During session teardown sequences in vdec_stop_streaming() and vdec_close(), the 'esparser' hardware interrupt handler can still be actively triggered or executing on another CPU core. This creates a transient race condition where the ISR attempts to handle stream data and allocate internal tracking state structures after session contexts have been modified or freed.
Update esparser_isr() to read the current session context utilizing an smp_load_acquire() barrier snapshot. If the pointer resolves to NULL, terminate processing early with IRQ_HANDLED to protect against concurrent dismantling. Suggested-by: Doruk Tan Ozturk <[email protected]> Reported-by: Sashiko <[email protected]> Closes: https://lore.kernel.org/all/[email protected]/ Signed-off-by: Anand Moon <[email protected]> --- drivers/staging/media/meson/vdec/esparser.c | 8 ++++++++ drivers/staging/media/meson/vdec/vdec.c | 4 ++++ drivers/staging/media/meson/vdec/vdec.h | 2 ++ 3 files changed, 14 insertions(+) diff --git a/drivers/staging/media/meson/vdec/esparser.c b/drivers/staging/media/meson/vdec/esparser.c index 4632346f04a9e..37749ede308c6 100644 --- a/drivers/staging/media/meson/vdec/esparser.c +++ b/drivers/staging/media/meson/vdec/esparser.c @@ -60,6 +60,12 @@ static irqreturn_t esparser_isr(int irq, void *dev) { int int_status; struct amvdec_core *core = dev; + struct amvdec_session *sess; + + /* Secure an atomic snapshot to protect against concurrent teardown */ + sess = smp_load_acquire(&core->cur_sess); + if (!sess) + return IRQ_HANDLED; int_status = amvdec_read_parser(core, PARSER_INT_STATUS); amvdec_write_parser(core, PARSER_INT_STATUS, int_status); @@ -439,6 +445,8 @@ int esparser_init(struct platform_device *pdev, struct amvdec_core *core) if (irq < 0) return irq; + core->esparser_irq = irq; + ret = devm_request_irq(dev, irq, esparser_isr, IRQF_SHARED, "esparserirq", core); if (ret) { diff --git a/drivers/staging/media/meson/vdec/vdec.c b/drivers/staging/media/meson/vdec/vdec.c index 7ae3d5a9dd6ab..7689ffdb2e500 100644 --- a/drivers/staging/media/meson/vdec/vdec.c +++ b/drivers/staging/media/meson/vdec/vdec.c @@ -486,6 +486,8 @@ static void vdec_stop_streaming(struct vb2_queue *q) /* Synchronize and flush pending hardware interrupt service routines */ synchronize_irq(core->vdec_irq); + /* Ensure esparser ISR finishes executing */ + synchronize_irq(core->esparser_irq); vdec_poweroff(sess); vdec_free_canvas(sess); @@ -994,6 +996,8 @@ static int vdec_close(struct file *file) /* Synchronize and flush pending hardware interrupt service routines */ synchronize_irq(core->vdec_irq); + /* Ensure esparser ISR finishes executing */ + synchronize_irq(core->esparser_irq); if (!IS_ERR_OR_NULL(sess->recycle_thread)) { kthread_stop(sess->recycle_thread); diff --git a/drivers/staging/media/meson/vdec/vdec.h b/drivers/staging/media/meson/vdec/vdec.h index d165c343fd022..c4639cf33e73e 100644 --- a/drivers/staging/media/meson/vdec/vdec.h +++ b/drivers/staging/media/meson/vdec/vdec.h @@ -68,6 +68,7 @@ struct amvdec_session; * @cur_sess: current decoding session * @lock: video device lock * @vdec_irq: irq for video decoding + * @esparser_irq: irq for elementary stream parsing */ struct amvdec_core { void __iomem *dos_base; @@ -95,6 +96,7 @@ struct amvdec_core { struct amvdec_session *cur_sess; struct mutex lock; int vdec_irq; + int esparser_irq; }; /** -- 2.50.1
