bisecting fixing commit since e6a95d8851f1e993269b2172595107061f9371ae building syzkaller on 0159583c3bcfe4ece6b839712327cd955aabee66 testing commit e6a95d8851f1e993269b2172595107061f9371ae with gcc (GCC) 8.1.0 kernel signature: f51eddae3f97d349a65c448419beef88cf1ff9f49b729cd933922418b1283115 run #0: crashed: BUG: unable to handle kernel run #1: crashed: KASAN: use-after-free Write in padata_parallel_worker run #2: crashed: KASAN: use-after-free in padata_parallel_worker run #3: crashed: BUG: unable to handle kernel paging request in corrupted run #4: crashed: KASAN: use-after-free Write in padata_parallel_worker run #5: crashed: KASAN: use-after-free in padata_parallel_worker run #6: crashed: KASAN: use-after-free Write in padata_parallel_worker run #7: crashed: BUG: unable to handle kernel NULL pointer dereference in corrupted run #8: crashed: KASAN: use-after-free Write in padata_parallel_worker run #9: crashed: KASAN: use-after-free Write in padata_parallel_worker testing current HEAD b850307b279cbd12ab8c654d1a3dfe55319cc475 testing commit b850307b279cbd12ab8c654d1a3dfe55319cc475 with gcc (GCC) 8.1.0 kernel signature: 2de1bd09b8526b7166a18dc075e9b2ae77748dc7d20736383265c32415d2ba7a run #0: crashed: KASAN: use-after-free Write in padata_parallel_worker run #1: crashed: KASAN: use-after-free Write in padata_parallel_worker run #2: crashed: KASAN: use-after-free Write in padata_parallel_worker run #3: crashed: KASAN: use-after-free Write in padata_parallel_worker run #4: crashed: KASAN: use-after-free Write in padata_parallel_worker run #5: crashed: KASAN: use-after-free Write in padata_parallel_worker run #6: crashed: KASAN: use-after-free Write in padata_parallel_worker run #7: crashed: BUG: unable to handle kernel run #8: crashed: KASAN: use-after-free in padata_parallel_worker run #9: crashed: KASAN: use-after-free Write in padata_parallel_worker revisions tested: 2, total time: 26m35.287278859s (build: 17m17.635195802s, test: 8m22.580966476s) the crash still happens on HEAD commit msg: Linux 4.14.184 crash: KASAN: use-after-free Write in padata_parallel_worker IPv6: ADDRCONF(NETDEV_CHANGE): bridge0: link becomes ready TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. 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IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bond: link becomes ready ================================================================== IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: link becomes ready BUG: KASAN: use-after-free in list_replace include/linux/list.h:141 [inline] BUG: KASAN: use-after-free in list_replace_init include/linux/list.h:149 [inline] BUG: KASAN: use-after-free in padata_parallel_worker+0x377/0x420 kernel/padata.c:76 Write of size 8 at addr ffff888096e675d8 by task kworker/0:2/3147 CPU: 0 PID: 3147 Comm: kworker/0:2 Not tainted 4.14.184-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: pencrypt padata_parallel_worker Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0xf7/0x13b lib/dump_stack.c:58 print_address_description.cold.7+0x9/0x1c9 mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report.cold.8+0x11a/0x2d3 mm/kasan/report.c:409 __asan_report_store8_noabort+0x17/0x20 mm/kasan/report.c:435 list_replace include/linux/list.h:141 [inline] list_replace_init include/linux/list.h:149 [inline] padata_parallel_worker+0x377/0x420 kernel/padata.c:76 process_one_work+0x79e/0x16c0 kernel/workqueue.c:2116 worker_thread+0xcc/0xee0 kernel/workqueue.c:2250 kthread+0x338/0x400 kernel/kthread.c:232 IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_1: link becomes ready bridge0: port 2(bridge_slave_1) entered blocking state ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Allocated by task 6959: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:551 __do_kmalloc mm/slab.c:3720 [inline] __kmalloc+0x15b/0x7b0 mm/slab.c:3729 kmalloc include/linux/slab.h:493 [inline] kzalloc include/linux/slab.h:661 [inline] tls_push_record+0xf6/0x14c0 net/tls/tls_sw.c:250 tls_sw_sendmsg+0x90b/0x10a0 net/tls/tls_sw.c:457 bridge0: port 2(bridge_slave_1) entered forwarding state inet_sendmsg+0x108/0x440 net/ipv4/af_inet.c:762 IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_team: link becomes ready sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xb5/0xf0 net/socket.c:656 IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_0: link becomes ready SYSC_sendto+0x1e3/0x2c0 net/socket.c:1763 IPv6: ADDRCONF(NETDEV_UP): veth0_to_bond: link is not ready SyS_sendto+0x9/0x10 net/socket.c:1731 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb Freed by task 6959: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3496 [inline] kfree+0xcc/0x270 mm/slab.c:3815 tls_push_record+0xd32/0x14c0 net/tls/tls_sw.c:293 tls_sw_sendmsg+0x90b/0x10a0 net/tls/tls_sw.c:457 inet_sendmsg+0x108/0x440 net/ipv4/af_inet.c:762 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xb5/0xf0 net/socket.c:656 SYSC_sendto+0x1e3/0x2c0 net/socket.c:1763 SyS_sendto+0x9/0x10 net/socket.c:1731 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb The buggy address belongs to the object at ffff888096e67580 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 88 bytes inside of 256-byte region [ffff888096e67580, ffff888096e67680) The buggy address belongs to the page: page:ffffea00025b99c0 count:1 mapcount:0 mapping:ffff888096e67080 index:0x0 flags: 0x1fffc0000000100(slab) raw: 01fffc0000000100 ffff888096e67080 0000000000000000 000000010000000c raw: ffffea00025b4120 ffffea00025c8920 ffff8880aa8007c0 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888096e67480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888096e67500: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc >ffff888096e67580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888096e67600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888096e67680: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00 ==================================================================