4.4-stable patches

added patches:
	dmaengine-tegra-apb-fix-use-after-free.patch
	dmaengine-tegra-apb-prevent-race-conditions-of-tasklet-vs-free-list.patch

diff --git a/queue-4.4/dmaengine-tegra-apb-fix-use-after-free.patch b/queue-4.4/dmaengine-tegra-apb-fix-use-after-free.patch
new file mode 100644 (file)
index 0000000..db44fe1
--- /dev/null
+++ b/queue-4.4/dmaengine-tegra-apb-fix-use-after-free.patch
@@ -0,0 +1,62 @@
+From 94788af4ed039476ff3527b0e6a12c1dc42cb022 Mon Sep 17 00:00:00 2001
+From: Dmitry Osipenko <digetx@gmail.com>
+Date: Sun, 9 Feb 2020 19:33:38 +0300
+Subject: dmaengine: tegra-apb: Fix use-after-free
+
+From: Dmitry Osipenko <digetx@gmail.com>
+
+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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ drivers/dma/tegra20-apb-dma.c |    4 ----
+ 1 file changed, 4 deletions(-)
+
+--- a/drivers/dma/tegra20-apb-dma.c
++++ b/drivers/dma/tegra20-apb-dma.c
+@@ -754,10 +754,6 @@ static int tegra_dma_terminate_all(struc
+       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;

diff --git a/queue-4.4/dmaengine-tegra-apb-prevent-race-conditions-of-tasklet-vs-free-list.patch b/queue-4.4/dmaengine-tegra-apb-prevent-race-conditions-of-tasklet-vs-free-list.patch
new file mode 100644 (file)
index 0000000..12d24e7
--- /dev/null
+++ b/queue-4.4/dmaengine-tegra-apb-prevent-race-conditions-of-tasklet-vs-free-list.patch
@@ -0,0 +1,37 @@
+From c33ee1301c393a241d6424e36eff1071811b1064 Mon Sep 17 00:00:00 2001
+From: Dmitry Osipenko <digetx@gmail.com>
+Date: Sun, 9 Feb 2020 19:33:39 +0300
+Subject: dmaengine: tegra-apb: Prevent race conditions of tasklet vs free list
+
+From: Dmitry Osipenko <digetx@gmail.com>
+
+commit c33ee1301c393a241d6424e36eff1071811b1064 upstream.
+
+The interrupt handler puts a half-completed DMA descriptor on a free list
+and then schedules tasklet to process bottom half of the descriptor that
+executes client's callback, this creates possibility to pick up the busy
+descriptor from the free list. Thus, let's disallow descriptor's re-use
+until it is fully processed.
+
+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/20200209163356.6439-3-digetx@gmail.com
+Signed-off-by: Vinod Koul <vkoul@kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ drivers/dma/tegra20-apb-dma.c |    2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/drivers/dma/tegra20-apb-dma.c
++++ b/drivers/dma/tegra20-apb-dma.c
+@@ -285,7 +285,7 @@ static struct tegra_dma_desc *tegra_dma_
+ 
+       /* Do not allocate if desc are waiting for ack */
+       list_for_each_entry(dma_desc, &tdc->free_dma_desc, node) {
+-              if (async_tx_test_ack(&dma_desc->txd)) {
++              if (async_tx_test_ack(&dma_desc->txd) && !dma_desc->cb_count) {
+                       list_del(&dma_desc->node);
+                       spin_unlock_irqrestore(&tdc->lock, flags);
+                       dma_desc->txd.flags = 0;

diff --git a/queue-4.4/series b/queue-4.4/series
index 6cbd26933318228f8d43fe466d664e201f264185..428d5659782900572010d4c9ac6d3ed02496aba3 100644 (file)
--- a/queue-4.4/series
+++ b/queue-4.4/series
@@ -57,3 +57,5 @@ fat-fix-uninit-memory-access-for-partial-initialized-inode.patch
 vt-selection-close-sel_buffer-race.patch
 vt-selection-push-console-lock-down.patch
 vt-selection-push-sel_lock-up.patch
+dmaengine-tegra-apb-fix-use-after-free.patch
+dmaengine-tegra-apb-prevent-race-conditions-of-tasklet-vs-free-list.patch