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authorDmitry Osipenko <digetx@gmail.com>2020-02-09 19:33:38 +0300
committerVinod Koul <vkoul@kernel.org>2020-02-25 11:57:09 +0530
commit94788af4ed039476ff3527b0e6a12c1dc42cb022 (patch)
tree58432273a97553962e5a0214bcacdc9f4d732b8a /drivers/dma
parentd288bddd8374e0a043ac9dde64a1ae6a09411d74 (diff)
downloadlinux-94788af4ed039476ff3527b0e6a12c1dc42cb022.tar.bz2
dmaengine: tegra-apb: Fix use-after-free
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>
Diffstat (limited to 'drivers/dma')
-rw-r--r--drivers/dma/tegra20-apb-dma.c4
1 files changed, 0 insertions, 4 deletions
diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c
index 3a45079d11ec..319f31d27014 100644
--- a/drivers/dma/tegra20-apb-dma.c
+++ b/drivers/dma/tegra20-apb-dma.c
@@ -756,10 +756,6 @@ 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;