4.4-stable review patch. If anyone has any objections, please let me know.
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From: "jie@chenjie6@huwei.com" <jie@chenjie6@huwei.com>
[ Upstream commit 24eee1e4c47977bdfb71d6f15f6011e7b6188d04 ]
ioremap_prot() can return NULL which could lead to an oops.
Link: http://lkml.kernel.org/r/1533195441-58594-1-git-send-email-chenjie6@huawei.c... Signed-off-by: chen jie chenjie6@huawei.com Reviewed-by: Andrew Morton akpm@linux-foundation.org Cc: Li Zefan lizefan@huawei.com Cc: chenjie chenjie6@huawei.com Cc: Yang Shi shy828301@gmail.com Cc: Alexey Dobriyan adobriyan@gmail.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- mm/memory.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/mm/memory.c +++ b/mm/memory.c @@ -3701,6 +3701,9 @@ int generic_access_phys(struct vm_area_s return -EINVAL;
maddr = ioremap_prot(phys_addr, PAGE_ALIGN(len + offset), prot); + if (!maddr) + return -ENOMEM; + if (write) memcpy_toio(maddr + offset, buf, len); else