From abd26515d4b767ba48241eea77b28ce0872aef3e Mon Sep 17 00:00:00 2001 From: Naveen N Rao Date: Thu, 23 Nov 2023 12:47:05 +0530 Subject: [PATCH] powerpc/lib: Validate size for vector operations [ Upstream commit 8f9abaa6d7de0a70fc68acaedce290c1f96e2e59 ] Some of the fp/vmx code in sstep.c assume a certain maximum size for the instructions being emulated. The size of those operations however is determined separately in analyse_instr(). Add a check to validate the assumption on the maximum size of the operations, so as to prevent any unintended kernel stack corruption. Signed-off-by: Naveen N Rao Reviewed-by: Gustavo A. R. Silva Build-tested-by: Gustavo A. R. Silva Signed-off-by: Michael Ellerman Link: https://msgid.link/20231123071705.397625-1-naveen@kernel.org Signed-off-by: Sasha Levin --- arch/powerpc/lib/sstep.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c index 398b5694aeb7..ec30af8eadb7 100644 --- a/arch/powerpc/lib/sstep.c +++ b/arch/powerpc/lib/sstep.c @@ -586,6 +586,8 @@ static int do_fp_load(struct instruction_op *op, unsigned long ea, } u; nb = GETSIZE(op->type); + if (nb > sizeof(u)) + return -EINVAL; if (!address_ok(regs, ea, nb)) return -EFAULT; rn = op->reg; @@ -636,6 +638,8 @@ static int do_fp_store(struct instruction_op *op, unsigned long ea, } u; nb = GETSIZE(op->type); + if (nb > sizeof(u)) + return -EINVAL; if (!address_ok(regs, ea, nb)) return -EFAULT; rn = op->reg; @@ -680,6 +684,9 @@ static nokprobe_inline int do_vec_load(int rn, unsigned long ea, u8 b[sizeof(__vector128)]; } u = {}; + if (size > sizeof(u)) + return -EINVAL; + if (!address_ok(regs, ea & ~0xfUL, 16)) return -EFAULT; /* align to multiple of size */ @@ -707,6 +714,9 @@ static nokprobe_inline int do_vec_store(int rn, unsigned long ea, u8 b[sizeof(__vector128)]; } u; + if (size > sizeof(u)) + return -EINVAL; + if (!address_ok(regs, ea & ~0xfUL, 16)) return -EFAULT; /* align to multiple of size */