================================================================== BUG: KASAN: use-after-free in tcp_probe_timer net/ipv4/tcp_timer.c:388 [inline] BUG: KASAN: use-after-free in tcp_write_timer_handler+0x7ef/0x930 net/ipv4/tcp_timer.c:652 Read of size 1 at addr ffff8880a93b5c05 by task syz-executor.0/10123 CPU: 0 PID: 10123 Comm: syz-executor.0 Not tainted 6.1.82-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 print_address_description mm/kasan/report.c:284 [inline] print_report+0x15f/0x4f0 mm/kasan/report.c:395 kasan_report+0x136/0x160 mm/kasan/report.c:495 tcp_probe_timer net/ipv4/tcp_timer.c:388 [inline] tcp_write_timer_handler+0x7ef/0x930 net/ipv4/tcp_timer.c:652 tcp_write_timer+0x12e/0x280 net/ipv4/tcp_timer.c:665 call_timer_fn+0x1ad/0x6b0 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1519 [inline] __run_timers+0x67c/0x890 kernel/time/timer.c:1790 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1803 __do_softirq+0x2e9/0xa4c kernel/softirq.c:571 invoke_softirq kernel/softirq.c:445 [inline] __irq_exit_rcu+0x155/0x240 kernel/softirq.c:650 irq_exit_rcu+0x5/0x20 kernel/softirq.c:662 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653 RIP: 0010:finish_task_switch+0x1d3/0x810 kernel/sched/core.c:5124 Code: 38 0b 00 48 83 c4 08 4c 89 f7 e8 98 30 00 00 0f 1f 44 00 00 4c 89 f7 e8 5b b0 34 09 e8 c6 2a 32 00 fb 49 8d bc 24 f8 15 00 00 <48> 89 f8 48 c1 e8 03 49 bd 00 00 00 00 00 fc ff df 42 0f b6 04 28 RSP: 0018:ffffc9000327e928 EFLAGS: 00000282 RAX: 1fb8e78b7e25b100 RBX: ffff88807be5bbb4 RCX: ffffffff816abf3a RDX: dffffc0000000000 RSI: ffffffff8aebee40 RDI: ffff8880260c6f38 RBP: ffffc9000327e970 R08: dffffc0000000000 R09: fffffbfff2092c55 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff8880260c5940 R13: 1ffff110173076eb R14: ffff8880b983aa00 R15: ffff8880b983b758 context_switch kernel/sched/core.c:5248 [inline] __schedule+0x1435/0x4550 kernel/sched/core.c:6558 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6727 preempt_schedule+0xd9/0xe0 kernel/sched/core.c:6751 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34 unwind_next_frame+0x1a55/0x2220 arch/x86/kernel/unwind_orc.c:629 arch_stack_walk+0x10d/0x140 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122 save_stack+0xf6/0x1e0 mm/page_owner.c:127 __set_page_owner+0x26/0x390 mm/page_owner.c:190 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x18d/0x1b0 mm/page_alloc.c:2513 prep_new_page mm/page_alloc.c:2520 [inline] get_page_from_freelist+0x31a1/0x3320 mm/page_alloc.c:4279 __alloc_pages+0x28d/0x770 mm/page_alloc.c:5545 __alloc_pages_bulk+0x74a/0xd60 mm/page_alloc.c:5493 vm_area_alloc_pages mm/vmalloc.c:2955 [inline] __vmalloc_area_node mm/vmalloc.c:3051 [inline] __vmalloc_node_range+0x743/0x1460 mm/vmalloc.c:3223 __vmalloc_node mm/vmalloc.c:3288 [inline] vzalloc+0x75/0x80 mm/vmalloc.c:3361 alloc_counters+0xd0/0x7b0 net/ipv4/netfilter/ip_tables.c:801 copy_entries_to_user net/ipv4/netfilter/ip_tables.c:823 [inline] get_entries net/ipv4/netfilter/ip_tables.c:1024 [inline] do_ipt_get_ctl+0xeb1/0x1890 net/ipv4/netfilter/ip_tables.c:1662 nf_getsockopt+0x28e/0x2b0 net/netfilter/nf_sockopt.c:116 ip_getsockopt+0x21a/0x2d0 net/ipv4/ip_sockglue.c:1826 tcp_getsockopt+0x15c/0x1c0 net/ipv4/tcp.c:4443 __sys_getsockopt+0x2b2/0x5d0 