[PATCH 14/14] powerpc/rtas: Consolidate and improve checking for rtas callers
From: Nicholas Piggin <npiggin@gmail.com>
Date: 2022-03-08 14:00:25
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
Add range checking from the rtas syscall, and other error checks and warnings to kernel callers, so problems can be found and fixed. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> --- arch/powerpc/kernel/rtas.c | 23 +++++++++++++++++------ 1 file changed, 17 insertions(+), 6 deletions(-)
diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
index adf4892aeecd..7f8a3fd685f9 100644
--- a/arch/powerpc/kernel/rtas.c
+++ b/arch/powerpc/kernel/rtas.c@@ -428,6 +428,23 @@ static int notrace va_raw_rtas_call(struct rtas_args *args, int token, { int i; + if (!irqs_disabled()) { + WARN_ON_ONCE(1); + return -1; + } + + if (!rtas.entry || token == RTAS_UNKNOWN_SERVICE) { + WARN_ON_ONCE(1); + return -1; + } + + if (nargs >= ARRAY_SIZE(args->args) + || nret > ARRAY_SIZE(args->args) + || nargs + nret > ARRAY_SIZE(args->args)) { + WARN_ON_ONCE(1); + return -1; + } + args->token = cpu_to_be32(token); args->nargs = cpu_to_be32(nargs); args->nret = cpu_to_be32(nret);
@@ -476,9 +493,6 @@ int rtas_call(int token, int nargs, int nret, int *outputs, ...) char *buff_copy = NULL; int ret; - if (!rtas.entry || token == RTAS_UNKNOWN_SERVICE) - return -1; - if ((mfmsr() & (MSR_IR|MSR_DR)) != (MSR_IR|MSR_DR)) { WARN_ON_ONCE(1); return -1;
@@ -955,9 +969,6 @@ int rtas_call_reentrant(int token, int nargs, int nret, int *outputs, ...) unsigned long flags; int ret; - if (!rtas.entry || token == RTAS_UNKNOWN_SERVICE) - return -1; - local_irq_save(flags); preempt_disable();
--
2.23.0