From b907a8622e39eecfc4b243f3be3ad26559d1faee Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Andr=C3=A9=20Fabian=20Silva=20Delgado?= Date: Mon, 27 Jun 2016 21:01:09 -0300 Subject: Linux-libre 4.6.3-gnu --- arch/sparc/kernel/signal32.c | 46 +++++++++++++++++++++++++++++--------------- 1 file changed, 30 insertions(+), 16 deletions(-) (limited to 'arch/sparc/kernel/signal32.c') diff --git a/arch/sparc/kernel/signal32.c b/arch/sparc/kernel/signal32.c index 3c25241fa..ebd0bfe25 100644 --- a/arch/sparc/kernel/signal32.c +++ b/arch/sparc/kernel/signal32.c @@ -138,12 +138,24 @@ int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from) return 0; } +/* Checks if the fp is valid. We always build signal frames which are + * 16-byte aligned, therefore we can always enforce that the restore + * frame has that property as well. + */ +static bool invalid_frame_pointer(void __user *fp, int fplen) +{ + if ((((unsigned long) fp) & 15) || + ((unsigned long)fp) > 0x100000000ULL - fplen) + return true; + return false; +} + void do_sigreturn32(struct pt_regs *regs) { struct signal_frame32 __user *sf; compat_uptr_t fpu_save; compat_uptr_t rwin_save; - unsigned int psr; + unsigned int psr, ufp; unsigned int pc, npc; sigset_t set; compat_sigset_t seta; @@ -158,11 +170,16 @@ void do_sigreturn32(struct pt_regs *regs) sf = (struct signal_frame32 __user *) regs->u_regs[UREG_FP]; /* 1. Make sure we are not getting garbage from the user */ - if (!access_ok(VERIFY_READ, sf, sizeof(*sf)) || - (((unsigned long) sf) & 3)) + if (invalid_frame_pointer(sf, sizeof(*sf))) + goto segv; + + if (get_user(ufp, &sf->info.si_regs.u_regs[UREG_FP])) + goto segv; + + if (ufp & 0x7) goto segv; - if (get_user(pc, &sf->info.si_regs.pc) || + if (__get_user(pc, &sf->info.si_regs.pc) || __get_user(npc, &sf->info.si_regs.npc)) goto segv; @@ -227,7 +244,7 @@ segv: asmlinkage void do_rt_sigreturn32(struct pt_regs *regs) { struct rt_signal_frame32 __user *sf; - unsigned int psr, pc, npc; + unsigned int psr, pc, npc, ufp; compat_uptr_t fpu_save; compat_uptr_t rwin_save; sigset_t set; @@ -242,11 +259,16 @@ asmlinkage void do_rt_sigreturn32(struct pt_regs *regs) sf = (struct rt_signal_frame32 __user *) regs->u_regs[UREG_FP]; /* 1. Make sure we are not getting garbage from the user */ - if (!access_ok(VERIFY_READ, sf, sizeof(*sf)) || - (((unsigned long) sf) & 3)) + if (invalid_frame_pointer(sf, sizeof(*sf))) goto segv; - if (get_user(pc, &sf->regs.pc) || + if (get_user(ufp, &sf->regs.u_regs[UREG_FP])) + goto segv; + + if (ufp & 0x7) + goto segv; + + if (__get_user(pc, &sf->regs.pc) || __get_user(npc, &sf->regs.npc)) goto segv; @@ -307,14 +329,6 @@ segv: force_sig(SIGSEGV, current); } -/* Checks if the fp is valid */ -static int invalid_frame_pointer(void __user *fp, int fplen) -{ - if ((((unsigned long) fp) & 7) || ((unsigned long)fp) > 0x100000000ULL - fplen) - return 1; - return 0; -} - static void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, unsigned long framesize) { unsigned long sp; -- cgit v1.2.3