================================================================== 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 ffff888084f53fc5 by task kworker/0:17/11830 CPU: 0 PID: 11830 Comm: kworker/0:17 Not tainted 6.1.82-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 Workqueue: 0x0 (rcu_gp) 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:ffffc900035dfba8 EFLAGS: 00000286 RAX: 30694df802fcc700 RBX: ffff888021d08034 RCX: ffffffff91c8e103 RDX: dffffc0000000000 RSI: ffffffff8aebee40 RDI: ffff8880731f95f8 RBP: ffffc900035dfbf0 R08: dffffc0000000000 R09: ffffed1017307541 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff8880731f8000 R13: 1ffff110173076eb R14: ffff8880b983aa00 R15: ffff8880b983b758 context_switch kernel/sched/core.c:5248 [inline] __schedule+0x1435/0x4550 kernel/sched/core.c:6558 schedule+0xbf/0x180 kernel/sched/core.c:6634 worker_thread+0xe9d/0x1200 kernel/workqueue.c:2460 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:307 Allocated by task 4662: 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 ffff888084f53880 which belongs to the cache net_namespace of size 6976 The buggy address is located 1861 bytes inside of 6976-byte region [ffff888084f53880, ffff888084f553c0) The buggy address belongs to the physical page: page:ffffea000213d400 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888084f554c0 pfn:0x84f50 head:ffffea000213d400 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff88807a1c2ec1 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0001f04600 dead000000000002 ffff888140009500 raw: ffff888084f554c0 0000000080040003 00000001ffffffff ffff88807a1c2ec1 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 4271, tgid 4271 (syz-executor.3), ts 193208319526, free_ts 193206837345 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_large_kmalloc+0xfb/0x190 mm/slab_common.c:932 skb_free_head net/core/skbuff.c:762 [inline] skb_release_data+0x5de/0x7a0 net/core/skbuff.c:791 skb_release_all net/core/skbuff.c:856 [inline] __kfree_skb net/core/skbuff.c:870 [inline] consume_skb+0xa3/0x140 net/core/skbuff.c:1035 netlink_recvmsg+0x61a/0x1180 net/netlink/af_netlink.c:1952 ____sys_recvmsg+0x285/0x530 ___sys_recvmsg net/socket.c:2775 [inline] __sys_recvmsg+0x2e9/0x3d0 net/socket.c:2805 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 Memory state around the buggy address: ffff888084f53e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888084f53f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888084f53f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888084f54000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888084f54080: 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