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authorEric W. Biederman <ebiederm@xmission.com>2017-07-31 17:15:31 -0500
committerEric W. Biederman <ebiederm@xmission.com>2018-01-15 17:55:59 -0600
commit212a36a17efe4d696d1e3c31ebd79a9fb0cbb14b (patch)
tree943b3454aad156b37e2396ac314e6afc2d43c84c /kernel/signal.c
parent56b81456f4ee048699f72edc02b369a33d1b94e6 (diff)
downloadlinux-212a36a17efe4d696d1e3c31ebd79a9fb0cbb14b.tar.bz2
signal: Unify and correct copy_siginfo_from_user32
The function copy_siginfo_from_user32 is used for two things, in ptrace since the dawn of siginfo for arbirarily modifying a signal that user space sees, and in sigqueueinfo to send a signal with arbirary siginfo data. Create a single copy of copy_siginfo_from_user32 that all architectures share, and teach it to handle all of the cases in the siginfo union. In the generic version of copy_siginfo_from_user32 ensure that all of the fields in siginfo are initialized so that the siginfo structure can be safely copied to userspace if necessary. When copying the embedded sigval union copy the si_int member. That ensures the 32bit values passes through the kernel unchanged. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Diffstat (limited to 'kernel/signal.c')
-rw-r--r--kernel/signal.c81
1 files changed, 81 insertions, 0 deletions
diff --git a/kernel/signal.c b/kernel/signal.c
index 4c3f4448c5f1..5211b1b57163 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2814,6 +2814,87 @@ int copy_siginfo_to_user(siginfo_t __user *to, const siginfo_t *from)
return err;
}
+#ifdef CONFIG_COMPAT
+int copy_siginfo_from_user32(struct siginfo *to,
+ const struct compat_siginfo __user *ufrom)
+{
+ struct compat_siginfo from;
+
+ if (copy_from_user(&from, ufrom, sizeof(struct compat_siginfo)))
+ return -EFAULT;
+
+ clear_siginfo(to);
+ to->si_signo = from.si_signo;
+ to->si_errno = from.si_errno;
+ to->si_code = from.si_code;
+ switch(siginfo_layout(from.si_signo, from.si_code)) {
+ case SIL_KILL:
+ to->si_pid = from.si_pid;
+ to->si_uid = from.si_uid;
+ break;
+ case SIL_TIMER:
+ to->si_tid = from.si_tid;
+ to->si_overrun = from.si_overrun;
+ to->si_int = from.si_int;
+ break;
+ case SIL_POLL:
+ to->si_band = from.si_band;
+ to->si_fd = from.si_fd;
+ break;
+ case SIL_FAULT:
+ to->si_addr = compat_ptr(from.si_addr);
+#ifdef __ARCH_SI_TRAPNO
+ to->si_trapno = from.si_trapno;
+#endif
+#ifdef BUS_MCEERR_AR
+ if ((from.si_signo == SIGBUS) && (from.si_code == BUS_MCEERR_AR))
+ to->si_addr_lsb = from.si_addr_lsb;
+#endif
+#ifdef BUS_MCEER_AO
+ if ((from.si_signo == SIGBUS) && (from.si_code == BUS_MCEERR_AO))
+ to->si_addr_lsb = from.si_addr_lsb;
+#endif
+#ifdef SEGV_BNDERR
+ if ((from.si_signo == SIGSEGV) && (from.si_code == SEGV_BNDERR)) {
+ to->si_lower = compat_ptr(from.si_lower);
+ to->si_upper = compat_ptr(from.si_upper);
+ }
+#endif
+#ifdef SEGV_PKUERR
+ if ((from.si_signo == SIGSEGV) && (from.si_code == SEGV_PKUERR))
+ to->si_pkey = from.si_pkey;
+#endif
+ break;
+ case SIL_CHLD:
+ to->si_pid = from.si_pid;
+ to->si_uid = from.si_uid;
+ to->si_status = from.si_status;
+#ifdef CONFIG_X86_X32_ABI
+ if (in_x32_syscall()) {
+ to->si_utime = from._sifields._sigchld_x32._utime;
+ to->si_stime = from._sifields._sigchld_x32._stime;
+ } else
+#endif
+ {
+ to->si_utime = from.si_utime;
+ to->si_stime = from.si_stime;
+ }
+ break;
+ case SIL_RT:
+ to->si_pid = from.si_pid;
+ to->si_uid = from.si_uid;
+ to->si_int = from.si_int;
+ break;
+ case SIL_SYS:
+ to->si_call_addr = compat_ptr(from.si_call_addr);
+ to->si_syscall = from.si_syscall;
+ to->si_arch = from.si_arch;
+ break;
+ }
+ return 0;
+}
+#endif /* CONFIG_COMPAT */
+
/**
* do_sigtimedwait - wait for queued signals specified in @which
* @which: queued signals to wait for