CVE-2025-39995

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> media: i2c: tc358743: Fix use-after-free bugs caused by orphan timer in probe<br /> <br /> The state-&gt;timer is a cyclic timer that schedules work_i2c_poll and<br /> delayed_work_enable_hotplug, while rearming itself. Using timer_delete()<br /> fails to guarantee the timer isn&amp;#39;t still running when destroyed, similarly<br /> cancel_delayed_work() cannot ensure delayed_work_enable_hotplug has<br /> terminated if already executing. During probe failure after timer<br /> initialization, these may continue running as orphans and reference the<br /> already-freed tc358743_state object through tc358743_irq_poll_timer.<br /> <br /> The following is the trace captured by KASAN.<br /> <br /> BUG: KASAN: slab-use-after-free in __run_timer_base.part.0+0x7d7/0x8c0<br /> Write of size 8 at addr ffff88800ded83c8 by task swapper/1/0<br /> ...<br /> Call Trace:<br /> <br /> dump_stack_lvl+0x55/0x70<br /> print_report+0xcf/0x610<br /> ? __pfx_sched_balance_find_src_group+0x10/0x10<br /> ? __run_timer_base.part.0+0x7d7/0x8c0<br /> kasan_report+0xb8/0xf0<br /> ? __run_timer_base.part.0+0x7d7/0x8c0<br /> __run_timer_base.part.0+0x7d7/0x8c0<br /> ? rcu_sched_clock_irq+0xb06/0x27d0<br /> ? __pfx___run_timer_base.part.0+0x10/0x10<br /> ? try_to_wake_up+0xb15/0x1960<br /> ? tmigr_update_events+0x280/0x740<br /> ? _raw_spin_lock_irq+0x80/0xe0<br /> ? __pfx__raw_spin_lock_irq+0x10/0x10<br /> tmigr_handle_remote_up+0x603/0x7e0<br /> ? __pfx_tmigr_handle_remote_up+0x10/0x10<br /> ? sched_balance_trigger+0x98/0x9f0<br /> ? sched_tick+0x221/0x5a0<br /> ? _raw_spin_lock_irq+0x80/0xe0<br /> ? __pfx__raw_spin_lock_irq+0x10/0x10<br /> ? tick_nohz_handler+0x339/0x440<br /> ? __pfx_tmigr_handle_remote_up+0x10/0x10<br /> __walk_groups.isra.0+0x42/0x150<br /> tmigr_handle_remote+0x1f4/0x2e0<br /> ? __pfx_tmigr_handle_remote+0x10/0x10<br /> ? ktime_get+0x60/0x140<br /> ? lapic_next_event+0x11/0x20<br /> ? clockevents_program_event+0x1d4/0x2a0<br /> ? hrtimer_interrupt+0x322/0x780<br /> handle_softirqs+0x16a/0x550<br /> irq_exit_rcu+0xaf/0xe0<br /> sysvec_apic_timer_interrupt+0x70/0x80<br /> <br /> ...<br /> <br /> Allocated by task 141:<br /> kasan_save_stack+0x24/0x50<br /> kasan_save_track+0x14/0x30<br /> __kasan_kmalloc+0x7f/0x90<br /> __kmalloc_node_track_caller_noprof+0x198/0x430<br /> devm_kmalloc+0x7b/0x1e0<br /> tc358743_probe+0xb7/0x610 i2c_device_probe+0x51d/0x880<br /> really_probe+0x1ca/0x5c0<br /> __driver_probe_device+0x248/0x310<br /> driver_probe_device+0x44/0x120<br /> __device_attach_driver+0x174/0x220<br /> bus_for_each_drv+0x100/0x190<br /> __device_attach+0x206/0x370<br /> bus_probe_device+0x123/0x170<br /> device_add+0xd25/0x1470<br /> i2c_new_client_device+0x7a0/0xcd0<br /> do_one_initcall+0x89/0x300<br /> do_init_module+0x29d/0x7f0<br /> load_module+0x4f48/0x69e0<br /> init_module_from_file+0xe4/0x150<br /> idempotent_init_module+0x320/0x670<br /> __x64_sys_finit_module+0xbd/0x120<br /> do_syscall_64+0xac/0x280<br /> entry_SYSCALL_64_after_hwframe+0x77/0x7f<br /> <br /> Freed by task 141:<br /> kasan_save_stack+0x24/0x50<br /> kasan_save_track+0x14/0x30<br /> kasan_save_free_info+0x3a/0x60<br /> __kasan_slab_free+0x3f/0x50<br /> kfree+0x137/0x370<br /> release_nodes+0xa4/0x100<br /> devres_release_group+0x1b2/0x380<br /> i2c_device_probe+0x694/0x880<br /> really_probe+0x1ca/0x5c0<br /> __driver_probe_device+0x248/0x310<br /> driver_probe_device+0x44/0x120<br /> __device_attach_driver+0x174/0x220<br /> bus_for_each_drv+0x100/0x190<br /> __device_attach+0x206/0x370<br /> bus_probe_device+0x123/0x170<br /> device_add+0xd25/0x1470<br /> i2c_new_client_device+0x7a0/0xcd0<br /> do_one_initcall+0x89/0x300<br /> do_init_module+0x29d/0x7f0<br /> load_module+0x4f48/0x69e0<br /> init_module_from_file+0xe4/0x150<br /> idempotent_init_module+0x320/0x670<br /> __x64_sys_finit_module+0xbd/0x120<br /> do_syscall_64+0xac/0x280<br /> entry_SYSCALL_64_after_hwframe+0x77/0x7f<br /> ...<br /> <br /> Replace timer_delete() with timer_delete_sync() and cancel_delayed_work()<br /> with cancel_delayed_work_sync() to ensure proper termination of timer and<br /> work items before resource cleanup.<br /> <br /> This bug was initially identified through static analysis. For reproduction<br /> and testing, I created a functional emulation of the tc358743 device via a<br /> kernel module and introduced faults through the debugfs interface.