batman_adv: batadv0: Interface deactivated: batadv_slave_0 batman_adv: batadv0: Removing interface: batadv_slave_0 batman_adv: batadv0: Interface deactivated: batadv_slave_1 batman_adv: batadv0: Removing interface: batadv_slave_1 ================================================================== BUG: KASAN: use-after-free in batadv_iv_ogm_schedule+0xe46/0xf30 net/batman-adv/bat_iv_ogm.c:958 Write of size 2 at addr ffff8800af2636a6 by task kworker/u4:7/10069 CPU: 0 PID: 10069 Comm: kworker/u4:7 Not tainted 4.19.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x15a/0x20d lib/dump_stack.c:113 print_address_description.cold.6+0x9/0x244 mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report mm/kasan/report.c:412 [inline] kasan_report.cold.7+0x242/0x305 mm/kasan/report.c:396 __asan_report_store2_noabort+0x17/0x20 mm/kasan/report.c:436 batadv_iv_ogm_schedule+0xe46/0xf30 net/batman-adv/bat_iv_ogm.c:958 batadv_iv_send_outstanding_bat_ogm_packet+0x4b2/0x7b0 net/batman-adv/bat_iv_ogm.c:1817 process_one_work+0x7b9/0x14f0 kernel/workqueue.c:2153 worker_thread+0x85/0xb60 kernel/workqueue.c:2296 kthread+0x324/0x3e0 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:413 Allocated by task 8646: save_stack mm/kasan/kasan.c:448 [inline] set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc.part.1+0x62/0xf0 mm/kasan/kasan.c:553 kasan_kmalloc+0xaf/0xc0 mm/kasan/kasan.c:538 kmem_cache_alloc_trace+0x13a/0x2f0 mm/slub.c:2733 kmalloc include/linux/slab.h:513 [inline] batadv_iv_ogm_iface_enable+0x11c/0x370 net/batman-adv/bat_iv_ogm.c:387 batadv_hardif_enable_interface+0x24d/0x9d0 net/batman-adv/hard-interface.c:776 batadv_softif_slave_add+0x7f/0xd0 net/batman-adv/soft-interface.c:894 do_set_master net/core/rtnetlink.c:2296 [inline] do_set_master+0x171/0x200 net/core/rtnetlink.c:2270 do_setlink+0x94c/0x2e40 net/core/rtnetlink.c:2430 rtnl_newlink+0x96a/0x1300 net/core/rtnetlink.c:3043 rtnetlink_rcv_msg+0x34f/0x950 net/core/rtnetlink.c:4730 netlink_rcv_skb+0x142/0x390 net/netlink/af_netlink.c:2454 rtnetlink_rcv+0x10/0x20 net/core/rtnetlink.c:4748 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline] netlink_unicast+0x443/0x660 net/netlink/af_netlink.c:1343 netlink_sendmsg+0x667/0xc60 net/netlink/af_netlink.c:1908 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg+0xac/0xf0 net/socket.c:631 __sys_sendto+0x1f2/0x2e0 net/socket.c:1788 __do_sys_sendto net/socket.c:1800 [inline] __se_sys_sendto net/socket.c:1796 [inline] __x64_sys_sendto+0xdc/0x1a0 net/socket.c:1796 do_syscall_64+0xda/0x540 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 3144: save_stack mm/kasan/kasan.c:448 [inline] set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x167/0x240 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 slab_free_hook mm/slub.c:1371 [inline] slab_free_freelist_hook mm/slub.c:1398 [inline] slab_free mm/slub.c:2953 [inline] kfree+0x130/0x360 mm/slub.c:3906 batadv_iv_ogm_iface_disable+0x34/0x70 net/batman-adv/bat_iv_ogm.c:406 batadv_hardif_disable_interface.cold.8+0x85f/0xdb4 net/batman-adv/hard-interface.c:872 batadv_softif_destroy_netlink+0x94/0x100 net/batman-adv/soft-interface.c:1147 default_device_exit_batch+0x239/0x3d0 net/core/dev.c:9545 ops_exit_list.isra.3+0xd3/0x120 net/core/net_namespace.c:156 cleanup_net+0x363/0x840 net/core/net_namespace.c:551 process_one_work+0x7b9/0x14f0 kernel/workqueue.c:2153 worker_thread+0x85/0xb60 kernel/workqueue.c:2296 kthread+0x324/0x3e0 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:413 The buggy address belongs to the object at ffff8800af263690 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 22 bytes inside of 32-byte region [ffff8800af263690, ffff8800af2636b0) The buggy address belongs to the page: page:ffffea0002bc98c0 count:1 mapcount:0 mapping:ffff88013ffbb800 index:0xffff8800af263d50 flags: 0xfff00000000100(slab) raw: 00fff00000000100 ffffea0002a774c8 ffffea0002d2f508 ffff88013ffbb800 raw: ffff8800af263d50 0000000000550053 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page allocated via order 0, migratetype Unmovable, gfp_mask 0x6012c0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY) set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook mm/page_alloc.c:1906 [inline] prep_new_page mm/page_alloc.c:1914 [inline] get_page_from_freelist+0x3033/0x4530 mm/page_alloc.c:3345 __alloc_pages_nodemask+0x39e/0x2670 mm/page_alloc.c:4370 alloc_pages_current+0xd6/0x1b0 mm/mempolicy.c:2093 alloc_pages include/linux/gfp.h:509 [inline] alloc_slab_page mm/slub.c:1438 [inline] allocate_slab mm/slub.c:1583 [inline] new_slab+0x4a9/0x850 mm/slub.c:1654 new_slab_objects mm/slub.c:2417 [inline] ___slab_alloc+0x648/0x980 mm/slub.c:2569 __slab_alloc.isra.22+0x78/0xe0 mm/slub.c:2609 slab_alloc_node mm/slub.c:2672 [inline] slab_alloc mm/slub.c:2714 [inline] __kmalloc+0x292/0x340 mm/slub.c:3747 kmalloc include/linux/slab.h:518 [inline] shmem_initxattrs+0x11a/0x1e0 mm/shmem.c:3121 security_inode_init_security security/security.c:502 [inline] security_inode_init_security+0x17f/0x2d0 security/security.c:475 shmem_mknod+0x98/0x1a0 mm/shmem.c:2805 vfs_mknod+0x419/0x6c0 fs/namei.c:3719 handle_create+0x19e/0x4d0 drivers/base/devtmpfs.c:211 handle drivers/base/devtmpfs.c:374 [inline] devtmpfsd drivers/base/devtmpfs.c:400 [inline] devtmpfsd+0x1ed/0x490 drivers/base/devtmpfs.c:379 kthread+0x324/0x3e0 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:413 Memory state around the buggy address: ffff8800af263580: fb fb fc fc fb fb fb fb fc fc fb fb fb fb fc fc ffff8800af263600: fb fb fb fb fc fc fb fb fb fb fc fc fb fb fb fb >ffff8800af263680: fc fc fb fb fb fb fc fc 00 00 00 00 fc fc 00 00 ^ ffff8800af263700: 00 05 fc fc 00 00 00 05 fc fc 00 00 00 05 fc fc ffff8800af263780: 00 00 00 05 fc fc 00 00 00 05 fc fc 00 00 00 05 ==================================================================