3.2.96-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Oleg Nesterov <oleg@xxxxxxxxxx> commit 5c8ccefdf46c5f87d87b694c7fbc04941c2c99a5 upstream. 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@xxxxxxxxxx Reported-by: Meelis Roos <mroos@xxxxxxxx> Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx> --- include/linux/signal.h | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) --- a/include/linux/signal.h +++ b/include/linux/signal.h @@ -345,7 +345,9 @@ int unhandled_signal(struct task_struct #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)) @@ -366,14 +368,10 @@ int unhandled_signal(struct task_struct 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) && \