net/socket.c:2327 __do_sys_getsockopt net/socket.c:2342 [inline] __se_sys_getsockopt net/socket.c:2339 [inline] __x64_sys_getsockopt+0xb1/0xc0 net/socket.c:2339 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fb222a7f94a Code: c4 c1 e0 1a 0d 00 00 04 00 89 01 e9 e0 fe ff ff e8 3b 05 00 00 66 2e 0f 1f 84 00 00 00 00 00 90 49 89 ca b8 37 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 06 c3 0f 1f 44 00 00 48 c7 c2 b0 ff ff ff f7 RSP: 002b:00007ffc6320fcc8 EFLAGS: 00000216 ORIG_RAX: 0000000000000037 RAX: ffffffffffffffda RBX: 00007ffc6320fd50 RCX: 00007fb222a7f94a RDX: 0000000000000041 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 0000000000000003 R08: 00007ffc6320fcec R09: 00007ffc63210107 R10: 00007ffc6320fd50 R11: 0000000000000216 R12: 00007fb222b7cd00 R13: 00007ffc6320fcec R14: 0000000000000000 R15: 00007fb222b7eec0 Allocated by task 11216: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 __kasan_slab_alloc+0x65/0x70 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x52/0x3a0 mm/slab.h:737 slab_alloc_node mm/slub.c:3398 [inline] slab_alloc mm/slub.c:3406 [inline] __kmem_cache_alloc_lru mm/slub.c:3413 [inline] kmem_cache_alloc+0x10c/0x2d0 mm/slub.c:3422 kmem_cache_zalloc include/linux/slab.h:682 [inline] net_alloc net/core/net_namespace.c:410 [inline] copy_net_ns+0x143/0x5d0 net/core/net_namespace.c:465 create_new_namespaces+0x425/0x7a0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x11e/0x170 kernel/nsproxy.c:226 ksys_unshare+0x580/0xb20 kernel/fork.c:3203 __do_sys_unshare kernel/fork.c:3274 [inline] __se_sys_unshare kernel/fork.c:3272 [inline] __x64_sys_unshare+0x34/0x40 kernel/fork.c:3272 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x63/0xcd Last potentially related work creation: kasan_save_stack+0x3b/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xb0/0xc0 mm/kasan/generic.c:486 insert_work+0x54/0x3d0 kernel/workqueue.c:1361 __queue_work+0xb4b/0xf90 kernel/workqueue.c:1520 call_timer_fn+0x1ad/0x6b0 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1514 [inline] __run_timers+0x6a8/0x890 kernel/time/timer.c:1790 __do_softirq+0x2e9/0xa4c kernel/softirq.c:571 Second to last potentially related work creation: kasan_save_stack+0x3b/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xb0/0xc0 mm/kasan/generic.c:486 insert_work+0x54/0x3d0 kernel/workqueue.c:1361 __queue_work+0xb4b/0xf90 kernel/workqueue.c:1520 call_timer_fn+0x1ad/0x6b0 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1514 [inline] __run_timers+0x6a8/0x890 kernel/time/timer.c:1790 __do_softirq+0x2e9/0xa4c kernel/softirq.c:571 The buggy address belongs to the object at ffff8880a93b54c0 which belongs to the cache net_namespace of size 6976 The buggy address is located 1861 bytes inside of 6976-byte region [ffff8880a93b54c0, ffff8880a93b7000) The buggy address belongs to the physical page: page:ffffea0002a4ec00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880a93b54c0 pfn:0xa93b0 head:ffffea0002a4ec00 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff888012767201 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000001 ffff888012626500 raw: ffff8880a93b54c0 0000000080040001 00000001ffffffff ffff888012767201 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 