Commit 5c8ccefd authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Linus Torvalds
Browse files

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: default avatarMeelis Roos <mroos@linux.ee>
Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 747800ef

include/linux/signal.h

+7 −9
Original line number Diff line number Diff line
@@ -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) &&	\

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