In the Linux kernel, the following vulnerability has been resolved: dmaengine: tegra-adma: Fix use-after-free A use-after-free bug exists in the Tegra ADMA driver when audio streams are terminated, particularly during XRUN conditions. The issue occurs when the DMA buffer is freed by tegra_adma_terminate_all() before the vchan completion tasklet finishes accessing it. The race condition follows this sequence: 1. DMA transfer completes, triggering an interrupt that schedules the completion tasklet (tasklet has not executed yet) 2. Audio playback stops, calling tegra_adma_terminate_all() which frees the DMA buffer memory via kfree() 3. The scheduled tasklet finally executes, calling vchan_complete() which attempts to access the already-freed memory Since tasklets can execute at any time after being scheduled, there is no guarantee that the buffer will remain valid when vchan_complete() runs. Fix this by properly synchronizing the virtual channel completion: - Calling vchan_terminate_vdesc() in tegra_adma_stop() to mark the descriptors as terminated instead of freeing the descriptor. - Add the callback tegra_adma_synchronize() that calls vchan_synchronize() which kills any pending tasklets and frees any terminated descriptors. Crash logs: [ 337.427523] BUG: KASAN: use-after-free in vchan_complete+0x124/0x3b0 [ 337.427544] Read of size 8 at addr ffff000132055428 by task swapper/0/0 [ 337.427562] Call trace: [ 337.427564] dump_backtrace+0x0/0x320 [ 337.427571] show_stack+0x20/0x30 [ 337.427575] dump_stack_lvl+0x68/0x84 [ 337.427584] print_address_description.constprop.0+0x74/0x2b8 [ 337.427590] kasan_report+0x1f4/0x210 [ 337.427598] __asan_load8+0xa0/0xd0 [ 337.427603] vchan_complete+0x124/0x3b0 [ 337.427609] tasklet_action_common.constprop.0+0x190/0x1d0 [ 337.427617] tasklet_action+0x30/0x40 [ 337.427623] __do_softirq+0x1a0/0x5c4 [ 337.427628] irq_exit+0x110/0x140 [ 337.427633] handle_domain_irq+0xa4/0xe0 [ 337.427640] gic_handle_irq+0x64/0x160 [ 337.427644] call_on_irq_stack+0x20/0x4c [ 337.427649] do_interrupt_handler+0x7c/0x90 [ 337.427654] el1_interrupt+0x30/0x80 [ 337.427659] el1h_64_irq_handler+0x18/0x30 [ 337.427663] el1h_64_irq+0x7c/0x80 [ 337.427667] cpuidle_enter_state+0xe4/0x540 [ 337.427674] cpuidle_enter+0x54/0x80 [ 337.427679] do_idle+0x2e0/0x380 [ 337.427685] cpu_startup_entry+0x2c/0x70 [ 337.427690] rest_init+0x114/0x130 [ 337.427695] arch_call_rest_init+0x18/0x24 [ 337.427702] start_kernel+0x380/0x3b4 [ 337.427706] __primary_switched+0xc0/0xc8
En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta: dmaengine: tegra-adma: Corrección de uso después de liberación Existe un error de uso después de liberación en el controlador Tegra ADMA cuando las transmisiones de audio son terminadas, particularmente durante condiciones XRUN. El problema ocurre cuando el búfer DMA es liberado por tegra_adma_terminate_all() antes de que la tarea de finalización de vchan termine de acceder a él. La condición de carrera sigue esta secuencia: 1. La transferencia DMA se completa, desencadenando una interrupción que programa la tarea de finalización (la tarea aún no se ha ejecutado) 2. La reproducción de audio se detiene, llamando a tegra_adma_terminate_all() que libera la memoria del búfer DMA a través de kfree() 3. La tarea programada finalmente se ejecuta, llamando a vchan_complete() que intenta acceder a la memoria ya liberada Dado que las tareas pueden ejecutarse en cualquier momento después de ser programadas, no hay garantía de que el búfer permanezca válido cuando se ejecuta