1616, tgid 1613 (syz-executor.3), ts 1020505916316, free_ts 1020497577704 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x18d/0x1b0 mm/page_alloc.c:2513 prep_new_page mm/page_alloc.c:2520 [inline] get_page_from_freelist+0x31a1/0x3320 mm/page_alloc.c:4279 __alloc_pages+0x28d/0x770 mm/page_alloc.c:5545 alloc_slab_page+0x6a/0x150 mm/slub.c:1794 allocate_slab mm/slub.c:1939 [inline] new_slab+0x84/0x2d0 mm/slub.c:1992 ___slab_alloc+0xc20/0x1270 mm/slub.c:3180 __slab_alloc mm/slub.c:3279 [inline] slab_alloc_node mm/slub.c:3364 [inline] slab_alloc mm/slub.c:3406 [inline] __kmem_cache_alloc_lru mm/slub.c:3413 [inline] kmem_cache_alloc+0x1a5/0x2d0 mm/slub.c:3422 kmem_cache_zalloc include/linux/slab.h:682 [inline] net_alloc net/core/net_namespace.c:410 [inline] copy_net_ns+0x143/0x5d0 net/core/net_namespace.c:465 create_new_namespaces+0x425/0x7a0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x11e/0x170 kernel/nsproxy.c:226 ksys_unshare+0x580/0xb20 kernel/fork.c:3203 __do_sys_unshare kernel/fork.c:3274 [inline] __se_sys_unshare kernel/fork.c:3272 [inline] __x64_sys_unshare+0x34/0x40 kernel/fork.c:3272 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x63/0xcd page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1440 [inline] free_pcp_prepare mm/page_alloc.c:1490 [inline] free_unref_page_prepare+0xf63/0x1120 mm/page_alloc.c:3358 free_unref_page+0x33/0x3e0 mm/page_alloc.c:3453 free_slab mm/slub.c:2031 [inline] discard_slab mm/slub.c:2037 [inline] __unfreeze_partials+0x1b7/0x210 mm/slub.c:2586 put_cpu_partial+0x17b/0x250 mm/slub.c:2662 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x76/0xe0 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x156/0x170 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x1f/0x70 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x52/0x3a0 mm/slab.h:737 slab_alloc_node mm/slub.c:3398 [inline] slab_alloc mm/slub.c:3406 [inline] __kmem_cache_alloc_lru mm/slub.c:3413 [inline] kmem_cache_alloc_lru+0x10c/0x2d0 mm/slub.c:3429 __d_alloc+0x31/0x710 fs/dcache.c:1770 d_alloc fs/dcache.c:1850 [inline] d_alloc_name+0xe0/0x290 fs/dcache.c:1912 simple_fill_super+0x2ee/0x600 fs/libfs.c:684 nfsd_fill_super+0x80/0x110 fs/nfsd/nfsctl.c:1366 vfs_get_super fs/super.c:1200 [inline] get_tree_keyed+0xd7/0x180 fs/super.c:1256 vfs_get_tree+0x88/0x270 fs/super.c:1562 do_new_mount+0x2ba/0xb40 fs/namespace.c:3051 Memory state around the buggy address: ffff8880a93b5b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a93b5b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880a93b5c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880a93b5c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a93b5d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 0b 00 or (%rax),%eax 2: 48 83 c4 08 add $0x8,%rsp 6: 4c 89 f7 mov %r14,%rdi 9: e8 98 30 00 00 call 0x30a6 e: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 13: 4c 89 f7 mov %r14,%rdi 16: e8 5b b0 34 09 call 0x934b076 1b: e8 c6 2a 32 00 call 0x322ae6 20: fb sti 21: 49 8d bc 24 f8 15 00 lea 0x15f8(%r12),%rdi 28: 00 * 29: 48 89 f8 mov %rdi,%rax <-- trapping instruction 2c: 48 c1 e8 03 shr $0x3,%rax 30: 49 bd 00 00 00 00 00 movabs $0xdffffc0000000000,%r13 37: fc ff df 3a: 42 0f b6 04 28 movzbl (%rax,%r13,1),%eax