diff options
| author | Eric W. Biederman <ebiederm@xmission.com> | 2018-01-05 17:27:42 -0600 |
|---|---|---|
| committer | Eric W. Biederman <ebiederm@xmission.com> | 2018-01-12 14:21:07 -0600 |
| commit | faf1f22b61f2715224ba9b579e2a983e99b86823 (patch) | |
| tree | fb871c31027141a61c4e1d898d967df6baab025d /kernel/signal.c | |
| parent | 8c5dbf2ae00bb8667f61c5edc6521c1fa2bbe4d7 (diff) | |
signal: Ensure generic siginfos the kernel sends have all bits initialized
Call clear_siginfo to ensure stack allocated siginfos are fully
initialized before being passed to the signal sending functions.
This ensures that if there is the kind of confusion documented by
TRAP_FIXME, FPE_FIXME, or BUS_FIXME the kernel won't send unitialized
data to userspace when the kernel generates a signal with SI_USER but
the copy to userspace assumes it is a different kind of signal, and
different fields are initialized.
This also prepares the way for turning copy_siginfo_to_user
into a copy_to_user, by removing the need in many cases to perform
a field by field copy simply to skip the uninitialized fields.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Diffstat (limited to 'kernel/signal.c')
| -rw-r--r-- | kernel/signal.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/kernel/signal.c b/kernel/signal.c index fd182a845490..241d54958bbb 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -549,6 +549,7 @@ still_pending: * a fast-pathed signal or we must have been * out of queue space. So zero out the info. */ + clear_siginfo(info); info->si_signo = sig; info->si_errno = 0; info->si_code = SI_USER; @@ -1043,6 +1044,7 @@ static int __send_signal(int sig, struct siginfo *info, struct task_struct *t, list_add_tail(&q->list, &pending->list); switch ((unsigned long) info) { case (unsigned long) SEND_SIG_NOINFO: + clear_siginfo(&q->info); q->info.si_signo = sig; q->info.si_errno = 0; q->info.si_code = SI_USER; @@ -1051,6 +1053,7 @@ static int __send_signal(int sig, struct siginfo *info, struct task_struct *t, q->info.si_uid = from_kuid_munged(current_user_ns(), current_uid()); break; case (unsigned long) SEND_SIG_PRIV: + clear_siginfo(&q->info); q->info.si_signo = sig; q->info.si_errno = 0; q->info.si_code = SI_KERNEL; @@ -1623,6 +1626,7 @@ bool do_notify_parent(struct task_struct *tsk, int sig) sig = SIGCHLD; } + clear_siginfo(&info); info.si_signo = sig; info.si_errno = 0; /* @@ -1717,6 +1721,7 @@ static void do_notify_parent_cldstop(struct task_struct *tsk, parent = tsk->real_parent; } + clear_siginfo(&info); info.si_signo = SIGCHLD; info.si_errno = 0; /* @@ -1929,7 +1934,7 @@ static void ptrace_do_notify(int signr, int exit_code, int why) { siginfo_t info; - memset(&info, 0, sizeof info); + clear_siginfo(&info); info.si_signo = signr; info.si_code = exit_code; info.si_pid = task_pid_vnr(current); @@ -2136,6 +2141,7 @@ static int ptrace_signal(int signr, siginfo_t *info) * have updated *info via PTRACE_SETSIGINFO. */ if (signr != info->si_signo) { + clear_siginfo(info); info->si_signo = signr; info->si_errno = 0; info->si_code = SI_USER; @@ -2941,6 +2947,7 @@ SYSCALL_DEFINE2(kill, pid_t, pid, int, sig) { struct siginfo info; + clear_siginfo(&info); info.si_signo = sig; info.si_errno = 0; info.si_code = SI_USER; |