3.2.96-rc1 review patch. If anyone has any objections, please let me know.
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From: Oleg Nesterov oleg@redhat.com
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@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 Signed-off-by: Ben Hutchings ben@decadent.org.uk --- 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) && \