This is a note to let you know that I've just added the patch titled
device-dax: check devm_nsio_enable() return value
to the 4.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
device-dax-check-devm_nsio_enable-return-value.patch
and it can be found in the queue-4.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 6a84fb4b4e439a8ef0ce19ec7e7661ad76f655c9 Mon Sep 17 00:00:00 2001
From: Dan Williams <dan.j.williams@xxxxxxxxx>
Date: Fri, 28 Oct 2016 14:34:51 -0700
Subject: device-dax: check devm_nsio_enable() return value
From: Dan Williams <dan.j.williams@xxxxxxxxx>
commit 6a84fb4b4e439a8ef0ce19ec7e7661ad76f655c9 upstream.
If the dax_pmem driver is passed a resource that is already busy the
driver probe attempt should fail with a message like the following:
dax_pmem dax0.1: could not reserve region [mem 0x100000000-0x11fffffff]
However, if we do not catch the error we crash for the obvious reason of
accessing memory that is not mapped.
BUG: unable to handle kernel paging request at ffffc90020001000
IP: [<ffffffff81496712>] __memcpy+0x12/0x20
[..]
Call Trace:
[<ffffffff815c4960>] ? nsio_rw_bytes+0x60/0x180
[<ffffffff815c6045>] nd_pfn_validate+0x75/0x320
[<ffffffff815c63a9>] nvdimm_setup_pfn+0xb9/0x5d0
[<ffffffff815c48ef>] ? devm_nsio_enable+0xff/0x110
[<ffffffff815cb699>] dax_pmem_probe+0x59/0x260
Fixes: ab68f2622136 ("/dev/dax, pmem: direct access to persistent memory")
Reported-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/dax/pmem.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--- a/drivers/dax/pmem.c
+++ b/drivers/dax/pmem.c
@@ -77,7 +77,9 @@ static int dax_pmem_probe(struct device
nsio = to_nd_namespace_io(&ndns->dev);
/* parse the 'pfn' info block via ->rw_bytes */
- devm_nsio_enable(dev, nsio);
+ rc = devm_nsio_enable(dev, nsio);
+ if (rc)
+ return rc;
altmap = nvdimm_setup_pfn(nd_pfn, &res, &__altmap);
if (IS_ERR(altmap))
return PTR_ERR(altmap);
Patches currently in stable-queue which might be from dan.j.williams@xxxxxxxxx are
queue-4.8/device-dax-fail-all-private-mapping-attempts.patch
queue-4.8/device-dax-check-devm_nsio_enable-return-value.patch
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