From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Viresh Kumar <viresh.kumar@linaro.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jason Gunthorpe <jgg@mellanox.com>,
Sasha Levin <sashal@kernel.org>,
linux-rdma@vger.kernel.org
Subject: [PATCH AUTOSEL 4.14 110/130] RDMA/qib: Validate ->show()/store() callbacks before calling them
Date: Tue, 10 Dec 2019 17:02:41 -0500 [thread overview]
Message-ID: <20191210220301.13262-110-sashal@kernel.org> (raw)
In-Reply-To: <20191210220301.13262-1-sashal@kernel.org>
From: Viresh Kumar <viresh.kumar@linaro.org>
[ Upstream commit 7ee23491b39259ae83899dd93b2a29ef0f22f0a7 ]
The permissions of the read-only or write-only sysfs files can be
changed (as root) and the user can then try to read a write-only file or
write to a read-only file which will lead to kernel crash here.
Protect against that by always validating the show/store callbacks.
Link: https://lore.kernel.org/r/d45cc26361a174ae12dbb86c994ef334d257924b.1573096807.git.viresh.kumar@linaro.org
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/infiniband/hw/qib/qib_sysfs.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/infiniband/hw/qib/qib_sysfs.c b/drivers/infiniband/hw/qib/qib_sysfs.c
index ca2638d8f35ef..d831f3e61ae8f 100644
--- a/drivers/infiniband/hw/qib/qib_sysfs.c
+++ b/drivers/infiniband/hw/qib/qib_sysfs.c
@@ -301,6 +301,9 @@ static ssize_t qib_portattr_show(struct kobject *kobj,
struct qib_pportdata *ppd =
container_of(kobj, struct qib_pportdata, pport_kobj);
+ if (!pattr->show)
+ return -EIO;
+
return pattr->show(ppd, buf);
}
@@ -312,6 +315,9 @@ static ssize_t qib_portattr_store(struct kobject *kobj,
struct qib_pportdata *ppd =
container_of(kobj, struct qib_pportdata, pport_kobj);
+ if (!pattr->store)
+ return -EIO;
+
return pattr->store(ppd, buf, len);
}
--
2.20.1
prev parent reply other threads:[~2019-12-10 22:05 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20191210220301.13262-1-sashal@kernel.org>
2019-12-10 22:01 ` [PATCH AUTOSEL 4.14 011/130] IB/iser: bound protection_sg size by data_sg size Sasha Levin
2019-12-10 22:01 ` [PATCH AUTOSEL 4.14 061/130] RDMA/qedr: Fix memory leak in user qp and mr Sasha Levin
2019-12-10 22:02 ` Sasha Levin [this message]
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