4.4-stable review patch. If anyone has any objections, please let me know.
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From: Heiko Carstens heiko.carstens@de.ibm.com
commit 5c50538752af7968f53924b22dede8ed4ce4cb3b upstream.
The e7 opcode table does not have an end marker. Hence when trying to find an unknown e7 instruction the code will access memory behind the table until it finds something that matches the opcode, or the kernel crashes, whatever comes first.
This affects not only the in-kernel disassembler but also uprobes and kprobes which refuse to set a probe on unknown instructions, and therefore search the opcode tables to figure out if instructions are known or not.
Fixes: 3585cb0280654 ("s390/disassembler: add vector instructions") Signed-off-by: Heiko Carstens heiko.carstens@de.ibm.com Signed-off-by: Martin Schwidefsky schwidefsky@de.ibm.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/s390/kernel/dis.c | 1 + 1 file changed, 1 insertion(+)
--- a/arch/s390/kernel/dis.c +++ b/arch/s390/kernel/dis.c @@ -1549,6 +1549,7 @@ static struct s390_insn opcode_e7[] = { { "vfsq", 0xce, INSTR_VRR_VV000MM }, { "vfs", 0xe2, INSTR_VRR_VVV00MM }, { "vftci", 0x4a, INSTR_VRI_VVIMM }, + { "", 0, INSTR_INVALID } };
static struct s390_insn opcode_eb[] = {