* [PATCH 4.19 045/110] x86/hyperv: Prevent potential NULL pointer dereference
[not found] <20190418160437.484158340@linuxfoundation.org>
@ 2019-04-18 17:56 ` Greg Kroah-Hartman
0 siblings, 0 replies; only message in thread
From: Greg Kroah-Hartman @ 2019-04-18 17:56 UTC (permalink / raw)
To: linux-kernel
Cc: Greg Kroah-Hartman, stable, Kangjie Lu, Thomas Gleixner,
Mukesh Ojha, K. Y. Srinivasan, pakki001, Haiyang Zhang,
Stephen Hemminger, Sasha Levin, Borislav Petkov, H. Peter Anvin,
linux-hyperv
[ Upstream commit 534c89c22e26b183d838294f0937ee092c82ad3a ]
The page allocation in hv_cpu_init() can fail, but the code does not
have a check for that.
Add a check and return -ENOMEM when the allocation fails.
[ tglx: Massaged changelog ]
Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>
Acked-by: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: pakki001@umn.edu
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: linux-hyperv@vger.kernel.org
Link: https://lkml.kernel.org/r/20190314054651.1315-1-kjlu@umn.edu
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/x86/hyperv/hv_init.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index 87abd5145cc9..3fb855155286 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -101,9 +101,13 @@ static int hv_cpu_init(unsigned int cpu)
u64 msr_vp_index;
struct hv_vp_assist_page **hvp = &hv_vp_assist_page[smp_processor_id()];
void **input_arg;
+ struct page *pg;
input_arg = (void **)this_cpu_ptr(hyperv_pcpu_input_arg);
- *input_arg = page_address(alloc_page(GFP_KERNEL));
+ pg = alloc_page(GFP_KERNEL);
+ if (unlikely(!pg))
+ return -ENOMEM;
+ *input_arg = page_address(pg);
hv_get_vp_index(msr_vp_index);
--
2.19.1
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