Dmitry Vyukov <dvyukov@xxxxxxxxxx> wrote: [ CC nf-devel, not sure if its nfnetlink fault or NETLINK_MMAP ] > The following program causes GPF in netlink_getsockbyportid: > > // autogenerated by syzkaller (http://github.com/google/syzkaller) > #include <pthread.h> > #include <stdint.h> > #include <string.h> > #include <sys/syscall.h> > #include <unistd.h> > > int main() > { > syscall(SYS_mmap, 0x20000000ul, 0xe65000ul, 0x3ul, 0x32ul, > 0xfffffffffffffffful, 0x0ul); > int fd = syscall(SYS_socket, 0x10ul, 0x803ul, 0xcul, 0, 0, 0); > *(uint32_t*)0x20e64000 = (uint32_t)0x28; > *(uint32_t*)0x20e64004 = (uint32_t)0x10; > *(uint64_t*)0x20e64008 = (uint64_t)0x0; > *(uint64_t*)0x20e64010 = (uint64_t)0x3; > *(uint64_t*)0x20e64018 = (uint64_t)0xfff; > *(uint16_t*)0x20e64020 = (uint16_t)0x5; > syscall(SYS_write, fd, 0x20e64000ul, 0x28ul, 0, 0, 0); > return 0; > } CONFIG_NETLINK_MMAP and nfnetlink batching strike in unison :-/ root cause is in nfnetlink_rcv_batch(): 296 replay: 297 status = 0; 298 299 skb = netlink_skb_clone(oskb, GFP_KERNEL); The clone op doesn't copy oskb->sk, so we oops in __netlink_alloc_skb -> netlink_getsockbyportid() when nfnetlink_rcv_batch tries to send netlink ack. -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
