From b907a8622e39eecfc4b243f3be3ad26559d1faee Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Mon, 27 Jun 2016 21:01:09 -0300 Subject: Linux-libre 4.6.3-gnu --- arch/sparc/kernel/signal_32.c | 41 ++++++++++++++++++++++++++--------------- 1 file changed, 26 insertions(+), 15 deletions(-) (limited to 'arch/sparc/kernel/signal_32.c') diff --git a/arch/sparc/kernel/signal_32.c b/arch/sparc/kernel/signal_32.c index 52aa5e4ce..c3c12efe0 100644 --- a/arch/sparc/kernel/signal_32.c +++ b/arch/sparc/kernel/signal_32.c @@ -60,10 +60,22 @@ struct rt_signal_frame { #define SF_ALIGNEDSZ (((sizeof(struct signal_frame) + 7) & (~7))) #define RT_ALIGNEDSZ (((sizeof(struct rt_signal_frame) + 7) & (~7))) +/* 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 inline bool invalid_frame_pointer(void __user *fp, int fplen) +{ + if ((((unsigned long) fp) & 15) || !__access_ok((unsigned long)fp, fplen)) + return true; + + return false; +} + asmlinkage void do_sigreturn(struct pt_regs *regs) { + unsigned long up_psr, pc, npc, ufp; struct signal_frame __user *sf; - unsigned long up_psr, pc, npc; sigset_t set; __siginfo_fpu_t __user *fpu_save; __siginfo_rwin_t __user *rwin_save; @@ -77,10 +89,13 @@ asmlinkage void do_sigreturn(struct pt_regs *regs) sf = (struct signal_frame __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))) + if (!invalid_frame_pointer(sf, sizeof(*sf))) + goto segv_and_exit; + + if (get_user(ufp, &sf->info.si_regs.u_regs[UREG_FP])) goto segv_and_exit; - if (((unsigned long) sf) & 3) + if (ufp & 0x7) goto segv_and_exit; err = __get_user(pc, &sf->info.si_regs.pc); @@ -127,7 +142,7 @@ segv_and_exit: asmlinkage void do_rt_sigreturn(struct pt_regs *regs) { struct rt_signal_frame __user *sf; - unsigned int psr, pc, npc; + unsigned int psr, pc, npc, ufp; __siginfo_fpu_t __user *fpu_save; __siginfo_rwin_t __user *rwin_save; sigset_t set; @@ -135,8 +150,13 @@ asmlinkage void do_rt_sigreturn(struct pt_regs *regs) synchronize_user_stack(); sf = (struct rt_signal_frame __user *) regs->u_regs[UREG_FP]; - if (!access_ok(VERIFY_READ, sf, sizeof(*sf)) || - (((unsigned long) sf) & 0x03)) + if (!invalid_frame_pointer(sf, sizeof(*sf))) + goto segv; + + if (get_user(ufp, &sf->regs.u_regs[UREG_FP])) + goto segv; + + if (ufp & 0x7) goto segv; err = __get_user(pc, &sf->regs.pc); @@ -178,15 +198,6 @@ segv: force_sig(SIGSEGV, current); } -/* Checks if the fp is valid */ -static inline int invalid_frame_pointer(void __user *fp, int fplen) -{ - if ((((unsigned long) fp) & 7) || !__access_ok((unsigned long)fp, fplen)) - return 1; - - return 0; -} - static inline void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, unsigned long framesize) { unsigned long sp = regs->u_regs[UREG_FP]; -- cgit v1.2.3-54-g00ecf