Hello, syzbot found the following issue on: HEAD commit: ae085d7f9365 mm: kfence: fix missing objcg housekeeping fo.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=17656105700000 kernel config: https://syzkaller.appspot.com/x/.config?x=6bae4cd50262530e dashboard link: https://syzkaller.appspot.com/bug?extid=a9dce1ff45c3bbeceb3a compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12529653700000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14b64ea5700000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+a9dce1ff45c3bbeceb3a@xxxxxxxxxxxxxxxxxxxxxxxxx vcan0: j1939_xtp_rx_dat_one: 0xffff88801fe31400: last 00 vcan0: j1939_xtp_rx_dat_one: 0xffff88801fe31800: last 00 vcan0: j1939_xtp_rx_dat_one: 0xffff88801fe31800: Data of RX-looped back packet (00 ff ff ff ff ff ff) doesn't match TX data (00 00 00 00 00 00 00)! ================================================================== BUG: KASAN: use-after-free in j1939_xtp_rx_dat_one+0xe15/0xee0 net/can/j1939/transport.c:1877 Read of size 1 at addr ffff88802304ab8e by task ksoftirqd/1/21 CPU: 1 PID: 21 Comm: ksoftirqd/1 Tainted: G W 5.17.0-syzkaller-11407-gae085d7f9365 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0xeb/0x495 mm/kasan/report.c:313 print_report mm/kasan/report.c:429 [inline] kasan_report.cold+0xf4/0x1c6 mm/kasan/report.c:491 j1939_xtp_rx_dat_one+0xe15/0xee0 net/can/j1939/transport.c:1877 j1939_xtp_rx_dat net/can/j1939/transport.c:1929 [inline] j1939_tp_recv+0x6de/0xcb0 net/can/j1939/transport.c:2123 j1939_can_recv+0x6ff/0x9a0 net/can/j1939/main.c:108 deliver net/can/af_can.c:574 [inline] can_rcv_filter+0x5d4/0x8d0 net/can/af_can.c:608 can_receive+0x31d/0x580 net/can/af_can.c:665 can_rcv+0x120/0x1c0 net/can/af_can.c:696 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5405 __netif_receive_skb+0x24/0x1b0 net/core/dev.c:5519 process_backlog+0x3a0/0x7c0 net/core/dev.c:5847 __napi_poll+0xb3/0x6e0 net/core/dev.c:6413 napi_poll net/core/dev.c:6480 [inline] net_rx_action+0x8ec/0xc60 net/core/dev.c:6567 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 run_ksoftirqd kernel/softirq.c:921 [inline] run_ksoftirqd+0x2d/0x60 kernel/softirq.c:913 smpboot_thread_fn+0x645/0x9c0 kernel/smpboot.c:164 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 </TASK> Allocated by task 3606: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:436 [inline] __kasan_slab_alloc+0x90/0xc0 mm/kasan/common.c:469 kasan_slab_alloc include/linux/kasan.h:224 [inline] slab_post_alloc_hook mm/slab.h:749 [inline] slab_alloc_node mm/slub.c:3217 [inline] kmem_cache_alloc_node+0x255/0x3f0 mm/slub.c:3267 __alloc_skb+0x215/0x340 net/core/skbuff.c:414 alloc_skb include/linux/skbuff.h:1300 [inline] alloc_skb_with_frags+0x93/0x730 net/core/skbuff.c:5988 sock_alloc_send_pskb+0x793/0x920 net/core/sock.c:2600 j1939_sk_alloc_skb net/can/j1939/socket.c:861 [inline] j1939_sk_send_loop net/can/j1939/socket.c:1118 [inline] j1939_sk_sendmsg+0x6eb/0x13f0 net/can/j1939/socket.c:1253 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:725 sock_no_sendpage+0xf6/0x140 net/core/sock.c:3106 kernel_sendpage.part.0+0x1ff/0x7b0 net/socket.c:3492 kernel_sendpage net/socket.c:3489 [inline] sock_sendpage+0xdf/0x140 net/socket.c:1007 pipe_to_sendpage+0x2ad/0x380 fs/splice.c:364 splice_from_pipe_feed fs/splice.c:418 [inline] __splice_from_pipe+0x43e/0x8a0 fs/splice.c:562 splice_from_pipe fs/splice.c:597 [inline] generic_splice_sendpage+0xd4/0x140 fs/splice.c:746 do_splice_from fs/splice.c:767 [inline] direct_splice_actor+0x110/0x180 fs/splice.c:936 splice_direct_to_actor+0x34b/0x8c0 fs/splice.c:891 do_splice_direct+0x1a7/0x270 fs/splice.c:979 do_sendfile+0xae0/0x1240 fs/read_write.c:1246 __do_sys_sendfile64 fs/read_write.c:1311 [inline] __se_sys_sendfile64 fs/read_write.c:1297 [inline] __x64_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1297 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0x80 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Freed by task 15: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track+0x21/0x30 mm/kasan/common.c:45 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free+0x166/0x1a0 mm/kasan/common.c:328 kasan_slab_free include/linux/kasan.h:200 [inline] slab_free_hook mm/slub.c:1728 