3.19.8-ckt2 -stable review patch.  If anyone has any objections, please let me 
know.

------------------

From: Xi Wang <[email protected]>

commit 1e4df6b7208140f3c49f316d33a409d3a161f350 upstream.

Consider "(u64)insn1.imm << 32 | imm" in the arm64 JIT.  Since imm is
signed 32-bit, it is sign-extended to 64-bit, losing the high 32 bits.
The fix is to convert imm to u32 first, which will be zero-extended to
u64 implicitly.

Cc: Zi Shen Lim <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Catalin Marinas <[email protected]>
Fixes: 30d3d94cc3d5 ("arm64: bpf: add 'load 64-bit immediate' instruction")
Signed-off-by: Xi Wang <[email protected]>
[will: removed non-arm64 bits and redundant casting]
Signed-off-by: Will Deacon <[email protected]>
Signed-off-by: Kamal Mostafa <[email protected]>
---
 arch/arm64/net/bpf_jit_comp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c
index edba042..dc6a484 100644
--- a/arch/arm64/net/bpf_jit_comp.c
+++ b/arch/arm64/net/bpf_jit_comp.c
@@ -487,7 +487,7 @@ emit_cond_jmp:
                        return -EINVAL;
                }
 
-               imm64 = (u64)insn1.imm << 32 | imm;
+               imm64 = (u64)insn1.imm << 32 | (u32)imm;
                emit_a64_mov_i64(dst, imm64, ctx);
 
                return 1;
-- 
1.9.1

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