When destroy 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
Guard inst destruction (both dec and enc) with hard and threaded
IRQ synchronization.
Signed-off-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
---
drivers/media/platform/qcom/venus/vdec.c | 13 +++++++++++++
drivers/media/platform/qcom/venus/venc.c | 13 +++++++++++++
2 files changed, 26 insertions(+)
diff --git a/drivers/media/platform/qcom/venus/vdec.c b/drivers/media/platform/qcom/venus/vdec.c
index 0013c4704f03..ff1823bc967c 100644
--- a/drivers/media/platform/qcom/venus/vdec.c
+++ b/drivers/media/platform/qcom/venus/vdec.c
@@ -1747,6 +1747,13 @@ static int vdec_close(struct file *file)
{
struct venus_inst *inst = to_inst(file);
+ /*
+ * Make sure we don't have pending IRQs and no threaded IRQ handler is
+ * running nor pending (synchronize_irq)), which can race with inst
+ * destruction.
+ */
+ disable_irq(inst->core->irq);
+
vdec_pm_get(inst);
cancel_work_sync(&inst->delayed_process_work);
@@ -1763,6 +1770,12 @@ static int vdec_close(struct file *file)
vdec_pm_put(inst, false);
+ /*
+ * inst is gone from the core->instances list, re-enable IRQ and
+ * threaded IRQ
+ */
+ enable_irq(inst->core->irq);
+
kfree(inst);
return 0;
}
diff --git a/drivers/media/platform/qcom/venus/venc.c b/drivers/media/platform/qcom/venus/venc.c
index 6a26a6592424..6575e84312fe 100644
--- a/drivers/media/platform/qcom/venus/venc.c
+++ b/drivers/media/platform/qcom/venus/venc.c
@@ -1515,6 +1515,13 @@ static int venc_close(struct file *file)
{
struct venus_inst *inst = to_inst(file);
+ /*
+ * Make sure we don't have pending IRQs and no threaded IRQ handler is
+ * running nor pending (synchronize_irq)), which can race with inst
+ * destruction.
+ */
+ disable_irq(inst->core->irq);
+
venc_pm_get(inst);
v4l2_m2m_ctx_release(inst->m2m_ctx);
@@ -1530,6 +1537,12 @@ static int venc_close(struct file *file)
venc_pm_put(inst, false);
+ /*
+ * inst is gone from the core->instances list, re-enable IRQ and
+ * threaded IRQ
+ */
+ enable_irq(inst->core->irq);
+
kfree(inst);
return 0;
}
--
2.47.0.105.g07ac214952-goog
