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From: Keith Busch <keith.busch@intel.com>
To: Vishal Verma <vishal.l.verma@intel.com>,
	Dave Jiang <dave.jiang@intel.com>,
Subject: [ndctl PATCH] ndctl: Work around kernel memory corruption
Date: Mon, 13 Aug 2018 14:31:53 -0600	[thread overview]
Message-ID: <20180813203153.562-1-keith.busch@intel.com> (raw)

Kernel commit efda1b5d87cb ("acpi, nfit, libnvdimm: fix / harden
ars_status output length handling") contained an incorrect ars status
output size calculation and may overrun the buffer provided by 4
bytes. This patch adds 4 bytes to the buffer the user space allocates
so that the kernel's overrun doesn't corrupt the application's heap.

See kernel patch for more details:


Signed-off-by: Keith Busch <keith.busch@intel.com>
 ndctl/lib/ars.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/ndctl/lib/ars.c b/ndctl/lib/ars.c
index c78e3bf..bd75131 100644
--- a/ndctl/lib/ars.c
+++ b/ndctl/lib/ars.c
@@ -133,7 +133,16 @@ NDCTL_EXPORT struct ndctl_cmd *ndctl_bus_cmd_new_ars_status(struct ndctl_cmd *ar
 	size = sizeof(*cmd) + ars_cap_cmd->max_ars_out;
-	cmd = calloc(1, size);
+	/*
+	 * Older kernels have a bug that miscalculates the output length of the
+	 * ars status and will overrun the provided buffer by 4 bytes,
+	 * corrupting the memory. Add an additional 4 bytes in the allocation
+	 * size to prevent that corruption. See kernel patch for more details:
+	 *
+	 *   https://patchwork.kernel.org/patch/10563103/
+	 */
+	cmd = calloc(1, size + 4);
 	if (!cmd)
 		return NULL;

Linux-nvdimm mailing list

             reply	other threads:[~2018-08-13 20:31 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-08-13 20:31 Keith Busch [this message]
2018-08-13 20:32 ` [ndctl PATCH] ndctl: Work around kernel memory corruption Dave Jiang

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