===================================================== BUG: KMSAN: kernel-infoleak in kmsan_copy_to_user+0x9c/0xb0 syzkaller/managers/upstream-kmsan-gce/kernel/mm/kmsan/kmsan_hooks.c:249 CPU: 1 PID: 8484 Comm: syz-executor306 Not tainted 5.10.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack syzkaller/managers/upstream-kmsan-gce/kernel/lib/dump_stack.c:77 [inline] dump_stack+0x21c/0x280 syzkaller/managers/upstream-kmsan-gce/kernel/lib/dump_stack.c:118 kmsan_report+0xfb/0x1e0 syzkaller/managers/upstream-kmsan-gce/kernel/mm/kmsan/kmsan_report.c:118 kmsan_internal_check_memory+0x202/0x520 syzkaller/managers/upstream-kmsan-gce/kernel/mm/kmsan/kmsan.c:402 kmsan_copy_to_user+0x9c/0xb0 syzkaller/managers/upstream-kmsan-gce/kernel/mm/kmsan/kmsan_hooks.c:249 instrument_copy_to_user syzkaller/managers/upstream-kmsan-gce/kernel/./include/linux/instrumented.h:121 [inline] copyout syzkaller/managers/upstream-kmsan-gce/kernel/lib/iov_iter.c:147 [inline] _copy_to_iter+0x637/0x2ed0 syzkaller/managers/upstream-kmsan-gce/kernel/lib/iov_iter.c:638 copy_to_iter syzkaller/managers/upstream-kmsan-gce/kernel/./include/linux/uio.h:137 [inline] simple_copy_to_iter+0xf6/0x150 syzkaller/managers/upstream-kmsan-gce/kernel/net/core/datagram.c:519 __skb_datagram_iter+0x2cb/0x1210 syzkaller/managers/upstream-kmsan-gce/kernel/net/core/datagram.c:425 skb_copy_datagram_iter+0xd8/0x200 syzkaller/managers/upstream-kmsan-gce/kernel/net/core/datagram.c:533 skb_copy_datagram_msg syzkaller/managers/upstream-kmsan-gce/kernel/./include/linux/skbuff.h:3532 [inline] packet_recvmsg+0x764/0x2060 syzkaller/managers/upstream-kmsan-gce/kernel/net/packet/af_packet.c:3391 ____sys_recvmsg+0x57f/0xd50 syzkaller/managers/upstream-kmsan-gce/kernel/net/socket.c:885 ___sys_recvmsg syzkaller/managers/upstream-kmsan-gce/kernel/net/socket.c:2618 [inline] do_recvmmsg+0xaa7/0x22f0 syzkaller/managers/upstream-kmsan-gce/kernel/net/socket.c:2718 __sys_recvmmsg syzkaller/managers/upstream-kmsan-gce/kernel/net/socket.c:2797 [inline] __do_sys_recvmmsg syzkaller/managers/upstream-kmsan-gce/kernel/net/socket.c:2820 [inline] __se_sys_recvmmsg+0x24a/0x410 syzkaller/managers/upstream-kmsan-gce/kernel/net/socket.c:2813 __x64_sys_recvmmsg+0x62/0x80 syzkaller/managers/upstream-kmsan-gce/kernel/net/socket.c:2813 do_syscall_64+0x9f/0x140 syzkaller/managers/upstream-kmsan-gce/kernel/arch/x86/entry/common.c:48 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x443789 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 41 15 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffcf2b89a68 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000443789 RDX: 0000000000000001 RSI: 0000000020001500 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 000000000000000d R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffcf2b89a80 R13: 00000000000f4240 R14: 0000000000023ea9 R15: 00007ffcf2b89a74 Uninit was stored to memory at: kmsan_save_stack_with_flags syzkaller/managers/upstream-kmsan-gce/kernel/mm/kmsan/kmsan.c:121 [inline] kmsan_internal_chain_origin+0xad/0x130 syzkaller/managers/upstream-kmsan-gce/kernel/mm/kmsan/kmsan.c:289 kmsan_memcpy_memmove_metadata+0x25e/0x2d0 syzkaller/managers/upstream-kmsan-gce/kernel/mm/kmsan/kmsan.c:226 kmsan_memcpy_metadata+0xb/0x10 syzkaller/managers/upstream-kmsan-gce/kernel/mm/kmsan/kmsan.c:246 __msan_memcpy+0x46/0x60 