| From c6b91d481b927bc979b0dd75f23b74fbceaa838d Mon Sep 17 00:00:00 2001 |
| From: Dmitry Osipenko <digetx@gmail.com> |
| Date: Sun, 9 Feb 2020 19:33:38 +0300 |
| Subject: [PATCH] dmaengine: tegra-apb: Fix use-after-free |
| |
| commit 94788af4ed039476ff3527b0e6a12c1dc42cb022 upstream. |
| |
| I was doing some experiments with I2C and noticed that Tegra APB DMA |
| driver crashes sometime after I2C DMA transfer termination. The crash |
| happens because tegra_dma_terminate_all() bails out immediately if pending |
| list is empty, and thus, it doesn't release the half-completed descriptors |
| which are getting re-used before ISR tasklet kicks-in. |
| |
| tegra-i2c 7000c400.i2c: DMA transfer timeout |
| elants_i2c 0-0010: elants_i2c_irq: failed to read data: -110 |
| ------------[ cut here ]------------ |
| WARNING: CPU: 0 PID: 142 at lib/list_debug.c:45 __list_del_entry_valid+0x45/0xac |
| list_del corruption, ddbaac44->next is LIST_POISON1 (00000100) |
| Modules linked in: |
| CPU: 0 PID: 142 Comm: kworker/0:2 Not tainted 5.5.0-rc2-next-20191220-00175-gc3605715758d-dirty #538 |
| Hardware name: NVIDIA Tegra SoC (Flattened Device Tree) |
| Workqueue: events_freezable_power_ thermal_zone_device_check |
| [<c010e5c5>] (unwind_backtrace) from [<c010a1c5>] (show_stack+0x11/0x14) |
| [<c010a1c5>] (show_stack) from [<c0973925>] (dump_stack+0x85/0x94) |
| [<c0973925>] (dump_stack) from [<c011f529>] (__warn+0xc1/0xc4) |
| [<c011f529>] (__warn) from [<c011f7e9>] (warn_slowpath_fmt+0x61/0x78) |
| [<c011f7e9>] (warn_slowpath_fmt) from [<c042497d>] (__list_del_entry_valid+0x45/0xac) |
| [<c042497d>] (__list_del_entry_valid) from [<c047a87f>] (tegra_dma_tasklet+0x5b/0x154) |
| [<c047a87f>] (tegra_dma_tasklet) from [<c0124799>] (tasklet_action_common.constprop.0+0x41/0x7c) |
| [<c0124799>] (tasklet_action_common.constprop.0) from [<c01022ab>] (__do_softirq+0xd3/0x2a8) |
| [<c01022ab>] (__do_softirq) from [<c0124683>] (irq_exit+0x7b/0x98) |
| [<c0124683>] (irq_exit) from [<c0168c19>] (__handle_domain_irq+0x45/0x80) |
| [<c0168c19>] (__handle_domain_irq) from [<c043e429>] (gic_handle_irq+0x45/0x7c) |
| [<c043e429>] (gic_handle_irq) from [<c0101aa5>] (__irq_svc+0x65/0x94) |
| Exception stack(0xde2ebb90 to 0xde2ebbd8) |
| |
| Signed-off-by: Dmitry Osipenko <digetx@gmail.com> |
| Acked-by: Jon Hunter <jonathanh@nvidia.com> |
| Cc: <stable@vger.kernel.org> |
| Link: https://lore.kernel.org/r/20200209163356.6439-2-digetx@gmail.com |
| Signed-off-by: Vinod Koul <vkoul@kernel.org> |
| Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c |
| index 79e9593815f1..860bbb71e629 100644 |
| --- a/drivers/dma/tegra20-apb-dma.c |
| +++ b/drivers/dma/tegra20-apb-dma.c |
| @@ -751,10 +751,6 @@ static int tegra_dma_terminate_all(struct dma_chan *dc) |
| bool was_busy; |
| |
| spin_lock_irqsave(&tdc->lock, flags); |
| - if (list_empty(&tdc->pending_sg_req)) { |
| - spin_unlock_irqrestore(&tdc->lock, flags); |
| - return 0; |
| - } |
| |
| if (!tdc->busy) |
| goto skip_dma_stop; |
| -- |
| 2.7.4 |
| |
