# CVE-2025-39995: media: i2c: tc358743: Fix use-after-free bugs caused by orphan timer in probe > A use-after-free vulnerability in the Linux kernel tc358743 driver allows local attackers to cause a system crash or potentially execute arbitrary code during device probe failures. - **Severity:** Not scored - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Local or same network only - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 15 Oct 2025 - **Updated:** 11 May 2026 - **Also known as:** BELL-CVE-2025-39995, DEBIAN-CVE-2025-39995, GHSA-fxhq-536w-f9c9, ROOT-OS-DEBIAN-11-CVE-2025-39995, ROOT-OS-DEBIAN-12-CVE-2025-39995, ROOT-OS-DEBIAN-13-CVE-2025-39995, ROOT-OS-UBUNTU-2204-CVE-2025-39995, ROOT-OS-UBUNTU-2404-CVE-2025-39995, UBUNTU-CVE-2025-39995 ## What is CVE-2025-39995? CVE-2025-39995 is an use after free vulnerability in Linux, published on 15 Oct 2025. It can only be exploited from the same machine or local network, with no action from the victim. ### Official description In the Linux kernel, the following vulnerability has been resolved: media: i2c: tc358743: Fix use-after-free bugs caused by orphan timer in probe The state->timer is a cyclic timer that schedules work_i2c_poll and delayed_work_enable_hotplug, while rearming itself. Using timer_delete() fails to guarantee the timer isn't still running when destroyed, similarly cancel_delayed_work() cannot ensure delayed_work_enable_hotplug has terminated if already executing. During probe failure after timer initialization, these may continue running as orphans and reference the already-freed tc358743_state object through tc358743_irq_poll_timer. The following is the trace captured by KASAN. BUG: KASAN: slab-use-after-free in __run_timer_base.part.0+0x7d7/0x8c0 Write of size 8 at addr ffff88800ded83c8 by task swapper/1/0 ... Call Trace: dump_stack_lvl+0x55/0x70 print_report+0xcf/0x610 ? __pfx_sched_balance_find_src_group+0x10/0x10 ? __run_timer_base.part.0+0x7d7/0x8c0 kasan_report+0xb8/0xf0 ? __run_timer_base.part.0+0x7d7/0x8c0 __run_timer_base.part.0+0x7d7/0x8c0 ? rcu_sched_clock_irq+0xb06/0x27d0 ? __pfx___run_timer_base.part.0+0x10/0x10 ? try_to_wake_up+0xb15/0x1960 ? tmigr_update_events+0x280/0x740 ? _raw_spin_lock_irq+0x80/0xe0 ? __pfx__raw_spin_lock_irq+0x10/0x10 tmigr_handle_remote_up+0x603/0x7e0 ? __pfx_tmigr_handle_remote_up+0x10/0x10 ? sched_balance_trigger+0x98/0x9f0 ? sched_tick+0x221/0x5a0 ? _raw_spin_lock_irq+0x80/0xe0 ? __pfx__raw_spin_lock_irq+0x10/0x10 ? tick_nohz_handler+0x339/0x440 ? __pfx_tmigr_handle_remote_up+0x10/0x10 __walk_groups.isra.0+0x42/0x150 tmigr_handle_remote+0x1f4/0x2e0 ? __pfx_tmigr_handle_remote+0x10/0x10 ? ktime_get+0x60/0x140 ? lapic_next_event+0x11/0x20 ? clockevents_program_event+0x1d4/0x2a0 ? hrtimer_interrupt+0x322/0x780 handle_softirqs+0x16a/0x550 irq_exit_rcu+0xaf/0xe0 sysvec_apic_timer_interrupt+0x70/0x80 ... Allocated by task 141: kasan_save_stack+0x24/0x50 kasan_save_track+0x14/0x30 __kasan_kmalloc+0x7f/0x90 __kmalloc_node_track_caller_noprof+0x198/0x430 devm_kmalloc+0x7b/0x1e0 tc358743_probe+0xb7/0x610 i2c_device_probe+0x51d/0x880 really_probe+0x1ca/0x5c0 __driver_probe_device+0x248/0x310 driver_probe_device+0x44/0x120 __device_attach_driver+0x174/0x220 bus_for_each_drv+0x100/0x190 __device_attach+0x206/0x370 bus_probe_device+0x123/0x170 device_add+0xd25/0x1470 i2c_new_client_device+0x7a0/0xcd0 do_one_initcall+0x89/0x300 do_init_module+0x29d/0x7f0 load_module+0x4f48/0x69e0 init_module_from_file+0xe4/0x150 idempotent_init_module+0x320/0x670 __x64_sys_finit_module+0xbd/0x120 do_syscall_64+0xac/0x280 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 141: kasan_save_stack+0x24/0x50 kasan_save_track+0x14/0x30 kasan_save_free_info+0x3a/0x60 __kasan_slab_free+0x3f/0x50 kfree+0x137/0x370 release_nodes+0xa4/0x100 devres_release_group+0x1b2/0x380 i2c_device_probe+0x694/0x880 really_probe+0x1ca/0x5c0 __driver_probe_device+0x248/0x310 driver_probe_device+0x44/0x120 __device_attach_driver+0x174/0x220 bus_for_each_drv+0x100/0x190 __device_attach+0x206/0x370 bus_probe_device+0x123/0x170 device_add+0xd25/0x1470 i2c_new_client_device+0x7a0/0xcd0 do_one_initcall+0x89/0x300 do_init_module+0x29d/0x7f0 load_module+0x4f48/0x69e0 init_module_from_file+0xe4/0x150 idempotent_init_module+0x320/0x670 __x64_sys_finit_module+0xbd/0x120 do_syscall_64+0xac/0x280 entry_SYSCALL_64_after_hwframe+0x77/0x7f ... Replace timer_delete() with timer_delete_sync() and cancel_delayed_work() with cancel_delayed_work_sync() to ensure proper termination of timer and work items before resource cleanup. This bug was initially identified through static analysis. For reproduction and testing, I created a functional emulation of the tc358743 device via a kernel module and introduced faults through the debugfs interface. ## Which versions are affected by CVE-2025-39995? ## How do I fix CVE-2025-39995? Apply the vendor's patch. ## Is CVE-2025-39995 being exploited? There is no known exploitation of CVE-2025-39995 in the wild and no public exploit code. ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2025-39995 and fix it if it is affected. What it is: CVE-2025-39995 is an use after free vulnerability in Linux, published on 15 Oct 2025. It can only be exploited from the same machine or local network, with no action from the victim. Exploitation: There is no known exploitation of CVE-2025-39995 in the wild and no public exploit code. Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page. Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2025-39995/ (Markdown: https://insights.sbomify.com/CVE-2025-39995/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2025-39995 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-39995 - OSV: https://osv.dev/vulnerability/CVE-2025-39995 --- From sbomify Insights: https://insights.sbomify.com/CVE-2025-39995/ Summaries are generated and may contain mistakes; the official description above is the record.