From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Geert Uytterhoeven <geert+renesas@glider.be>,
Eugeniu Rosca <erosca@de.adit-jv.com>,
Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>,
Vinod Koul <vkoul@kernel.org>, Sasha Levin <sashal@kernel.org>,
dmaengine@vger.kernel.org
Subject: [PATCH AUTOSEL 4.4 05/23] dmaengine: rcar-dmac: Reject zero-length slave DMA requests
Date: Fri, 26 Jul 2019 09:45:04 -0400 [thread overview]
Message-ID: <20190726134522.13308-5-sashal@kernel.org> (raw)
In-Reply-To: <20190726134522.13308-1-sashal@kernel.org>
From: Geert Uytterhoeven <geert+renesas@glider.be>
[ Upstream commit 78efb76ab4dfb8f74f290ae743f34162cd627f19 ]
While the .device_prep_slave_sg() callback rejects empty scatterlists,
it still accepts single-entry scatterlists with a zero-length segment.
These may happen if a driver calls dmaengine_prep_slave_single() with a
zero len parameter. The corresponding DMA request will never complete,
leading to messages like:
rcar-dmac e7300000.dma-controller: Channel Address Error happen
and DMA timeouts.
Although requesting a zero-length DMA request is a driver bug, rejecting
it early eases debugging. Note that the .device_prep_dma_memcpy()
callback already rejects requests to copy zero bytes.
Reported-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Analyzed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/dma/sh/rcar-dmac.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c
index 2b36d1c63aa5..956189a1ba81 100644
--- a/drivers/dma/sh/rcar-dmac.c
+++ b/drivers/dma/sh/rcar-dmac.c
@@ -1030,7 +1030,7 @@ rcar_dmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
dma_addr_t dev_addr;
/* Someone calling slave DMA on a generic channel? */
- if (rchan->mid_rid < 0 || !sg_len) {
+ if (rchan->mid_rid < 0 || !sg_len || !sg_dma_len(sgl)) {
dev_warn(chan->device->dev,
"%s: bad parameter: len=%d, id=%d\n",
__func__, sg_len, rchan->mid_rid);
--
2.20.1
next prev parent reply other threads:[~2019-07-26 13:48 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-26 13:45 [PATCH AUTOSEL 4.4 01/23] ARM: riscpc: fix DMA Sasha Levin
2019-07-26 13:45 ` [PATCH AUTOSEL 4.4 02/23] ARM: dts: rockchip: Mark that the rk3288 timer might stop in suspend Sasha Levin
2019-07-26 13:45 ` [PATCH AUTOSEL 4.4 03/23] kernel/module.c: Only return -EEXIST for modules that have finished loading Sasha Levin
2019-07-26 13:45 ` [PATCH AUTOSEL 4.4 04/23] MIPS: lantiq: Fix bitfield masking Sasha Levin
2019-07-26 13:45 ` Sasha Levin [this message]
2019-07-26 13:45 ` [PATCH AUTOSEL 4.4 06/23] fs/adfs: super: fix use-after-free bug Sasha Levin
2019-07-26 13:45 ` [PATCH AUTOSEL 4.4 07/23] btrfs: fix minimum number of chunk errors for DUP Sasha Levin
2019-07-26 13:45 ` [PATCH AUTOSEL 4.4 08/23] ceph: fix improper use of smp_mb__before_atomic() Sasha Levin
2019-07-26 13:45 ` [PATCH AUTOSEL 4.4 09/23] scsi: zfcp: fix GCC compiler warning emitted with -Wmaybe-uninitialized Sasha Levin
2019-07-26 13:45 ` [PATCH AUTOSEL 4.4 10/23] ACPI: fix false-positive -Wuninitialized warning Sasha Levin
2019-07-26 13:45 ` [PATCH AUTOSEL 4.4 11/23] ISDN: hfcsusb: checking idx of ep configuration Sasha Levin
2019-07-26 13:45 ` [PATCH AUTOSEL 4.4 12/23] be2net: Signal that the device cannot transmit during reconfiguration Sasha Levin
2019-07-26 13:45 ` [PATCH AUTOSEL 4.4 13/23] x86/apic: Silence -Wtype-limits compiler warnings Sasha Levin
2019-07-26 13:45 ` [PATCH AUTOSEL 4.4 14/23] x86: math-emu: Hide clang warnings for 16-bit overflow Sasha Levin
2019-07-26 13:45 ` [PATCH AUTOSEL 4.4 15/23] mm/cma.c: fail if fixed declaration can't be honored Sasha Levin
2019-07-26 13:45 ` [PATCH AUTOSEL 4.4 16/23] coda: add error handling for fget Sasha Levin
2019-07-26 13:45 ` [PATCH AUTOSEL 4.4 17/23] coda: fix build using bare-metal toolchain Sasha Levin
2019-07-26 13:45 ` [PATCH AUTOSEL 4.4 18/23] uapi linux/coda_psdev.h: move upc_req definition from uapi to kernel side headers Sasha Levin
2019-07-26 13:45 ` [PATCH AUTOSEL 4.4 19/23] drivers/pps/pps.c: clear offset flags in PPS_SETPARAMS ioctl Sasha Levin
2019-07-26 13:45 ` [PATCH AUTOSEL 4.4 20/23] ipc/mqueue.c: only perform resource calculation if user valid Sasha Levin
2019-07-26 13:45 ` [PATCH AUTOSEL 4.4 21/23] floppy: fix div-by-zero in setup_format_params Sasha Levin
2019-07-26 13:45 ` [PATCH AUTOSEL 4.4 22/23] floppy: fix out-of-bounds read in copy_buffer Sasha Levin
2019-07-26 13:45 ` [PATCH AUTOSEL 4.4 23/23] x86/kvm: Don't call kvm_spurious_fault() from .fixup Sasha Levin
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