From c57d948e512ac87016b1b42e40cecfcc20543ab6 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Thu, 14 Feb 2019 11:08:48 +0800 Subject: [PATCH] arm64: force_signal_inject: WARN if called from kernel context mainline inclusion from mainline-4.20 commit 8a60419d3676 category: bugfix bugzilla: 5607 CVE: NA ------------------------------------------------- force_signal_inject() is designed to send a fatal signal to userspace, so WARN if the current pt_regs indicates a kernel context. This can currently happen for the undefined instruction trap, so patch that up so we always BUG() if we didn't have a handler. Signed-off-by: Will Deacon Signed-off-by: Catalin Marinas (cherry picked from commit 8a60419d36762a1131c2b29f7bd14371db4df1b5) Signed-off-by: Xie XiuQi Reviewed-by: Cheng Jian Signed-off-by: Yang Yingliang --- arch/arm64/kernel/traps.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index b9da093e0341..bfaaba50507a 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -354,6 +354,9 @@ void force_signal_inject(int signal, int code, unsigned long address) const char *desc; struct pt_regs *regs = current_pt_regs(); + if (WARN_ON(!user_mode(regs))) + return; + clear_siginfo(&info); switch (signal) { @@ -408,8 +411,8 @@ asmlinkage void __exception do_undefinstr(struct pt_regs *regs) if (call_undef_hook(regs) == 0) return; - force_signal_inject(SIGILL, ILL_ILLOPC, regs->pc); BUG_ON(!user_mode(regs)); + force_signal_inject(SIGILL, ILL_ILLOPC, regs->pc); } void cpu_enable_cache_maint_trap(const struct arm64_cpu_capabilities *__unused) -- GitLab