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authorEric W. Biederman <ebiederm@xmission.com>2018-04-17 15:26:37 -0500
committerEric W. Biederman <ebiederm@xmission.com>2018-04-25 10:40:51 -0500
commit3eb0f5193b497083391aa05d35210d5645211eef (patch)
tree65f009d4cdd5e407741a4431c0aacd40452779bd /arch/arm/kernel
parentf6ed1ecad56fec7ab5c6bf741064b95801e9688f (diff)
signal: Ensure every siginfo we send has all bits initialized
Call clear_siginfo to ensure every stack allocated siginfo is properly initialized before being passed to the signal sending functions. Note: It is not safe to depend on C initializers to initialize struct siginfo on the stack because C is allowed to skip holes when initializing a structure. The initialization of struct siginfo in tracehook_report_syscall_exit was moved from the helper user_single_step_siginfo into tracehook_report_syscall_exit itself, to make it clear that the local variable siginfo gets fully initialized. In a few cases the scope of struct siginfo has been reduced to make it clear that siginfo siginfo is not used on other paths in the function in which it is declared. Instances of using memset to initialize siginfo have been replaced with calls clear_siginfo for clarity. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Diffstat (limited to 'arch/arm/kernel')
-rw-r--r--arch/arm/kernel/ptrace.c1
-rw-r--r--arch/arm/kernel/swp_emulate.c1
-rw-r--r--arch/arm/kernel/traps.c5
3 files changed, 7 insertions, 0 deletions
diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c
index 7724b0f661b3..36718a424358 100644
--- a/arch/arm/kernel/ptrace.c
+++ b/arch/arm/kernel/ptrace.c
@@ -205,6 +205,7 @@ void ptrace_break(struct task_struct *tsk, struct pt_regs *regs)
{
siginfo_t info;
+ clear_siginfo(&info);
info.si_signo = SIGTRAP;
info.si_errno = 0;
info.si_code = TRAP_BRKPT;
diff --git a/arch/arm/kernel/swp_emulate.c b/arch/arm/kernel/swp_emulate.c
index 3bda08bee674..dfcb456afadd 100644
--- a/arch/arm/kernel/swp_emulate.c
+++ b/arch/arm/kernel/swp_emulate.c
@@ -112,6 +112,7 @@ static void set_segfault(struct pt_regs *regs, unsigned long addr)
{
siginfo_t info;
+ clear_siginfo(&info);
down_read(&current->mm->mmap_sem);
if (find_vma(current->mm, addr) == NULL)
info.si_code = SEGV_MAPERR;
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 5e3633c24e63..2584f9066da3 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -439,6 +439,7 @@ asmlinkage void do_undefinstr(struct pt_regs *regs)
siginfo_t info;
void __user *pc;
+ clear_siginfo(&info);
pc = (void __user *)instruction_pointer(regs);
if (processor_mode(regs) == SVC_MODE) {
@@ -537,6 +538,7 @@ static int bad_syscall(int n, struct pt_regs *regs)
{
siginfo_t info;
+ clear_siginfo(&info);
if ((current->personality & PER_MASK) != PER_LINUX) {
send_sig(SIGSEGV, current, 1);
return regs->ARM_r0;
@@ -604,6 +606,7 @@ asmlinkage int arm_syscall(int no, struct pt_regs *regs)
{
siginfo_t info;
+ clear_siginfo(&info);
if ((no >> 16) != (__ARM_NR_BASE>> 16))
return bad_syscall(no, regs);
@@ -740,6 +743,8 @@ baddataabort(int code, unsigned long instr, struct pt_regs *regs)
unsigned long addr = instruction_pointer(regs);
siginfo_t info;
+ clear_siginfo(&info);
+
#ifdef CONFIG_DEBUG_USER
if (user_debug & UDBG_BADABORT) {
pr_err("[%d] %s: bad data abort: code %d instr 0x%08lx\n",