CVE-2025-21824: Vulnerability in Linux Linux

Severity: mediumType: vulnerabilityCVE-2025-21824

In the Linux kernel, the following vulnerability has been resolved: gpu: host1x: Fix a use of uninitialized mutex commit c8347f915e67 ("gpu: host1x: Fix boot regression for Tegra") caused a use of uninitialized mutex leading to below warning when CONFIG_DEBUG_MUTEXES and CONFIG_DEBUG_LOCK_ALLOC are enabled. [ 41.662843] ------------[ cut here ]------------ [ 41.663012] DEBUG_LOCKS_WARN_ON(lock->magic != lock) [ 41.663035] WARNING: CPU: 4 PID: 794 at kernel/locking/mutex.c:587 __mutex_lock+0x670/0x878 [ 41.663458] Modules linked in: rtw88_8822c(+) bluetooth(+) rtw88_pci rtw88_core mac80211 aquantia libarc4 crc_itu_t cfg80211 tegra194_cpufreq dwmac_tegra(+) arm_dsu_pmu stmmac_platform stmmac pcs_xpcs rfkill at24 host1x(+) tegra_bpmp_thermal ramoops reed_solomon fuse loop nfnetlink xfs mmc_block rpmb_core ucsi_ccg ina3221 crct10dif_ce xhci_tegra ghash_ce lm90 sha2_ce sha256_arm64 sha1_ce sdhci_tegra pwm_fan sdhci_pltfm sdhci gpio_keys rtc_tegra cqhci mmc_core phy_tegra_xusb i2c_tegra tegra186_gpc_dma i2c_tegra_bpmp spi_tegra114 dm_mirror dm_region_hash dm_log dm_mod [ 41.665078] CPU: 4 UID: 0 PID: 794 Comm: (udev-worker) Not tainted 6.11.0-29.31_1538613708.el10.aarch64+debug #1 [ 41.665838] Hardware name: NVIDIA NVIDIA Jetson AGX Orin Developer Kit/Jetson, BIOS 36.3.0-gcid-35594366 02/26/2024 [ 41.672555] pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 41.679636] pc : __mutex_lock+0x670/0x878 [ 41.683834] lr : __mutex_lock+0x670/0x878 [ 41.688035] sp : ffff800084b77090 [ 41.691446] x29: ffff800084b77160 x28: ffffdd4bebf7b000 x27: ffffdd4be96b1000 [ 41.698799] x26: 1fffe0002308361c x25: 1ffff0001096ee18 x24: 0000000000000000 [ 41.706149] x23: 0000000000000000 x22: 0000000000000002 x21: ffffdd4be6e3c7a0 [ 41.713500] x20: ffff800084b770f0 x19: ffff00011841b1e8 x18: 0000000000000000 [ 41.720675] x17: 0000000000000000 x16: 0000000000000000 x15: 0720072007200720 [ 41.728023] x14: 0000000000000000 x13: 0000000000000001 x12: ffff6001a96eaab3 [ 41.735375] x11: 1fffe001a96eaab2 x10: ffff6001a96eaab2 x9 : ffffdd4be4838bbc [ 41.742723] x8 : 00009ffe5691554e x7 : ffff000d4b755593 x6 : 0000000000000001 [ 41.749985] x5 : ffff000d4b755590 x4 : 1fffe0001d88f001 x3 : dfff800000000000 [ 41.756988] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff0000ec478000 [ 41.764251] Call trace: [ 41.766695] __mutex_lock+0x670/0x878 [ 41.770373] mutex_lock_nested+0x2c/0x40 [ 41.774134] host1x_intr_start+0x54/0xf8 [host1x] [ 41.778863] host1x_runtime_resume+0x150/0x228 [host1x] [ 41.783935] pm_generic_runtime_resume+0x84/0xc8 [ 41.788485] __rpm_callback+0xa0/0x478 [ 41.792422] rpm_callback+0x15c/0x1a8 [ 41.795922] rpm_resume+0x698/0xc08 [ 41.799597] __pm_runtime_resume+0xa8/0x140 [ 41.803621] host1x_probe+0x810/0xbc0 [host1x] [ 41.807909] platform_probe+0xcc/0x1a8 [ 41.811845] really_probe+0x188/0x800 [ 41.815347] __driver_probe_device+0x164/0x360 [ 41.819810] driver_probe_device+0x64/0x1a8 [ 41.823834] __driver_attach+0x180/0x490 [ 41.827773] bus_for_each_dev+0x104/0x1a0 [ 41.831797] driver_attach+0x44/0x68 [ 41.835296] bus_add_driver+0x23c/0x4e8 [ 41.839235] driver_register+0x15c/0x3a8 [ 41.843170] __platform_register_drivers+0xa4/0x208 [ 41.848159] tegra_host1x_init+0x4c/0xff8 [host1x] [ 41.853147] do_one_initcall+0xd4/0x380 [ 41.856997] do_init_module+0x1dc/0x698 [ 41.860758] load_module+0xc70/0x1300 [ 41.864435] __do_sys_init_module+0x1a8/0x1d0 [ 41.868721] __arm64_sys_init_module+0x74/0xb0 [ 41.873183] invoke_syscall.constprop.0+0xdc/0x1e8 [ 41.877997] do_el0_svc+0x154/0x1d0 [ 41.881671] el0_svc+0x54/0x140 [ 41.884820] el0t_64_sync_handler+0x120/0x130 [ 41.889285] el0t_64_sync+0x1a4/0x1a8 [ 41.892960] irq event stamp: 69737 [ 41.896370] hardirqs last enabled at (69737): [<ffffdd4be6d7768c>] _raw_spin_unlock_irqrestore+0x44/0xe8 [ 41.905739] hardirqs last disabled at (69736): ---truncated---

