Started in network mode Own node identity e0000002, cluster identity 4711 New replicast peer: 172.20.20.187 netlink: 20 bytes leftover after parsing attributes in process `syz-executor5'. ================================================================== BUG: KASAN: use-after-free in atomic_read include/asm-generic/atomic-instrumented.h:21 [inline] BUG: KASAN: use-after-free in refcount_read include/linux/refcount.h:43 [inline] BUG: KASAN: use-after-free in skb_unref include/linux/skbuff.h:980 [inline] BUG: KASAN: use-after-free in kfree_skb+0xb7/0x580 net/core/skbuff.c:655 Read of size 4 at addr ffff8881c423a0e4 by task syz-executor0/12850 CPU: 0 PID: 12850 Comm: syz-executor0 Not tainted 4.20.0-rc6+ #342 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x244/0x39d lib/dump_stack.c:113 print_address_description.cold.7+0x9/0x1ff mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.8+0x242/0x309 mm/kasan/report.c:412 check_memory_region_inline mm/kasan/kasan.c:260 [inline] check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267 kasan_check_read+0x11/0x20 mm/kasan/kasan.c:272 atomic_read include/asm-generic/atomic-instrumented.h:21 [inline] refcount_read include/linux/refcount.h:43 [inline] skb_unref include/linux/skbuff.h:980 [inline] kfree_skb+0xb7/0x580 net/core/skbuff.c:655 tipc_udp_send_msg+0x5af/0x680 net/tipc/udp_media.c:249 tipc_bearer_xmit_skb+0x171/0x350 net/tipc/bearer.c:502 tipc_enable_bearer+0xc5e/0xf10 net/tipc/bearer.c:327 __tipc_nl_bearer_enable+0x37c/0x4a0 net/tipc/bearer.c:897 tipc_nl_bearer_enable+0x22/0x30 net/tipc/bearer.c:905 genl_family_rcv_msg+0x8a7/0x11a0 net/netlink/genetlink.c:601 genl_rcv_msg+0xc6/0x168 net/netlink/genetlink.c:626 netlink_rcv_skb+0x172/0x440 net/netlink/af_netlink.c:2477 genl_rcv+0x28/0x40 net/netlink/genetlink.c:637 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline] netlink_unicast+0x5a5/0x760 net/netlink/af_netlink.c:1336 netlink_sendmsg+0xa18/0xfc0 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:631 ___sys_sendmsg+0x7fd/0x930 net/socket.c:2116 __sys_sendmsg+0x11d/0x280 net/socket.c:2154 __do_sys_sendmsg net/socket.c:2163 [inline] __se_sys_sendmsg net/socket.c:2161 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2161 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457679 Code: fd b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fe805de4c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457679 RDX: 0000000000000010 RSI: 00000000200003c0 RDI: 0000000000000003 RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe805de56d4 R13: 00000000004c423b R14: 00000000004d7180 R15: 00000000ffffffff Allocated by task 12850: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490 kmem_cache_alloc_node+0x144/0x730 mm/slab.c:3644 __alloc_skb+0x119/0x770 net/core/skbuff.c:193 __pskb_copy_fclone+0x16b/0xeb0 net/core/skbuff.c:1392 __pskb_copy include/linux/skbuff.h:1064 [inline] pskb_copy include/linux/skbuff.h:2926 [inline] tipc_udp_send_msg+0x457/0x680 net/tipc/udp_media.c:241 tipc_bearer_xmit_skb+0x171/0x350 net/tipc/bearer.c:502 tipc_enable_bearer+0xc5e/0xf10 net/tipc/bearer.c:327 __tipc_nl_bearer_enable+0x37c/0x4a0 net/tipc/bearer.c:897 tipc_nl_bearer_enable+0x22/0x30 net/tipc/bearer.c:905 genl_family_rcv_msg+0x8a7/0x11a0 net/netlink/genetlink.c:601 genl_rcv_msg+0xc6/0x168 net/netlink/genetlink.c:626 netlink_rcv_skb+0x172/0x440 net/netlink/af_netlink.c:2477 genl_rcv+0x28/0x40 net/netlink/genetlink.c:637 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline] netlink_unicast+0x5a5/0x760 net/netlink/af_netlink.c:1336 netlink_sendmsg+0xa18/0xfc0 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:631 ___sys_sendmsg+0x7fd/0x930 net/socket.c:2116 __sys_sendmsg+0x11d/0x280 net/socket.c:2154 __do_sys_sendmsg net/socket.c:2163 [inline] __se_sys_sendmsg net/socket.c:2161 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2161 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 12850: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kmem_cache_free+0x83/0x290 mm/slab.c:3760 kfree_skbmem+0x154/0x230 net/core/skbuff.c:582 __kfree_skb net/core/skbuff.c:642 [inline] kfree_skb+0x1c3/0x580 net/core/skbuff.c:659 tipc_udp_xmit.isra.14+0x41e/0xee0 net/tipc/udp_media.c:207 tipc_udp_send_msg+0x3a1/0x680 net/tipc/udp_media.c:247 tipc_bearer_xmit_skb+0x171/0x350 net/tipc/bearer.c:502 tipc_enable_bearer+0xc5e/0xf10 net/tipc/bearer.c:327 __tipc_nl_bearer_enable+0x37c/0x4a0 net/tipc/bearer.c:897 tipc_nl_bearer_enable+0x22/0x30 net/tipc/bearer.c:905 genl_family_rcv_msg+0x8a7/0x11a0 net/netlink/genetlink.c:601 genl_rcv_msg+0xc6/0x168 net/netlink/genetlink.c:626 netlink_rcv_skb+0x172/0x440 net/netlink/af_netlink.c:2477 genl_rcv+0x28/0x40 net/netlink/genetlink.c:637 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline] netlink_unicast+0x5a5/0x760 net/netlink/af_netlink.c:1336 netlink_sendmsg+0xa18/0xfc0 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:631 ___sys_sendmsg+0x7fd/0x930 net/socket.c:2116 __sys_sendmsg+0x11d/0x280 net/socket.c:2154 __do_sys_sendmsg net/socket.c:2163 [inline] __se_sys_sendmsg net/socket.c:2161 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2161 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8881c423a000 which belongs to the cache skbuff_head_cache of size 232 The buggy address is located 228 bytes inside of 232-byte region [ffff8881c423a000, ffff8881c423a0e8) The buggy address belongs to the page: page:ffffea0007108e80 count:1 mapcount:0 mapping:ffff8881d9bee600 index:0x0 flags: 0x2fffc0000000200(slab) raw: 02fffc0000000200 ffffea0007394ac8 ffffea0007112548 ffff8881d9bee600 raw: 0000000000000000 ffff8881c423a000 000000010000000c 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8881c4239f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8881c423a000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8881c423a080: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc ^ ffff8881c423a100: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ffff8881c423a180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ================================================================== ------------[ cut here ]------------ BUG: KASAN: double-free or invalid-free in skb_free_head+0x99/0xc0 net/core/skbuff.c:550 downgrading a read lock WARNING: CPU: 1 PID: 12863 at kernel/locking/lockdep.c:3556 __lock_downgrade kernel/locking/lockdep.c:3556 [inline] WARNING: CPU: 1 PID: 12863 at kernel/locking/lockdep.c:3556 lock_downgrade+0x4d7/0x900 kernel/locking/lockdep.c:3819