vchan_complete(). Corrija esto mediante la sincronización adecuada de la finalización del canal virtual: - Llamando a vchan_terminate_vdesc() en tegra_adma_stop() para marcar los descriptores como terminados en lugar de liberar el descriptor. - Agregue la función de devolución de llamada tegra_adma_synchronize() que llama a vchan_synchronize() que elimina cualquier tarea pendiente y libera cualquier descriptor terminado. Registros de fallos: [ 337.427523] BUG: KASAN: uso después de liberación en vchan_complete+0x124/0x3b0 [ 337.427544] Lectura de tamaño 8 en la dirección ffff000132055428 por la tarea swapper/0/0 [ 337.427562] Traza de llamada: [ 337.427564] dump_backtrace+0x0/0x320 [ 337.427571] show_stack+0x20/0x30 [ 337.427575] dump_stack_lvl+0x68/0x84 [ 337.427584] print_address_description.constprop.0+0x74/0x2b8 [ 337.427590] kasan_report+0x1f4/0x210 [ 337.427598] __asan_load8+0xa0/0xd0 [ 337.427603] vchan_complete+0x124/0x3b0 [ 337.427609] tasklet_action_common.constprop.0+0x190/0x1d0 [ 337.427617] tasklet_action+0x30/0x40 [ 337.427623] __do_softirq+0x1a0/0x5c4 [ 337.427628] irq_exit+0x110/0x140 [ 337.427633] handle_domain_irq+0xa4/0xe0 [ 337.427640] gic_handle_irq+0x64/0x160 [ 337.427644] call_on_irq_stack+0x20/0x4c [ 337.427649] do_interrupt_handler+0x7c/0x90 [ 337.427654] el1_interrupt+0x30/0x80 [ 337.427659] el1h_64_irq_handler+0x18/0x30 [ 337.427663] el1h_64_irq+0x7c/0x80 [ 337.427667] cpuidle_enter_state+0xe4/0x540 [ 337.427674] cpuidle_enter+0x54/0x80 [ 337.427679] do_idle+0x2e0/0x380 [ 337.427685] cpu_startup_entry+0x2c/0x70 [ 337.427690] rest_init+0x114/0x130 [ 337.427695] arch_call_rest_init+0x18/0x24 [ 337.427702] start_kernel+0x380/0x3b4 [ 337.427706] __primary_switched+0xc0/0xc8
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
| Attack Vector | LOCAL |
|---|---|
| Attack Complexity | LOW |
| Privileges Required | LOW |
| User Interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality Impact | HIGH |
| Integrity Impact | HIGH |
| Availability Impact | HIGH |
| Source | Type | Description |
|---|---|---|
| [email protected] | Primary |
en
CWE-416
|
| Vendor | Product | Version | Update | Type |
|---|---|---|---|---|
| linux | linux_kernel | * | <built-in method update of dict object at 0x702bde36b680> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x702bdd128ac0> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x702bdd12b580> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x702c04620580> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x702bde534040> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x702bde535400> | Operating System |
| linux | linux_kernel | 6.19 | <built-in method update of dict object at 0x702c04621d40> | Operating System |
| linux | linux_kernel | 6.19 | <built-in method update of dict object at 0x702bde537a40> | Operating System |
| linux | linux_kernel | 6.19 | <built-in method update of dict object at 0x702bdc373e40> | Operating System |
| linux | linux_kernel | 6.19 | <built-in method update of dict object at 0x702bde535fc0> | Operating System |
| linux | linux_kernel | 6.19 | <built-in method update of dict object at 0x702b50627380> | Operating System |
| Vulnerable | CPE |
|---|---|
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:6.19:rc1:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:6.19:rc2:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:6.19:rc3:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:6.19:rc4:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:6.19:rc5:*:*:*:*:*:* |