================================================================== BUG: KASAN: use-after-free in tcp_probe_timer net/ipv4/tcp_timer.c:360 [inline] BUG: KASAN: use-after-free in tcp_write_timer_handler+0x8c6/0x8d0 net/ipv4/tcp_timer.c:596 Read of size 4 at addr ffff8880a5c3a650 by task syz-executor.5/15645 CPU: 1 PID: 15645 Comm: syz-executor.5 Not tainted 5.2.0+ #67 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 print_address_description.cold+0xd4/0x306 mm/kasan/report.c:351 __kasan_report.cold+0x1b/0x36 mm/kasan/report.c:482 kasan_report+0x12/0x17 mm/kasan/common.c:612 __asan_report_load4_noabort+0x14/0x20 mm/kasan/generic_report.c:131 tcp_probe_timer net/ipv4/tcp_timer.c:360 [inline] tcp_write_timer_handler+0x8c6/0x8d0 net/ipv4/tcp_timer.c:596 tcp_write_timer+0xa8/0x1e0 net/ipv4/tcp_timer.c:612 call_timer_fn+0x1ac/0x780 kernel/time/timer.c:1322 expire_timers kernel/time/timer.c:1366 [inline] __run_timers kernel/time/timer.c:1685 [inline] __run_timers kernel/time/timer.c:1653 [inline] run_timer_softirq+0x697/0x17a0 kernel/time/timer.c:1698 __do_softirq+0x262/0x98c kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x19b/0x1e0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:537 [inline] smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1095 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:828 RIP: 0010:arch_local_save_flags arch/x86/include/asm/paravirt.h:762 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/paravirt.h:784 [inline] RIP: 0010:lock_acquire+0x9b/0x410 kernel/locking/lockdep.c:4408 Code: d2 88 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 0f 85 2e 03 00 00 48 83 3d 85 1a 7a 07 00 0f 84 bb 02 00 00 9c 58 <0f> 1f 44 00 00 48 ba 00 00 00 00 00 fc ff df 48 89 45 c8 48 c7 c0 RSP: 0018:ffff88809341f3a0 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000286 RBX: 0000000000000000 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffff888056f4898c RBP: ffff88809341f3e8 R08: 0000000000000000 R09: 0000000000000000 R10: fffffbfff1349ef7 R11: ffffffff89a4f7bf R12: ffffffff88dabf80 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000002 rcu_lock_acquire include/linux/rcupdate.h:208 [inline] rcu_read_lock include/linux/rcupdate.h:592 [inline] rt6_get_cookie include/net/ip6_fib.h:263 [inline] sctp_v6_get_dst+0x87a/0x1d10 net/sctp/ipv6.c:363 sctp_transport_route+0x12d/0x360 net/sctp/transport.c:297 sctp_assoc_add_peer+0x53e/0xfc0 net/sctp/associola.c:661 sctp_process_param net/sctp/sm_make_chunk.c:2521 [inline] sctp_process_init+0x2453/0x2ab0 net/sctp/sm_make_chunk.c:2342 sctp_sf_do_unexpected_init net/sctp/sm_statefuns.c:1541 [inline] sctp_sf_do_unexpected_init.isra.0+0x7cd/0x1350 net/sctp/sm_statefuns.c:1441 sctp_sf_do_5_2_1_siminit+0x35/0x40 net/sctp/sm_statefuns.c:1670 sctp_do_sm+0x121/0x5170 net/sctp/sm_sideeffect.c:1152 sctp_assoc_bh_rcv+0x356/0x680 net/sctp/associola.c:1057 sctp_inq_push+0x1e4/0x280 net/sctp/inqueue.c:80 sctp_backlog_rcv+0x196/0xbc0 net/sctp/input.c:339 sk_backlog_rcv include/net/sock.h:945 [inline] __release_sock+0x129/0x390 net/core/sock.c:2418 release_sock+0x59/0x1c0 net/core/sock.c:2934 sctp_connect net/sctp/socket.c:4828 [inline] sctp_inet_connect+0x15d/0x1c0 net/sctp/socket.c:4841 __sys_connect+0x264/0x330 net/socket.c:1828 __do_sys_connect net/socket.c:1839 [inline] __se_sys_connect net/socket.c:1836 [inline] __x64_sys_connect+0x73/0xb0 net/socket.c:1836 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459829 Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fce56eb2c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459829 RDX: 000000000000001c RSI: 0000000020000200 RDI: 0000000000000003 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fce56eb36d4 R13: 00000000004bfd71 R14: 00000000004d1ab8 R15: 00000000ffffffff Allocated by task 21564: save_stack+0x23/0x90 mm/kasan/common.c:69 set_track mm/kasan/common.c:77 [inline] __kasan_kmalloc mm/kasan/common.c:487 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:460 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:495 slab_post_alloc_hook mm/slab.h:520 [inline] slab_alloc mm/slab.c:3319 [inline] kmem_cache_alloc+0x121/0x710 mm/slab.c:3483 getname_flags fs/namei.c:138 [inline] getname_flags+0xd6/0x5b0 fs/namei.c:128 getname fs/namei.c:209 [inline] user_path_create fs/namei.c:3692 [inline] do_symlinkat+0xe1/0x290 fs/namei.c:4147 __do_sys_symlink fs/namei.c:4173 [inline] __se_sys_symlink fs/namei.c:4171 [inline] __x64_sys_symlink+0x59/0x80 fs/namei.c:4171 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 21564: save_stack+0x23/0x90 mm/kasan/common.c:69 set_track mm/kasan/common.c:77 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:449 kasan_slab_free+0xe/0x10 mm/kasan/common.c:457 __cache_free mm/slab.c:3425 [inline] kmem_cache_free+0x86/0x320 mm/slab.c:3693 putname+0xef/0x130 fs/namei.c:259 filename_create+0x26f/0x4f0 fs/namei.c:3657 user_path_create fs/namei.c:3692 [inline] do_symlinkat+0xf3/0x290 fs/namei.c:4147 __do_sys_symlink fs/namei.c:4173 [inline] __se_sys_symlink fs/namei.c:4171 [inline] __x64_sys_symlink+0x59/0x80 fs/namei.c:4171 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8880a5c3a580 which belongs to the cache names_cache of size 4096 The buggy address is located 208 bytes inside of 4096-byte region [ffff8880a5c3a580, ffff8880a5c3b580) The buggy address belongs to the page: page:ffffea0002970e80 refcount:1 mapcount:0 mapping:ffff88821bc46380 index:0x0 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea00017bde08 ffffea00019fa688 ffff88821bc46380 raw: 0000000000000000 ffff8880a5c3a580 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a5c3a500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880a5c3a580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880a5c3a600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880a5c3a680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a5c3a700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================