Messages in this thread | | | From | Jim Quinlan <> | Date | Mon, 4 Jan 2021 10:55:58 -0500 | Subject | Re: [PATCH] drivers core: Free dma_range_map when driver probe failed |
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> Subject: [PATCH] drivers core: Free dma_range_map when driver probe failed > > There will be memory leak if driver probe failed. Trace as below: > backtrace: > [<000000002415258f>] kmemleak_alloc+0x3c/0x50 > [<00000000f447ebe4>] __kmalloc+0x208/0x530 > [<0000000048bc7b3a>] of_dma_get_range+0xe4/0x1b0 > [<0000000041e39065>] of_dma_configure_id+0x58/0x27c > [<000000006356866a>] platform_dma_configure+0x2c/0x40 > ...... > [<000000000afcf9b5>] ret_from_fork+0x10/0x3c > > This issue is introduced by commit e0d072782c73("dma-mapping: > introduce DMA range map, supplanting dma_pfn_offset "). It doesn't > free dma_range_map when driver probe failed and cause above > memory leak. So, add code to free it in error path. > > Fixes: e0d072782c73("dma-mapping: introduce DMA range map, supplanting > dma_pfn_offset ") > Cc: stable@vger.kernel.org > Signed-off-by: Meng Li <Meng.Li@windriver.com> > --- > drivers/base/dd.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/base/dd.c b/drivers/base/dd.c > index 148e81969e04..8e4871aa34bc 100644 > --- a/drivers/base/dd.c > +++ b/drivers/base/dd.c > @@ -612,6 +612,7 @@ static int really_probe(struct device *dev, struct > device_driver *drv) > else if (drv->remove) > drv->remove(dev); > probe_failed: > + kfree(dev->dma_range_map); > if (dev->bus) > blocking_notifier_call_chain(&dev->bus->p->bus_notifier, > BUS_NOTIFY_DRIVER_NOT_BOUND, dev); > -- > 2.17.1 > > --
Hi Meng,
Sorry for the delay -- I was on vacation. I agree with you -- thanks. However, note that in function device_release() in drivers/base/core.c there is this line:
kfree(dev->dma_range_map);
Won't this also be called if all of the appropriate drivers' probes fail for this device, effecting a double kfree? Perhaps your patch could also set "dev->dma_range_map" to NULL after calling kfree()?
Thanks much, Jim Quinlan Broadcom STB
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