From: Xin Long <lucien.xin@xxxxxxxxx> Date: Sun, 31 Mar 2019 16:58:15 +0800 > Syzbot report a kernel-infoleak: > > BUG: KMSAN: kernel-infoleak in _copy_to_user+0x16b/0x1f0 lib/usercopy.c:32 > Call Trace: > _copy_to_user+0x16b/0x1f0 lib/usercopy.c:32 > copy_to_user include/linux/uaccess.h:174 [inline] > sctp_getsockopt_peer_addrs net/sctp/socket.c:5911 [inline] > sctp_getsockopt+0x1668e/0x17f70 net/sctp/socket.c:7562 > ... > Uninit was stored to memory at: > sctp_transport_init net/sctp/transport.c:61 [inline] > sctp_transport_new+0x16d/0x9a0 net/sctp/transport.c:115 > sctp_assoc_add_peer+0x532/0x1f70 net/sctp/associola.c:637 > sctp_process_param net/sctp/sm_make_chunk.c:2548 [inline] > sctp_process_init+0x1a1b/0x3ed0 net/sctp/sm_make_chunk.c:2361 > ... > Bytes 8-15 of 16 are uninitialized > > It was caused by that th _pad field (the 8-15 bytes) of a v4 addr (saved in > struct sockaddr_in) wasn't initialized, but directly copied to user memory > in sctp_getsockopt_peer_addrs(). > > So fix it by calling memset(addr->v4.sin_zero, 0, 8) to initialize _pad of > sockaddr_in before copying it to user memory in sctp_v4_addr_to_user(), as > sctp_v6_addr_to_user() does. > > Reported-by: syzbot+86b5c7c236a22616a72f@xxxxxxxxxxxxxxxxxxxxxxxxx > Signed-off-by: Xin Long <lucien.xin@xxxxxxxxx> Applied and queued up for -stable, thanks Xin!