syzkaller/managers/upstream-kmsan-gce/kernel/mm/kmsan/kmsan_instr.c:110 pskb_expand_head+0x3d6/0x1e20 syzkaller/managers/upstream-kmsan-gce/kernel/net/core/skbuff.c:1631 __skb_cow syzkaller/managers/upstream-kmsan-gce/kernel/./include/linux/skbuff.h:3165 [inline] skb_cow_head syzkaller/managers/upstream-kmsan-gce/kernel/./include/linux/skbuff.h:3199 [inline] batadv_skb_head_push+0x2cc/0x410 syzkaller/managers/upstream-kmsan-gce/kernel/net/batman-adv/soft-interface.c:75 batadv_send_skb_packet+0x1ed/0x970 syzkaller/managers/upstream-kmsan-gce/kernel/net/batman-adv/send.c:86 batadv_send_broadcast_skb+0x76/0x90 syzkaller/managers/upstream-kmsan-gce/kernel/net/batman-adv/send.c:127 batadv_iv_ogm_send_to_if syzkaller/managers/upstream-kmsan-gce/kernel/net/batman-adv/bat_iv_ogm.c:394 [inline] batadv_iv_ogm_emit syzkaller/managers/upstream-kmsan-gce/kernel/net/batman-adv/bat_iv_ogm.c:420 [inline] batadv_iv_send_outstanding_bat_ogm_packet+0xb2d/0xef0 syzkaller/managers/upstream-kmsan-gce/kernel/net/batman-adv/bat_iv_ogm.c:1712 process_one_work+0x1219/0x1fe0 syzkaller/managers/upstream-kmsan-gce/kernel/kernel/workqueue.c:2272 worker_thread+0x123c/0x2730 syzkaller/managers/upstream-kmsan-gce/kernel/kernel/workqueue.c:2418 kthread+0x51c/0x560 syzkaller/managers/upstream-kmsan-gce/kernel/kernel/kthread.c:292 ret_from_fork+0x1f/0x30 syzkaller/managers/upstream-kmsan-gce/kernel/arch/x86/entry/entry_64.S:296 Uninit was created at: kmsan_save_stack_with_flags+0x3c/0x90 syzkaller/managers/upstream-kmsan-gce/kernel/mm/kmsan/kmsan.c:121 kmsan_alloc_page+0xd3/0x1f0 syzkaller/managers/upstream-kmsan-gce/kernel/mm/kmsan/kmsan_shadow.c:274 __alloc_pages_nodemask+0x827/0xf90 syzkaller/managers/upstream-kmsan-gce/kernel/mm/page_alloc.c:4989 __alloc_pages syzkaller/managers/upstream-kmsan-gce/kernel/./include/linux/gfp.h:511 [inline] __alloc_pages_node syzkaller/managers/upstream-kmsan-gce/kernel/./include/linux/gfp.h:524 [inline] alloc_pages_node syzkaller/managers/upstream-kmsan-gce/kernel/./include/linux/gfp.h:538 [inline] __page_frag_cache_refill syzkaller/managers/upstream-kmsan-gce/kernel/mm/page_alloc.c:5065 [inline] page_frag_alloc+0x357/0x890 syzkaller/managers/upstream-kmsan-gce/kernel/mm/page_alloc.c:5095 __napi_alloc_skb+0x1bf/0xaa0 syzkaller/managers/upstream-kmsan-gce/kernel/net/core/skbuff.c:519 napi_alloc_skb syzkaller/managers/upstream-kmsan-gce/kernel/./include/linux/skbuff.h:2870 [inline] page_to_skb+0x142/0x1640 syzkaller/managers/upstream-kmsan-gce/kernel/drivers/net/virtio_net.c:389 receive_mergeable+0xef5/0x5bb0 syzkaller/managers/upstream-kmsan-gce/kernel/drivers/net/virtio_net.c:949 receive_buf+0x2dc/0x2bb0 syzkaller/managers/upstream-kmsan-gce/kernel/drivers/net/virtio_net.c:1059 virtnet_receive syzkaller/managers/upstream-kmsan-gce/kernel/drivers/net/virtio_net.c:1351 [inline] virtnet_poll+0xa51/0x1d10 syzkaller/managers/upstream-kmsan-gce/kernel/drivers/net/virtio_net.c:1456 napi_poll+0x40a/0x1020 syzkaller/managers/upstream-kmsan-gce/kernel/net/core/dev.c:6763 net_rx_action+0x34c/0xd30 syzkaller/managers/upstream-kmsan-gce/kernel/net/core/dev.c:6833 __do_softirq+0x1a9/0x6fa syzkaller/managers/upstream-kmsan-gce/kernel/kernel/softirq.c:298 Bytes 52-53 of 146 are uninitialized Memory access of size 146 starts at ffff88812ecb1c40 Data copied to user address 00000000200001c0 =====================================================