Messages in this thread Patch in this message | | | From | Luis Henriques <> | Subject | [PATCH 3.11 184/198] target: Explicitly clear ramdisk_mcp backend pages | Date | Thu, 3 Jul 2014 10:20:27 +0100 |
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3.11.10.13 -stable review patch. If anyone has any objections, please let me know.
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From: Nicholas Bellinger <nab@linux-iscsi.org>
This patch changes rd_allocate_sgl_table() to explicitly clear ramdisk_mcp backend memory pages by passing __GFP_ZERO into alloc_pages().
This addresses a potential security issue where reading from a ramdisk_mcp could return sensitive information, and follows what >= v3.15 does to explicitly clear ramdisk_mcp memory at backend device initialization time.
[ Note that a different patch to address the same issue went in during v3.15-rc1 (commit 4442dc8a), but includes a bunch of other changes that don't strictly apply to fixing the bug.
This is a one-liner that addresses the bug for all <= v3.14 versions. ]
Reported-by: Jorge Daniel Sequeira Matias <jdsm@tecnico.ulisboa.pt> Cc: Jorge Daniel Sequeira Matias <jdsm@tecnico.ulisboa.pt> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- drivers/target/target_core_rd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/target/target_core_rd.c b/drivers/target/target_core_rd.c index 51127d15d5c5..d71cdbed413b 100644 --- a/drivers/target/target_core_rd.c +++ b/drivers/target/target_core_rd.c @@ -179,7 +179,7 @@ static int rd_build_device_space(struct rd_dev *rd_dev) - 1; for (j = 0; j < sg_per_table; j++) { - pg = alloc_pages(GFP_KERNEL, 0); + pg = alloc_pages(GFP_KERNEL | __GFP_ZERO, 0); if (!pg) { pr_err("Unable to allocate scatterlist" " pages for struct rd_dev_sg_table\n"); -- 1.9.1
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