signal: move the "sig < SIGRTMIN" check into siginmask(sig)

All the users of siginmask() must ensure that sig < SIGRTMIN.  sig_fatal()
doesn't and this is wrong:

	UBSAN: Undefined behaviour in kernel/signal.c:911:6
	shift exponent 32 is too large for 32-bit type 'long unsigned int'

the patch doesn't add the neccesary check to sig_fatal(), it moves the
check into siginmask() and updates other callers.

Link: http://lkml.kernel.org/r/20160517195052.GA15187@redhat.com
Reported-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Oleg Nesterov 2016-05-23 16:24:02 -07:00 committed by Linus Torvalds
parent 747800efbe
commit 5c8ccefdf4

View file

@ -400,7 +400,9 @@ int unhandled_signal(struct task_struct *tsk, int sig);
#else
#define rt_sigmask(sig) sigmask(sig)
#endif
#define siginmask(sig, mask) (rt_sigmask(sig) & (mask))
#define siginmask(sig, mask) \
((sig) < SIGRTMIN && (rt_sigmask(sig) & (mask)))
#define SIG_KERNEL_ONLY_MASK (\
rt_sigmask(SIGKILL) | rt_sigmask(SIGSTOP))
@ -421,14 +423,10 @@ int unhandled_signal(struct task_struct *tsk, int sig);
rt_sigmask(SIGCONT) | rt_sigmask(SIGCHLD) | \
rt_sigmask(SIGWINCH) | rt_sigmask(SIGURG) )
#define sig_kernel_only(sig) \
(((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_ONLY_MASK))
#define sig_kernel_coredump(sig) \
(((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_COREDUMP_MASK))
#define sig_kernel_ignore(sig) \
(((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_IGNORE_MASK))
#define sig_kernel_stop(sig) \
(((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_STOP_MASK))
#define sig_kernel_only(sig) siginmask(sig, SIG_KERNEL_ONLY_MASK)
#define sig_kernel_coredump(sig) siginmask(sig, SIG_KERNEL_COREDUMP_MASK)
#define sig_kernel_ignore(sig) siginmask(sig, SIG_KERNEL_IGNORE_MASK)
#define sig_kernel_stop(sig) siginmask(sig, SIG_KERNEL_STOP_MASK)
#define sig_user_defined(t, signr) \
(((t)->sighand->action[(signr)-1].sa.sa_handler != SIG_DFL) && \