AI Analysis

Technical Summary

CVE-2025-21824 is a vulnerability identified in the Linux kernel, specifically related to the GPU host1x driver used in NVIDIA Tegra platforms. The issue stems from a use of an uninitialized mutex introduced by commit c8347f915e67, which was intended to fix a boot regression for Tegra devices. When kernel configurations CONFIG_DEBUG_MUTEXES and CONFIG_DEBUG_LOCK_ALLOC are enabled, this flaw triggers a warning indicating a mutex lock operation on an uninitialized mutex. The kernel log excerpts show a DEBUG_LOCKS_WARN_ON failure during __mutex_lock execution, leading to potential instability or undefined behavior in the kernel's locking mechanism. The host1x driver is responsible for managing the NVIDIA Tegra GPU's host interface, and improper mutex handling could cause race conditions or deadlocks during device initialization or runtime resume operations. The vulnerability is specific to Linux kernel versions containing the faulty commit and affects systems running on NVIDIA Jetson AGX Orin Developer Kit hardware or similar Tegra-based platforms. Although no known exploits are reported in the wild, the flaw could lead to kernel warnings, system instability, or crashes under certain debug configurations. The vulnerability does not appear to directly allow privilege escalation or code execution but could degrade system reliability and complicate debugging or development activities on affected devices. No CVSS score has been assigned, and no patches or exploit code are currently linked to this CVE.

Potential Impact

For European organizations utilizing NVIDIA Tegra-based embedded systems, such as Jetson AGX Orin developer kits or similar hardware running affected Linux kernel versions, this vulnerability could cause kernel instability or crashes during GPU driver initialization or runtime resume. This may impact industries relying on edge computing, AI inference, robotics, or IoT devices that use Tegra platforms for GPU acceleration. While the vulnerability does not directly compromise confidentiality or integrity, availability could be affected due to system hangs or reboots triggered by mutex misuse. Organizations deploying these devices in critical infrastructure, manufacturing automation, or research environments may experience operational disruptions. The impact is more pronounced in development or debug environments where CONFIG_DEBUG_MUTEXES and CONFIG_DEBUG_LOCK_ALLOC are enabled, as the issue manifests primarily under these conditions. Since no known exploits exist, the immediate risk is low, but the potential for denial-of-service-like conditions warrants attention in production deployments. Additionally, the complexity of debugging kernel mutex issues could increase maintenance overhead for affected systems.

Mitigation Recommendations

To mitigate CVE-2025-21824, European organizations should: 1) Update the Linux kernel on affected Tegra devices to versions that include the fix for the uninitialized mutex, ensuring the commit c8347f915e67 is replaced or corrected. 2) Avoid running production systems with CONFIG_DEBUG_MUTEXES and CONFIG_DEBUG_LOCK_ALLOC enabled, as these debug options expose the vulnerability and are typically unnecessary outside development environments. 3) Implement rigorous testing of kernel updates in staging environments before deployment to detect any residual stability issues related to host1x driver behavior. 4) Monitor kernel logs for mutex-related warnings or errors indicative of this vulnerability, enabling early detection of potential problems. 5) Coordinate with hardware and OS vendors for timely patches and advisories specific to Tegra platforms. 6) For critical deployments, consider fallback or redundancy mechanisms to maintain availability in case of GPU driver failures. 7) Maintain strict control over kernel module loading and runtime resume processes to minimize exposure during system state transitions.