When destroying an inst we should make sure that we don't race against threaded IRQ (or pending IRQ), otherwise we can concurrently kfree() inst context and inst itself. BUG: KASAN: slab-use-after-free in vb2_queue_error+0x80/0x90 Call trace: dump_backtrace+0x1c4/0x1f8 show_stack+0x38/0x60 dump_stack_lvl+0x168/0x1f0 print_report+0x170/0x4c8 kasan_report+0x94/0xd0 __asan_report_load2_noabort+0x20/0x30 vb2_queue_error+0x80/0x90 venus_helper_vb2_queue_error+0x54/0x78 venc_event_notify+0xec/0x158 hfi_event_notify+0x878/0xd20 hfi_process_msg_packet+0x27c/0x4e0 venus_isr_thread+0x258/0x6e8 hfi_isr_thread+0x70/0x90 venus_isr_thread+0x34/0x50 irq_thread_fn+0x88/0x130 irq_thread+0x160/0x2c0 kthread+0x294/0x328 ret_from_fork+0x10/0x20 Allocated by task 20291: kasan_set_track+0x4c/0x80 kasan_save_alloc_info+0x28/0x38 __kasan_kmalloc+0x84/0xa0 kmalloc_trace+0x7c/0x98 v4l2_m2m_ctx_init+0x74/0x280 venc_open+0x444/0x6d0 v4l2_open+0x19c/0x2a0 chrdev_open+0x374/0x3f0 do_dentry_open+0x710/0x10a8 vfs_open+0x88/0xa8 path_openat+0x1e6c/0x2700 do_filp_open+0x1a4/0x2e0 do_sys_openat2+0xe8/0x508 do_sys_open+0x15c/0x1a0 __arm64_sys_openat+0xa8/0xc8 invoke_syscall+0xdc/0x270 el0_svc_common+0x1ec/0x250 do_el0_svc+0x54/0x70 el0_svc+0x50/0xe8 el0t_64_sync_handler+0x48/0x120 el0t_64_sync+0x1a8/0x1b0 Re-arragne inst destruction. First remove the inst from the core ->instacnes list, second synchronize IRQ/IRQ-thread to make sure that nothing else would see the inst while we take it down. Signed-off-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx> --- drivers/media/platform/qcom/venus/vdec.c | 12 +++++++++++- drivers/media/platform/qcom/venus/venc.c | 12 +++++++++++- 2 files changed, 22 insertions(+), 2 deletions(-) diff --git a/drivers/media/platform/qcom/venus/vdec.c b/drivers/media/platform/qcom/venus/vdec.c index 0013c4704f03..b3192a36f388 100644 --- a/drivers/media/platform/qcom/venus/vdec.c +++ b/drivers/media/platform/qcom/venus/vdec.c @@ -1750,10 +1750,20 @@ static int vdec_close(struct file *file) vdec_pm_get(inst); cancel_work_sync(&inst->delayed_process_work); + /* + * First, remove the inst from the ->instances list, so that + * to_instance() will return NULL. + */ + hfi_session_destroy(inst); + /* + * Second, make sure we don't have IRQ/IRQ-thread currently running + * or pending execution, which would race with the inst destruction. + */ + synchronize_irq(inst->core->irq); + v4l2_m2m_ctx_release(inst->m2m_ctx); v4l2_m2m_release(inst->m2m_dev); ida_destroy(&inst->dpb_ids); - hfi_session_destroy(inst); v4l2_fh_del(&inst->fh); v4l2_fh_exit(&inst->fh); vdec_ctrl_deinit(inst); diff --git a/drivers/media/platform/qcom/venus/venc.c b/drivers/media/platform/qcom/venus/venc.c index 6a26a6592424..36981ce448f5 100644 --- a/drivers/media/platform/qcom/venus/venc.c +++ b/drivers/media/platform/qcom/venus/venc.c @@ -1517,9 +1517,19 @@ static int venc_close(struct file *file) venc_pm_get(inst); + /* + * First, remove the inst from the ->instances list, so that + * to_instance() will return NULL. + */ + hfi_session_destroy(inst); + /* + * Second, make sure we don't have IRQ/IRQ-thread currently running + * or pending execution, which would race with the inst destruction. + */ + synchronize_irq(inst->core->irq); + v4l2_m2m_ctx_release(inst->m2m_ctx); v4l2_m2m_release(inst->m2m_dev); - hfi_session_destroy(inst); v4l2_fh_del(&inst->fh); v4l2_fh_exit(&inst->fh); venc_ctrl_deinit(inst); -- 2.47.0.163.g1226f6d8fa-goog
