binder: 13143:13146 ioctl c018620b 20c9ffe8 returned -14 binder: 13143:13146 ioctl c018620b 20a27fe8 returned -14 ================================================================== BUG: KASAN: use-after-free in __read_once_size include/linux/compiler.h:243 [inline] BUG: KASAN: use-after-free in sk_dst_get include/net/sock.h:1695 [inline] BUG: KASAN: use-after-free in pppol2tp_connect+0x18a9/0x18f0 net/l2tp/l2tp_ppp.c:739 Read of size 8 at addr ffff8801d0314fd8 by task syz-executor3/13148 binder: 13143:13146 ioctl c018620b 20c9ffe8 returned -14 CPU: 0 PID: 13148 Comm: syz-executor3 Not tainted 4.9.77-g8788313 #16 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ffff8801c192fb28 ffffffff81d941c9 ffffea000740c400 ffff8801d0314fd8 0000000000000000 ffff8801d0314fd8 1ffff10038325f82 ffff8801c192fb60 ffffffff8153db93 ffff8801d0314fd8 0000000000000008 0000000000000000 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x128 lib/dump_stack.c:51 [] print_address_description+0x73/0x280 mm/kasan/report.c:252 [] kasan_report_error mm/kasan/report.c:351 [inline] [] kasan_report+0x275/0x360 mm/kasan/report.c:408 [] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:429 [] __read_once_size include/linux/compiler.h:243 [inline] [] sk_dst_get include/net/sock.h:1695 [inline] [] pppol2tp_connect+0x18a9/0x18f0 net/l2tp/l2tp_ppp.c:739 audit: type=1400 audit(1516318470.752:78): avc: denied { dyntransition } for pid=13193 comm="syz-executor4" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0 tclass=process permissive=1 [] SYSC_connect+0x1b6/0x310 net/socket.c:1562 [] SyS_connect+0x24/0x30 net/socket.c:1543 [] entry_SYSCALL_64_fastpath+0x29/0xe8 Allocated by task 11679: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 save_stack+0x43/0xd0 mm/kasan/kasan.c:505 set_track mm/kasan/kasan.c:517 [inline] kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:609 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:547 slab_post_alloc_hook mm/slab.h:417 [inline] slab_alloc_node mm/slub.c:2715 [inline] slab_alloc mm/slub.c:2723 [inline] kmem_cache_alloc+0xba/0x290 mm/slub.c:2728 sk_prot_alloc+0x65/0x2a0 net/core/sock.c:1332 sk_alloc+0x3a/0x3a0 net/core/sock.c:1394 inet6_create+0x2c8/0xde0 net/ipv6/af_inet6.c:198 __sock_create+0x3ab/0x640 net/socket.c:1182 sock_create net/socket.c:1222 [inline] SYSC_socket net/socket.c:1252 [inline] SyS_socket+0xf0/0x1b0 net/socket.c:1232 entry_SYSCALL_64_fastpath+0x29/0xe8 Freed by task 5144: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 save_stack+0x43/0xd0 mm/kasan/kasan.c:505 set_track mm/kasan/kasan.c:517 [inline] kasan_slab_free+0x72/0xc0 mm/kasan/kasan.c:582 slab_free_hook mm/slub.c:1355 [inline] slab_free_freelist_hook mm/slub.c:1377 [inline] slab_free mm/slub.c:2958 [inline] kmem_cache_free+0xc7/0x300 mm/slub.c:2980 sk_prot_free net/core/sock.c:1375 [inline] __sk_destruct+0x3c9/0x570 net/core/sock.c:1455 __rcu_reclaim kernel/rcu/rcu.h:118 [inline] rcu_do_batch kernel/rcu/tree.c:2789 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:3053 [inline] __rcu_process_callbacks kernel/rcu/tree.c:3020 [inline] rcu_process_callbacks+0x898/0x1300 kernel/rcu/tree.c:3037 __do_softirq+0x206/0x951 kernel/softirq.c:284 The buggy address belongs to the object at ffff8801d0314e00 which belongs to the cache UDPv6 of size 1496 The buggy address is located 472 bytes inside of 1496-byte region [ffff8801d0314e00, ffff8801d03153d8) The buggy address belongs to the page: page:ffffea000740c400 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 flags: 0x8000000000004080(slab|head) page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801d0314e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801d0314f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8801d0314f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801d0315000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801d0315080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================