On Sat, Dec 3, 2016 at 1:58 PM, Andrey Konovalov <andreyk...@google.com> wrote: > +syzkal...@googlegroups.com > > On Sat, Dec 3, 2016 at 1:56 PM, Andrey Konovalov <andreyk...@google.com> > wrote: >> Hi! >> >> I'm seeing lots of the following error reports while running the >> syzkaller fuzzer. >> >> Reports appeared when I updated to 3c49de52 (Dec 2) from 2caceb32 (Dec 1). >> >> ================================================================== >> BUG: KASAN: use-after-free in worker_thread+0x17d8/0x18a0 >> Read of size 8 at addr ffff880067f3ecd8 by task kworker/3:1/774 >> >> page:ffffea00019fce00 count:1 mapcount:0 mapping: (null) >> index:0xffff880067f39c10 compound_mapcount: 0 >> flags: 0x500000000004080(slab|head) >> page dumped because: kasan: bad access detected >> >> CPU: 3 PID: 774 Comm: kworker/3:1 Not tainted 4.9.0-rc7+ #66 >> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 >> ffff88006c267838 ffffffff81f882da ffffffff6c25e338 1ffff1000d84ce9a >> ffffed000d84ce92 ffff88006c25e340 0000000041b58ab3 ffffffff8541e198 >> ffffffff81f88048 0000000100000000 0000000041b58ab3 ffffffff853d3ee8 >> Call Trace: >> [< inline >] __dump_stack lib/dump_stack.c:15 >> [<ffffffff81f882da>] dump_stack+0x292/0x398 lib/dump_stack.c:51 >> [< inline >] describe_address mm/kasan/report.c:262 >> [<ffffffff817e50d1>] kasan_report_error+0x121/0x560 mm/kasan/report.c:368 >> [< inline >] kasan_report mm/kasan/report.c:390 >> [<ffffffff817e560e>] __asan_report_load8_noabort+0x3e/0x40 >> mm/kasan/report.c:411 >> [<ffffffff81329b88>] worker_thread+0x17d8/0x18a0 kernel/workqueue.c:2228 >> [<ffffffff8133ebf3>] kthread+0x323/0x3e0 kernel/kthread.c:209 >> [<ffffffff84a2a22a>] ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:433 >> >> The buggy address belongs to the object at ffff880067f3e6d0 >> which belongs to the cache kmalloc-2048 of size 2048 >> The buggy address ffff880067f3ecd8 is located 1544 bytes inside >> of 2048-byte region [ffff880067f3e6d0, ffff880067f3eed0) >> >> Freed by task 0: >> [<ffffffff81203526>] save_stack_trace+0x16/0x20 >> arch/x86/kernel/stacktrace.c:57 >> [<ffffffff817e4173>] save_stack+0x43/0xd0 mm/kasan/kasan.c:495 >> [< inline >] set_track mm/kasan/kasan.c:507 >> [<ffffffff817e4a53>] kasan_slab_free+0x73/0xc0 mm/kasan/kasan.c:571 >> [< inline >] slab_free_hook mm/slub.c:1352 >> [< inline >] slab_free_freelist_hook mm/slub.c:1374 >> [< inline >] slab_free mm/slub.c:2951 >> [<ffffffff817e0eb7>] kfree+0xe7/0x2b0 mm/slub.c:3871 >> [< inline >] sk_prot_free net/core/sock.c:1372 >> [<ffffffff831ea1c7>] __sk_destruct+0x5c7/0x6e0 net/core/sock.c:1445 >> [<ffffffff831f3517>] sk_destruct+0x47/0x80 net/core/sock.c:1453 >> [<ffffffff831f35a7>] __sk_free+0x57/0x230 net/core/sock.c:1461 >> [<ffffffff831f37a3>] sk_free+0x23/0x30 net/core/sock.c:1472 >> [< inline >] sock_put include/net/sock.h:1591 >> [<ffffffff8348ca9c>] deferred_put_nlk_sk+0x2c/0x40 >> net/netlink/af_netlink.c:671 >> [< inline >] __rcu_reclaim kernel/rcu/rcu.h:118 >> [<ffffffff8146d42f>] rcu_do_batch.isra.67+0x8ff/0xc50 kernel/rcu/tree.c:2776 >> [< inline >] invoke_rcu_callbacks kernel/rcu/tree.c:3040 >> [< inline >] __rcu_process_callbacks kernel/rcu/tree.c:3007 >> [<ffffffff8146e097>] rcu_process_callbacks+0x2b7/0xba0 >> kernel/rcu/tree.c:3024 >> [<ffffffff84a2d08b>] __do_softirq+0x2fb/0xb63 kernel/softirq.c:284 >> >> Allocated by task 10748: >> [<ffffffff81203526>] save_stack_trace+0x16/0x20 >> arch/x86/kernel/stacktrace.c:57 >> [<ffffffff817e4173>] save_stack+0x43/0xd0 mm/kasan/kasan.c:495 >> [< inline >] set_track mm/kasan/kasan.c:507 >> [<ffffffff817e43fd>] kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:598 >> [<ffffffff817e0050>] __kmalloc+0xa0/0x2d0 mm/slub.c:3734 >> [< inline >] kmalloc include/linux/slab.h:495 >> [<ffffffff831e4c01>] sk_prot_alloc+0x101/0x2a0 net/core/sock.c:1333 >> [<ffffffff831efd15>] sk_alloc+0x105/0x1000 net/core/sock.c:1389 >> [<ffffffff8348ad46>] __netlink_create+0x66/0x1d0 >> net/netlink/af_netlink.c:588 >> [<ffffffff8348cdab>] netlink_create+0x2fb/0x500 net/netlink/af_netlink.c:647 >> [<ffffffff831dd1d6>] __sock_create+0x4f6/0x880 net/socket.c:1168 >> [< inline >] sock_create net/socket.c:1208 >> [< inline >] SYSC_socket net/socket.c:1238 >> [<ffffffff831dd799>] SyS_socket+0xf9/0x230 net/socket.c:1218 >> [<ffffffff84a29fc1>] entry_SYSCALL_64_fastpath+0x1f/0xc2 >> >> Memory state around the buggy address: >> ffff880067f3eb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >> ffff880067f3ec00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >>>ffff880067f3ec80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >> ^ >> ffff880067f3ed00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >> ffff880067f3ed80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >> ==================================================================
Here is another report that looks related: ================================================================== BUG: KASAN: use-after-free in __list_add+0x236/0x2c0 Read of size 8 at addr ffff880068854780 by task ksoftirqd/2/20 page:ffffea0001a21400 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 flags: 0x500000000004080(slab|head) page dumped because: kasan: bad access detected CPU: 2 PID: 20 Comm: ksoftirqd/2 Not tainted 4.9.0-rc7+ #66 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 ffff88006daf6578 ffffffff81f882da ffffffff6daf62a0 1ffff1000db5ec42 ffffed000db5ec3a dffffc0000000000 0000000041b58ab3 ffffffff8541e198 ffffffff81f88048 ffff88006dac3610 ffff88006daf6300 0000000000000802 Call Trace: [< inline >] __dump_stack lib/dump_stack.c:15 [<ffffffff81f882da>] dump_stack+0x292/0x398 lib/dump_stack.c:51 [< inline >] describe_address mm/kasan/report.c:262 [<ffffffff817e50d1>] kasan_report_error+0x121/0x560 mm/kasan/report.c:368 [< inline >] kasan_report mm/kasan/report.c:390 [<ffffffff817e560e>] __asan_report_load8_noabort+0x3e/0x40 mm/kasan/report.c:411 [<ffffffff8200c166>] __list_add+0x236/0x2c0 lib/list_debug.c:30 [< inline >] list_add_tail include/linux/list.h:77 [<ffffffff8131e295>] insert_work+0x175/0x4b0 kernel/workqueue.c:1298 [<ffffffff8131eb52>] __queue_work+0x582/0x11e0 kernel/workqueue.c:1459 [<ffffffff81320c21>] queue_work_on+0x231/0x240 kernel/workqueue.c:1484 [< inline >] queue_work include/linux/workqueue.h:474 [< inline >] schedule_work include/linux/workqueue.h:532 [<ffffffff8348c8cc>] netlink_sock_destruct+0x23c/0x2d0 net/netlink/af_netlink.c:361 [<ffffffff831e9ce1>] __sk_destruct+0xe1/0x6e0 net/core/sock.c:1423 [<ffffffff831f3517>] sk_destruct+0x47/0x80 net/core/sock.c:1453 [<ffffffff831f35a7>] __sk_free+0x57/0x230 net/core/sock.c:1461 [<ffffffff831f37a3>] sk_free+0x23/0x30 net/core/sock.c:1472 [< inline >] sock_put include/net/sock.h:1591 [<ffffffff8348ca9c>] deferred_put_nlk_sk+0x2c/0x40 net/netlink/af_netlink.c:671 [< inline >] __rcu_reclaim kernel/rcu/rcu.h:118 [<ffffffff8146d42f>] rcu_do_batch.isra.67+0x8ff/0xc50 kernel/rcu/tree.c:2776 [< inline >] invoke_rcu_callbacks kernel/rcu/tree.c:3040 [< inline >] __rcu_process_callbacks kernel/rcu/tree.c:3007 [<ffffffff8146e097>] rcu_process_callbacks+0x2b7/0xba0 kernel/rcu/tree.c:3024 [<ffffffff84a2d08b>] __do_softirq+0x2fb/0xb63 kernel/softirq.c:284 [<ffffffff812d38c0>] run_ksoftirqd+0x20/0x60 kernel/softirq.c:676 [<ffffffff81350132>] smpboot_thread_fn+0x562/0x860 kernel/smpboot.c:163 [<ffffffff8133ebf3>] kthread+0x323/0x3e0 kernel/kthread.c:209 [<ffffffff84a2a22a>] ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:433 The buggy address belongs to the object at ffff880068854170 which belongs to the cache kmalloc-2048 of size 2048 The buggy address ffff880068854780 is located 1552 bytes inside of 2048-byte region [ffff880068854170, ffff880068854970) Freed by task 20: [<ffffffff81203526>] save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 [<ffffffff817e4173>] save_stack+0x43/0xd0 mm/kasan/kasan.c:495 [< inline >] set_track mm/kasan/kasan.c:507 [<ffffffff817e4a53>] kasan_slab_free+0x73/0xc0 mm/kasan/kasan.c:571 [< inline >] slab_free_hook mm/slub.c:1352 [< inline >] slab_free_freelist_hook mm/slub.c:1374 [< inline >] slab_free mm/slub.c:2951 [<ffffffff817e0eb7>] kfree+0xe7/0x2b0 mm/slub.c:3871 [< inline >] sk_prot_free net/core/sock.c:1372 [<ffffffff831ea1c7>] __sk_destruct+0x5c7/0x6e0 net/core/sock.c:1445 [<ffffffff831f3517>] sk_destruct+0x47/0x80 net/core/sock.c:1453 [<ffffffff831f35a7>] __sk_free+0x57/0x230 net/core/sock.c:1461 [<ffffffff831f37a3>] sk_free+0x23/0x30 net/core/sock.c:1472 [< inline >] sock_put include/net/sock.h:1591 [<ffffffff8348ca9c>] deferred_put_nlk_sk+0x2c/0x40 net/netlink/af_netlink.c:671 [< inline >] __rcu_reclaim kernel/rcu/rcu.h:118 [<ffffffff8146d42f>] rcu_do_batch.isra.67+0x8ff/0xc50 kernel/rcu/tree.c:2776 [< inline >] invoke_rcu_callbacks kernel/rcu/tree.c:3040 [< inline >] __rcu_process_callbacks kernel/rcu/tree.c:3007 [<ffffffff8146e097>] rcu_process_callbacks+0x2b7/0xba0 kernel/rcu/tree.c:3024 [<ffffffff84a2d08b>] __do_softirq+0x2fb/0xb63 kernel/softirq.c:284 Allocated by task 9480: [<ffffffff81203526>] save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 [<ffffffff817e4173>] save_stack+0x43/0xd0 mm/kasan/kasan.c:495 [< inline >] set_track mm/kasan/kasan.c:507 [<ffffffff817e43fd>] kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:598 [<ffffffff817e0050>] __kmalloc+0xa0/0x2d0 mm/slub.c:3734 [< inline >] kmalloc include/linux/slab.h:495 [<ffffffff831e4c01>] sk_prot_alloc+0x101/0x2a0 net/core/sock.c:1333 [<ffffffff831efd15>] sk_alloc+0x105/0x1000 net/core/sock.c:1389 [<ffffffff8348ad46>] __netlink_create+0x66/0x1d0 net/netlink/af_netlink.c:588 [<ffffffff8348cdab>] netlink_create+0x2fb/0x500 net/netlink/af_netlink.c:647 [<ffffffff831dd1d6>] __sock_create+0x4f6/0x880 net/socket.c:1168 [< inline >] sock_create net/socket.c:1208 [< inline >] SYSC_socket net/socket.c:1238 [<ffffffff831dd799>] SyS_socket+0xf9/0x230 net/socket.c:1218 [<ffffffff84a29fc1>] entry_SYSCALL_64_fastpath+0x1f/0xc2 Memory state around the buggy address: ffff880068854680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff880068854700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff880068854780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff880068854800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff880068854880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================