================================================================== BUG: KASAN: use-after-free in smc_fback_error_report+0x96/0xa0 net/smc/af_smc.c:664 Read of size 8 at addr ffff888013d970a8 by task kworker/u4:30/22384 CPU: 0 PID: 22384 Comm: kworker/u4:30 Not tainted 5.17.0-rc4-syzkaller-00051-gc5d9ae265b10 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0x8d/0x336 mm/kasan/report.c:255 __kasan_report mm/kasan/report.c:442 [inline] kasan_report.cold+0x83/0xdf mm/kasan/report.c:459 smc_fback_error_report+0x96/0xa0 net/smc/af_smc.c:664 sk_error_report+0x35/0x310 net/core/sock.c:340 tcp_write_err net/ipv4/tcp_timer.c:71 [inline] tcp_write_timeout net/ipv4/tcp_timer.c:276 [inline] tcp_retransmit_timer+0x20c2/0x3320 net/ipv4/tcp_timer.c:512 tcp_write_timer_handler+0x5e6/0xbc0 net/ipv4/tcp_timer.c:622 tcp_write_timer+0xa2/0x2b0 net/ipv4/tcp_timer.c:642 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1466 [inline] __run_timers.part.0+0x67c/0xa30 kernel/time/timer.c:1734 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1747 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:lock_release+0x3f1/0x720 kernel/locking/lockdep.c:5647 Code: 7e 83 f8 01 0f 85 8d 01 00 00 9c 58 f6 c4 02 0f 85 78 01 00 00 48 f7 04 24 00 02 00 00 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c5 48 c7 45 00 00 00 00 00 c7 45 08 00 00 00 00 48 8b 84 24 RSP: 0018:ffffc9001113fa88 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 3055485c2adabead RCX: ffffc9001113fad8 RDX: 1ffff11008c0d88a RSI: 0000000000000000 RDI: 0000000000000000 RBP: 1ffff92002227f53 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003 R13: 0000000000000004 R14: ffff88804606c458 R15: ffff88804606ba00 rcu_lock_release include/linux/rcupdate.h:273 [inline] rcu_read_unlock include/linux/rcupdate.h:727 [inline] inet_twsk_purge+0x503/0x7d0 net/ipv4/inet_timewait_sock.c:299 ops_exit_list+0x125/0x170 net/core/net_namespace.c:173 cleanup_net+0x4ea/0xb00 net/core/net_namespace.c:597 process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307 worker_thread+0x657/0x1110 kernel/workqueue.c:2454 kthread+0x2e9/0x3a0 kernel/kthread.c:377 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Allocated by task 4845: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:436 [inline] __kasan_slab_alloc+0x90/0xc0 mm/kasan/common.c:469 kasan_slab_alloc include/linux/kasan.h:260 [inline] slab_post_alloc_hook mm/slab.h:732 [inline] slab_alloc_node mm/slub.c:3230 [inline] kmem_cache_alloc_node+0x2c3/0x4f0 mm/slub.c:3266 alloc_task_struct_node kernel/fork.c:171 [inline] dup_task_struct kernel/fork.c:883 [inline] copy_process+0x5c4/0x7300 kernel/fork.c:1998 kernel_clone+0xe7/0xab0 kernel/fork.c:2555 __do_sys_clone+0xc8/0x110 kernel/fork.c:2672 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Freed by task 3646: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track+0x21/0x30 mm/kasan/common.c:45 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free+0x126/0x160 mm/kasan/common.c:328 kasan_slab_free include/linux/kasan.h:236 [inline] slab_free_hook mm/slub.c:1728 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1754 slab_free mm/slub.c:3509 [inline] kmem_cache_free+0xd7/0x370 mm/slub.c:3526 put_task_struct include/linux/sched/task.h:115 [inline] delayed_put_task_struct+0x1f6/0x340 kernel/exit.c:174 rcu_do_batch kernel/rcu/tree.c:2527 [inline] rcu_core+0x7b1/0x1820 kernel/rcu/tree.c:2778 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 Last potentially related work creation: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 __kasan_record_aux_stack+0xbe/0xd0 mm/kasan/generic.c:348 __call_rcu kernel/rcu/tree.c:3026 [inline] call_rcu+0xb1/0x740 kernel/rcu/tree.c:3106 put_task_struct_rcu_user+0x7f/0xb0 kernel/exit.c:180 context_switch kernel/sched/core.c:4990 [inline] __schedule+0xa9c/0x4910 kernel/sched/core.c:6296 schedule+0xd2/0x260 kernel/sched/core.c:6369 freezable_schedule include/linux/freezer.h:172 [inline] do_nanosleep+0x24e/0x690 kernel/time/hrtimer.c:2044 hrtimer_nanosleep+0x1f9/0x4a0 kernel/time/hrtimer.c:2097 common_nsleep+0xa2/0xc0 kernel/time/posix-timers.c:1227 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1267 [inline] __se_sys_clock_nanosleep