From: Naveen N Rao Date: Thu, 23 Nov 2023 07:17:05 +0000 (+0530) Subject: powerpc/lib: Validate size for vector operations X-Git-Tag: v6.6.16~315 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=28b8ba8eebf26f66d9f2df4ba550b6b3b136082c;p=thirdparty%2Fkernel%2Fstable.git 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 --- diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c index a4ab8625061a6..6af97dc0f6d5a 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 */