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 <naveen@kernel.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Build-tested-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231123071705.397625-1-naveen@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Naveen N Rao 2023-11-23 12:47:05 +05:30 committed by Greg Kroah-Hartman
parent 0be5614f26
commit abd26515d4
1 changed files with 10 additions and 0 deletions

View File

@ -586,6 +586,8 @@ static int do_fp_load(struct instruction_op *op, unsigned long ea,
} u; } u;
nb = GETSIZE(op->type); nb = GETSIZE(op->type);
if (nb > sizeof(u))
return -EINVAL;
if (!address_ok(regs, ea, nb)) if (!address_ok(regs, ea, nb))
return -EFAULT; return -EFAULT;
rn = op->reg; rn = op->reg;
@ -636,6 +638,8 @@ static int do_fp_store(struct instruction_op *op, unsigned long ea,
} u; } u;
nb = GETSIZE(op->type); nb = GETSIZE(op->type);
if (nb > sizeof(u))
return -EINVAL;
if (!address_ok(regs, ea, nb)) if (!address_ok(regs, ea, nb))
return -EFAULT; return -EFAULT;
rn = op->reg; rn = op->reg;
@ -680,6 +684,9 @@ static nokprobe_inline int do_vec_load(int rn, unsigned long ea,
u8 b[sizeof(__vector128)]; u8 b[sizeof(__vector128)];
} u = {}; } u = {};
if (size > sizeof(u))
return -EINVAL;
if (!address_ok(regs, ea & ~0xfUL, 16)) if (!address_ok(regs, ea & ~0xfUL, 16))
return -EFAULT; return -EFAULT;
/* align to multiple of size */ /* 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)]; u8 b[sizeof(__vector128)];
} u; } u;
if (size > sizeof(u))
return -EINVAL;
if (!address_ok(regs, ea & ~0xfUL, 16)) if (!address_ok(regs, ea & ~0xfUL, 16))
return -EFAULT; return -EFAULT;
/* align to multiple of size */ /* align to multiple of size */