CVE-2024-39509
MediumCVSS 5.5Exploitation Probability (EPSS)
Low risk21th percentile - higher than 21% of all known CVEs
Summary
In the Linux kernel, a vulnerability was resolved in the HID subsystem where the implement() function triggered a WARN_ON() when writing a value into a smaller-sized field in an output report. The warning was unnecessary because the value is already trimmed and hid_warn() prints a warning message. The WARN_ON() was removed to suppress future syzkaller triggers.
Risk Assessment
The vulnerability can lead to a kernel warning (WARN_ON) and log spam, which in some configurations could be exploited for a denial of service (DoS) attack by triggering a kernel panic if panic_on_warn is enabled. In production environments, this may cause unnecessary reboots or system instability.
Recommendation
Update the Linux kernel to a version containing the fix (commit removing WARN_ON in implement()). If updating is not possible, consider disabling panic_on_warn or restricting access to HID interfaces for unprivileged users.
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Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: HID: core: remove unnecessary WARN_ON() in implement() 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 ...
Vulnerability data from NVD (NIST) · CISA KEV · EPSS

