The siginfo structure has all manners of holes with the result that a structure initializer is not guaranteed to initialize all of the bits. As we have to copy the structure to userspace don't even try to use a structure initializer. Instead use clear_siginfo followed by initializing selected fields. This gives a guarantee that uninitialized kernel memory is not copied to userspace.
Signed-off-by: "Eric W. Biederman" <[email protected]> --- arch/arc/kernel/traps.c | 14 +++++++----- arch/arm64/kernel/debug-monitors.c | 13 ++++++----- arch/arm64/kernel/ptrace.c | 13 ++++++----- arch/m68k/mm/fault.c | 3 ++- arch/mips/kernel/traps.c | 29 ++++++++++++++++-------- arch/tile/kernel/single_step.c | 24 +++++++++++--------- arch/tile/kernel/traps.c | 4 +++- arch/tile/kernel/unaligned.c | 46 +++++++++++++++++++++----------------- kernel/signal.c | 3 ++- 9 files changed, 89 insertions(+), 60 deletions(-) diff --git a/arch/arc/kernel/traps.c b/arch/arc/kernel/traps.c index bcd7c9fc5d0f..c7206789e9ce 100644 --- a/arch/arc/kernel/traps.c +++ b/arch/arc/kernel/traps.c @@ -65,12 +65,14 @@ unhandled_exception(const char *str, struct pt_regs *regs, siginfo_t *info) #define DO_ERROR_INFO(signr, str, name, sicode) \ int name(unsigned long address, struct pt_regs *regs) \ { \ - siginfo_t info = { \ - .si_signo = signr, \ - .si_errno = 0, \ - .si_code = sicode, \ - .si_addr = (void __user *)address, \ - }; \ + siginfo_t info; \ + \ + clear_siginfo(&info); \ + info.si_signo = signr; \ + info.si_errno = 0; \ + info.si_code = sicode; \ + info.si_addr = (void __user *)address; \ + \ return unhandled_exception(str, regs, &info);\ } diff --git a/arch/arm64/kernel/debug-monitors.c b/arch/arm64/kernel/debug-monitors.c index a88b6ccebbb4..53781f5687c5 100644 --- a/arch/arm64/kernel/debug-monitors.c +++ b/arch/arm64/kernel/debug-monitors.c @@ -209,12 +209,13 @@ NOKPROBE_SYMBOL(call_step_hook); static void send_user_sigtrap(int si_code) { struct pt_regs *regs = current_pt_regs(); - siginfo_t info = { - .si_signo = SIGTRAP, - .si_errno = 0, - .si_code = si_code, - .si_addr = (void __user *)instruction_pointer(regs), - }; + siginfo_t info; + + clear_siginfo(&info); + info.si_signo = SIGTRAP; + info.si_errno = 0; + info.si_code = si_code; + info.si_addr = (void __user *)instruction_pointer(regs); if (WARN_ON(!user_mode(regs))) return; diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index 0a1cf830e4b3..95daa1478a7c 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -180,12 +180,13 @@ static void ptrace_hbptriggered(struct perf_event *bp, struct pt_regs *regs) { struct arch_hw_breakpoint *bkpt = counter_arch_bp(bp); - siginfo_t info = { - .si_signo = SIGTRAP, - .si_errno = 0, - .si_code = TRAP_HWBKPT, - .si_addr = (void __user *)(bkpt->trigger), - }; + siginfo_t info; + + clear_siginfo(&info); + info.si_signo = SIGTRAP; + info.si_errno = 0; + info.si_code = TRAP_HWBKPT; + info.si_addr = (void __user *)(bkpt->trigger); #ifdef CONFIG_COMPAT if (is_compat_task()) { diff --git a/arch/m68k/mm/fault.c b/arch/m68k/mm/fault.c index 127d7c1f2090..03253c4f8e6a 100644 --- a/arch/m68k/mm/fault.c +++ b/arch/m68k/mm/fault.c @@ -21,8 +21,9 @@ extern void die_if_kernel(char *, struct pt_regs *, long); int send_fault_sig(struct pt_regs *regs) { - siginfo_t siginfo = { 0, 0, 0, }; + siginfo_t siginfo; + clear_siginfo(&siginfo); siginfo.si_signo = current->thread.signo; siginfo.si_code = current->thread.code; siginfo.si_addr = (void *)current->thread.faddr; diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c index 5d19ed07e99d..0ae4a731cc12 100644 --- a/arch/mips/kernel/traps.c +++ b/arch/mips/kernel/traps.c @@ -699,11 +699,12 @@ static int simulate_sync(struct pt_regs *regs, unsigned int opcode) asmlinkage void do_ov(struct pt_regs *regs) { enum ctx_state prev_state; - siginfo_t info = { - .si_signo = SIGFPE, - .si_code = FPE_INTOVF, - .si_addr = (void __user *)regs->cp0_epc, - }; + siginfo_t info; + + clear_siginfo(&info); + info.si_signo = SIGFPE; + info.si_code = FPE_INTOVF; + info.si_addr = (void __user *)regs->cp0_epc; prev_state = exception_enter(); die_if_kernel("Integer overflow", regs); @@ -721,7 +722,11 @@ asmlinkage void do_ov(struct pt_regs *regs) void force_fcr31_sig(unsigned long fcr31, void __user *fault_addr, struct task_struct *tsk) { - struct siginfo si = { .si_addr = fault_addr, .si_signo = SIGFPE }; + struct siginfo si; + + clear_siginfo(&si); + si.si_addr = fault_addr; + si.si_signo = SIGFPE; if (fcr31 & FPU_CSR_INV_X) si.si_code = FPE_FLTINV; @@ -739,9 +744,10 @@ void force_fcr31_sig(unsigned long fcr31, void __user *fault_addr, int process_fpemu_return(int sig, void __user *fault_addr, unsigned long fcr31) { - struct siginfo si = { 0 }; + struct siginfo si; struct vm_area_struct *vma; + clear_siginfo(&si); switch (sig) { case 0: return 0; @@ -890,9 +896,10 @@ asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31) void do_trap_or_bp(struct pt_regs *regs, unsigned int code, int si_code, const char *str) { - siginfo_t info = { 0 }; + siginfo_t info; char b[40]; + clear_siginfo(&info); #ifdef CONFIG_KGDB_LOW_LEVEL_TRAP if (kgdb_ll_trap(DIE_TRAP, str, regs, code, current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP) @@ -1499,9 +1506,13 @@ asmlinkage void do_mdmx(struct pt_regs *regs) */ asmlinkage void do_watch(struct pt_regs *regs) { - siginfo_t info = { .si_signo = SIGTRAP, .si_code = TRAP_HWBKPT }; + siginfo_t info; enum ctx_state prev_state; + clear_siginfo(&info); + info.si_signo = SIGTRAP; + info.si_code = TRAP_HWBKPT; + prev_state = exception_enter(); /* * Clear WP (bit 22) bit of cause register so we don't loop diff --git a/arch/tile/kernel/single_step.c b/arch/tile/kernel/single_step.c index de3eae813e52..479d8033a801 100644 --- a/arch/tile/kernel/single_step.c +++ b/arch/tile/kernel/single_step.c @@ -163,11 +163,13 @@ static tilepro_bundle_bits rewrite_load_store_unaligned( * actual bad address in an SPR, which it doesn't. */ if (align_ctl == 0) { - siginfo_t info = { - .si_signo = SIGBUS, - .si_code = BUS_ADRALN, - .si_addr = addr - }; + siginfo_t info; + + clear_siginfo(&info); + info.si_signo = SIGBUS; + info.si_code = BUS_ADRALN; + info.si_addr = addr; + trace_unhandled_signal("unaligned trap", regs, (unsigned long)addr, SIGBUS); force_sig_info(info.si_signo, &info, current); @@ -210,11 +212,13 @@ static tilepro_bundle_bits rewrite_load_store_unaligned( } if (err) { - siginfo_t info = { - .si_signo = SIGBUS, - .si_code = BUS_ADRALN, - .si_addr = addr - }; + siginfo_t info; + + clear_siginfo(&info); + info.si_signo = SIGBUS; + info.si_code = BUS_ADRALN; + info.si_addr = addr; + trace_unhandled_signal("bad address for unaligned fixup", regs, (unsigned long)addr, SIGBUS); force_sig_info(info.si_signo, &info, current); diff --git a/arch/tile/kernel/traps.c b/arch/tile/kernel/traps.c index 9b08c6055f15..83a7186198d7 100644 --- a/arch/tile/kernel/traps.c +++ b/arch/tile/kernel/traps.c @@ -256,12 +256,14 @@ static int do_bpt(struct pt_regs *regs) void __kprobes do_trap(struct pt_regs *regs, int fault_num, unsigned long reason) { - siginfo_t info = { 0 }; + siginfo_t info; int signo, code; unsigned long address = 0; tile_bundle_bits instr; int is_kernel = !user_mode(regs); + clear_siginfo(&info); + /* Handle breakpoints, etc. */ if (is_kernel && fault_num == INT_ILL && do_bpt(regs)) return; diff --git a/arch/tile/kernel/unaligned.c b/arch/tile/kernel/unaligned.c index 8149c38f67b6..77a0b6b6a2a1 100644 --- a/arch/tile/kernel/unaligned.c +++ b/arch/tile/kernel/unaligned.c @@ -980,11 +980,13 @@ void jit_bundle_gen(struct pt_regs *regs, tilegx_bundle_bits bundle, } if ((align_ctl == 0) || unexpected) { - siginfo_t info = { - .si_signo = SIGBUS, - .si_code = BUS_ADRALN, - .si_addr = (unsigned char __user *)0 - }; + siginfo_t info; + + clear_siginfo(&info); + info.si_signo = SIGBUS; + info.si_code = BUS_ADRALN; + info.si_addr = (unsigned char __user *)0; + if (unaligned_printk) pr_info("Unalign bundle: unexp @%llx, %llx\n", (unsigned long long)regs->pc, @@ -1396,11 +1398,12 @@ void jit_bundle_gen(struct pt_regs *regs, tilegx_bundle_bits bundle, &frag, sizeof(frag)); if (status) { /* Fail to copy JIT into user land. send SIGSEGV. */ - siginfo_t info = { - .si_signo = SIGSEGV, - .si_code = SEGV_MAPERR, - .si_addr = (void __user *)&jit_code_area[idx] - }; + siginfo_t info; + + clear_siginfo(&info); + info.si_signo = SIGSEGV; + info.si_code = SEGV_MAPERR; + info.si_addr = (void __user *)&jit_code_area[idx]; pr_warn("Unalign fixup: pid=%d %s jit_code_area=%llx\n", current->pid, current->comm, @@ -1511,11 +1514,12 @@ void do_unaligned(struct pt_regs *regs, int vecnum) * If so, we will trigger SIGBUS. */ if ((regs->sp & 0x7) || (regs->ex1) || (align_ctl < 0)) { - siginfo_t info = { - .si_signo = SIGBUS, - .si_code = BUS_ADRALN, - .si_addr = (unsigned char __user *)0 - }; + siginfo_t info; + + clear_siginfo(&info); + info.si_signo = SIGBUS; + info.si_code = BUS_ADRALN; + info.si_addr = (unsigned char __user *)0; if (unaligned_printk) pr_info("Unalign fixup: %d %llx @%llx\n", @@ -1535,11 +1539,13 @@ void do_unaligned(struct pt_regs *regs, int vecnum) pc = (tilegx_bundle_bits __user *)(regs->pc); if (get_user(bundle, pc) != 0) { /* Probably never be here since pc is valid user address.*/ - siginfo_t info = { - .si_signo = SIGSEGV, - .si_code = SEGV_MAPERR, - .si_addr = (void __user *)pc - }; + siginfo_t info; + + clear_siginfo(&info); + info.si_signo = SIGSEGV; + info.si_code = SEGV_MAPERR; + info.si_addr = (void __user *)pc; + pr_err("Couldn't read instruction at %p trying to step\n", pc); trace_unhandled_signal("segfault in unalign fixup", regs, (unsigned long)info.si_addr, SIGSEGV); diff --git a/kernel/signal.c b/kernel/signal.c index 4976f05aa09b..f14492ff976f 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -3163,8 +3163,9 @@ do_send_specific(pid_t tgid, pid_t pid, int sig, struct siginfo *info) static int do_tkill(pid_t tgid, pid_t pid, int sig) { - struct siginfo info = {}; + struct siginfo info; + clear_siginfo(&info); info.si_signo = sig; info.si_errno = 0; info.si_code = SI_TKILL; -- 2.14.1
