandarovich@fintech.ru

stable inclusion from stable-v6.6.35 commit 30f76bc468b9b2cbbd5d3eb482661e3e4798893f category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAD00R CVE: CVE-2024-39509

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...

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[ Upstream commit 4aa2dcfbad538adf7becd0034a3754e1bd01b2b5 ]

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 Suggested-by: Alan Stern stern@rowland.harvard.edu Signed-off-by: Nikita Zhandarovich n.zhandarovich@fintech.ru Signed-off-by: Jiri Kosina jkosina@suse.com Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Wang Hai wanghai38@huawei.com --- drivers/hid/hid-core.c | 1 - 1 file changed, 1 deletion(-)

diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c index e0181218ad85..85ddeb13a3fa 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; } }