kernel/time/posix-timers.c:1245 [inline] __x64_sys_clock_nanosleep+0x2f4/0x430 kernel/time/posix-timers.c:1245 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Second to last potentially related work creation: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 __kasan_record_aux_stack+0xbe/0xd0 mm/kasan/generic.c:348 __call_rcu kernel/rcu/tree.c:3026 [inline] call_rcu+0xb1/0x740 kernel/rcu/tree.c:3106 put_task_struct_rcu_user+0x7f/0xb0 kernel/exit.c:180 release_task+0xcd0/0x17e0 kernel/exit.c:226 wait_task_zombie kernel/exit.c:1121 [inline] wait_consider_task+0x3023/0x3c50 kernel/exit.c:1348 do_wait_thread kernel/exit.c:1411 [inline] do_wait+0x6ca/0xce0 kernel/exit.c:1528 kernel_wait4+0x14c/0x260 kernel/exit.c:1691 __do_sys_wait4+0x13f/0x150 kernel/exit.c:1719 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae The buggy address belongs to the object at ffff888013d95700 which belongs to the cache task_struct of size 7168 The buggy address is located 6568 bytes inside of 7168-byte region [ffff888013d95700, ffff888013d97300) The buggy address belongs to the page: page:ffffea00004f6400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x13d90 head:ffffea00004f6400 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff88802057e881 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000001 ffff888140006280 raw: 0000000000000000 0000000000040004 00000001ffffffff ffff88802057e881 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 4101, ts 958479957521, free_ts 958476099666 prep_new_page mm/page_alloc.c:2434 [inline] get_page_from_freelist+0xa72/0x2f50 mm/page_alloc.c:4165 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5389 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2271 alloc_slab_page mm/slub.c:1799 [inline] allocate_slab+0x27f/0x3c0 mm/slub.c:1944 new_slab mm/slub.c:2004 [inline] ___slab_alloc+0xbe1/0x12b0 mm/slub.c:3018 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3105 slab_alloc_node mm/slub.c:3196 [inline] kmem_cache_alloc_node+0x190/0x4f0 mm/slub.c:3266 alloc_task_struct_node kernel/fork.c:171 [inline] dup_task_struct kernel/fork.c:883 [inline] copy_process+0x5c4/0x7300 kernel/fork.c:1998 kernel_clone+0xe7/0xab0 kernel/fork.c:2555 __do_sys_clone+0xc8/0x110 kernel/fork.c:2672 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1352 [inline] free_pcp_prepare+0x374/0x870 mm/page_alloc.c:1404 free_unref_page_prepare mm/page_alloc.c:3325 [inline] free_unref_page+0x19/0x690 mm/page_alloc.c:3404 __unfreeze_partials+0x320/0x340 mm/slub.c:2536 qlink_free mm/kasan/quarantine.c:157 [inline] qlist_free_all+0x6d/0x160 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0xa2/0xc0 mm/kasan/common.c:446 kasan_slab_alloc include/linux/kasan.h:260 [inline] slab_post_alloc_hook mm/slab.h:732 [inline] slab_alloc_node mm/slub.c:3230 [inline] slab_alloc mm/slub.c:3238 [inline] kmem_cache_alloc+0x271/0x4b0 mm/slub.c:3243 vm_area_dup+0x88/0x2b0 kernel/fork.c:357 __split_vma+0xa5/0x550 mm/mmap.c:2720 split_vma+0x95/0xd0 mm/mmap.c:2778 mprotect_fixup+0x689/0x950 mm/mprotect.c:477 do_mprotect_pkey+0x532/0x980 mm/mprotect.c:639 __do_sys_mprotect mm/mprotect.c:665 [inline] __se_sys_mprotect mm/mprotect.c:662 [inline] __x64_sys_mprotect+0x74/0xb0 mm/mprotect.c:662 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Memory state around the buggy address: ffff888013d96f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888013d97000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888013d97080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888013d97100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888013d97180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 7e 83 jle 0xffffff85 2: f8 clc 3: 01 0f add %ecx,(%rdi) 5: 85 8d 01 00 00 9c test %ecx,-0x63ffffff(%rbp) b: 58 pop %rax c: f6 c4 02 test $0x2,%ah f: 0f 85 78 01 00 00 jne 0x18d 15: 48 f7 04 24 00 02 00 testq $0x200,(%rsp) 1c: 00 1d: 74 01 je 0x20 1f: fb sti 20: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 27: fc ff df * 2a: 48 01 c5 add %rax,%rbp <-- trapping instruction 2d: 48 c7 45 00 00 00 00 movq $0x0,0x0(%rbp) 34: 00 35: c7 45 08 00 00 00 00 movl $0x0,0x8(%rbp) 3c: 48 rex.W 3d: 8b .byte 0x8b 3e: 84 .byte 0x84 3f: 24 .byte 0x24