diff options
| author | Lukas Wunner <lukas@wunner.de> | 2019-12-05 12:54:49 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-01-12 11:24:13 +0100 |
| commit | 189ca92688236a1f72fb5a088e9bb10cd2b7ba15 (patch) | |
| tree | 2cfc22c616a0cecde02bf48d7af5f9b950ba6291 /include | |
| parent | 05a613df7f37c72162ebc0093c8ade476da283a1 (diff) | |
dmaengine: Fix access to uninitialized dma_slave_caps
commit 53a256a9b925b47c7e67fc1f16ca41561a7b877c upstream.
dmaengine_desc_set_reuse() allocates a struct dma_slave_caps on the
stack, populates it using dma_get_slave_caps() and then accesses one
of its members.
However dma_get_slave_caps() may fail and this isn't accounted for,
leading to a legitimate warning of gcc-4.9 (but not newer versions):
In file included from drivers/spi/spi-bcm2835.c:19:0:
drivers/spi/spi-bcm2835.c: In function 'dmaengine_desc_set_reuse':
>> include/linux/dmaengine.h:1370:10: warning: 'caps.descriptor_reuse' is used uninitialized in this function [-Wuninitialized]
if (caps.descriptor_reuse) {
Fix it, thereby also silencing the gcc-4.9 warning.
The issue has been present for 4 years but surfaces only now that
the first caller of dmaengine_desc_set_reuse() has been added in
spi-bcm2835.c. Another user of reusable DMA descriptors has existed
for a while in pxa_camera.c, but it sets the DMA_CTRL_REUSE flag
directly instead of calling dmaengine_desc_set_reuse(). Nevertheless,
tag this commit for stable in case there are out-of-tree users.
Fixes: 272420214d26 ("dmaengine: Add DMA_CTRL_REUSE")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: stable@vger.kernel.org # v4.3+
Link: https://lore.kernel.org/r/ca92998ccc054b4f2bfd60ef3adbab2913171eac.1575546234.git.lukas@wunner.de
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/dmaengine.h | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index cc535a478bae..710f269764dc 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -1358,8 +1358,11 @@ static inline int dma_get_slave_caps(struct dma_chan *chan, static inline int dmaengine_desc_set_reuse(struct dma_async_tx_descriptor *tx) { struct dma_slave_caps caps; + int ret; - dma_get_slave_caps(tx->chan, &caps); + ret = dma_get_slave_caps(tx->chan, &caps); + if (ret) + return ret; if (caps.descriptor_reuse) { tx->flags |= DMA_CTRL_REUSE; |