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1754 slab_free mm/slub.c:3510 [inline] kmem_cache_free+0xdd/0x5a0 mm/slub.c:3527 kfree_skbmem+0xef/0x1b0 net/core/skbuff.c:700 kfree_skb_reason+0x85/0x110 include/linux/refcount.h:279 kfree_skb include/linux/skbuff.h:1250 [inline] j1939_session_skb_drop_old net/can/j1939/transport.c:340 [inline] j1939_xtp_rx_cts_one net/can/j1939/transport.c:1434 [inline] j1939_xtp_rx_cts+0xbdb/0x1170 net/can/j1939/transport.c:1473 j1939_tp_cmd_recv net/can/j1939/transport.c:2061 [inline] j1939_tp_recv+0x83c/0xcb0 net/can/j1939/transport.c:2133 j1939_can_recv+0x6ff/0x9a0 net/can/j1939/main.c:108 deliver net/can/af_can.c:574 [inline] can_rcv_filter+0x5d4/0x8d0 net/can/af_can.c:608 can_receive+0x31d/0x580 net/can/af_can.c:665 can_rcv+0x120/0x1c0 net/can/af_can.c:696 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5405 __netif_receive_skb+0x24/0x1b0 net/core/dev.c:5519 process_backlog+0x3a0/0x7c0 net/core/dev.c:5847 __napi_poll+0xb3/0x6e0 net/core/dev.c:6413 napi_poll net/core/dev.c:6480 [inline] net_rx_action+0x8ec/0xc60 net/core/dev.c:6567 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 The buggy address belongs to the object at ffff88802304ab40 which belongs to the cache skbuff_head_cache of size 232 The buggy address is located 78 bytes inside of 232-byte region [ffff88802304ab40, ffff88802304ac28) The buggy address belongs to the physical page: page:ffffea00008c1280 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2304a flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 0000000000000000 dead000000000122 ffff888140b8d500 raw: 0000000000000000 00000000000c000c 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY), pid 3590, tgid 3590 (kworker/1:3), ts 33637485571, free_ts 33296379898 prep_new_page mm/page_alloc.c:2438 [inline] get_page_from_freelist+0xba2/0x3df0 mm/page_alloc.c:4179 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5405 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2262 alloc_slab_page mm/slub.c:1799 [inline] allocate_slab+0x26c/0x3c0 mm/slub.c:1944 new_slab mm/slub.c:2004 [inline] ___slab_alloc+0x8df/0xf20 mm/slub.c:3005 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3092 slab_alloc_node mm/slub.c:3183 [inline] kmem_cache_alloc_node+0x122/0x3f0 mm/slub.c:3267 __alloc_skb+0x215/0x340 net/core/skbuff.c:414 alloc_skb include/linux/skbuff.h:1300 [inline] ndisc_alloc_skb+0x134/0x320 net/ipv6/ndisc.c:420 ndisc_send_rs+0x37f/0x6f0 net/ipv6/ndisc.c:701 addrconf_dad_completed+0x37a/0xd30 net/ipv6/addrconf.c:4231 addrconf_dad_work+0x79f/0x1340 net/ipv6/addrconf.c:4141 process_one_work+0x996/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1353 [inline] free_pcp_prepare+0x549/0xd20 mm/page_alloc.c:1403 free_unref_page_prepare mm/page_alloc.c:3325 [inline] free_unref_page+0x19/0x690 mm/page_alloc.c:3420 qlink_free mm/kasan/quarantine.c:157 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0xa2/0xc0 mm/kasan/common.c:446 kasan_slab_alloc include/linux/kasan.h:224 [inline] slab_post_alloc_hook mm/slab.h:749 [inline] slab_alloc_node mm/slub.c:3217 [inline] kmem_cache_alloc_node+0x255/0x3f0 mm/slub.c:3267 __alloc_skb+0x215/0x340 net/core/skbuff.c:414 alloc_skb include/linux/skbuff.h:1300 [inline] alloc_skb_with_frags+0x93/0x730 net/core/skbuff.c:5988 sock_alloc_send_pskb+0x793/0x920 net/core/sock.c:2600 mld_newpack.isra.0+0x1be/0x750 net/ipv6/mcast.c:1746 add_grhead+0x283/0x360 net/ipv6/mcast.c:1849 add_grec+0x106a/0x1530 net/ipv6/mcast.c:1987 mld_send_initial_cr.part.0+0xf6/0x230 net/ipv6/mcast.c:2234 mld_send_initial_cr net/ipv6/mcast.c:1232 [inline] ipv6_mc_dad_complete+0x1d0/0x690 net/ipv6/mcast.c:2245 addrconf_dad_completed+0x9e8/0xd30 net/ipv6/addrconf.c:4211 addrconf_dad_work+0x79f/0x1340 net/ipv6/addrconf.c:4141 Memory state around the buggy address: ffff88802304aa80: 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc ffff88802304ab00: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb >ffff88802304ab80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88802304ac00: fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc ffff88802304ac80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. syzbot can test patches for this issue, for details see: https://goo.gl/tpsmEJ#testing-patches
