================================================================== BUG: KASAN: use-after-free in tcp_probe_timer net/ipv4/tcp_timer.c:378 [inline] BUG: KASAN: use-after-free in tcp_write_timer_handler net/ipv4/tcp_timer.c:624 [inline] BUG: KASAN: use-after-free in tcp_write_timer_handler+0x998/0x9f0 net/ipv4/tcp_timer.c:594 Read of size 1 at addr ffff88801e16bfc5 by task kworker/0:7/3694 CPU: 0 PID: 3694 Comm: kworker/0:7 Not tainted 6.0.0-syzkaller-02801-gfa182ea26ff0 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022 Workqueue: events nsim_dev_trap_report_work Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:317 [inline] print_report.cold+0x2ba/0x719 mm/kasan/report.c:433 kasan_report+0xb1/0x1e0 mm/kasan/report.c:495 tcp_probe_timer net/ipv4/tcp_timer.c:378 [inline] tcp_write_timer_handler net/ipv4/tcp_timer.c:624 [inline] tcp_write_timer_handler+0x998/0x9f0 net/ipv4/tcp_timer.c:594 tcp_write_timer+0xa2/0x2b0 net/ipv4/tcp_timer.c:637 call_timer_fn+0x1a0/0x6b0 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1519 [inline] __run_timers.part.0+0x674/0xa80 kernel/time/timer.c:1790 __run_timers kernel/time/timer.c:1768 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1803 __do_softirq+0x1d0/0x9c8 kernel/softirq.c:571 invoke_softirq kernel/softirq.c:445 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:650 irq_exit_rcu+0x5/0x20 kernel/softirq.c:662 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1107 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:166 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:200 Code: 48 89 ef 5d e9 a1 6b 4c 00 5d be 03 00 00 00 e9 b6 09 83 02 66 0f 1f 44 00 00 48 8b be a8 01 00 00 e8 b4 ff ff ff 31 c0 c3 90 <65> 8b 05 c9 59 87 7e 89 c1 48 8b 34 24 81 e1 00 01 00 00 65 48 8b RSP: 0018:ffffc9000550fc18 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000200 RCX: 0000000000000000 RDX: ffff88801b833b00 RSI: ffffffff814e0b55 RDI: 0000000000000007 RBP: ffff88804a007c00 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000200 R11: 000000000008c07c R12: 0000000000000000 R13: 0000000000000001 R14: ffff888011864c00 R15: 0000000000000000 queue_delayed_work_on+0xbb/0x120 kernel/workqueue.c:1706 queue_delayed_work include/linux/workqueue.h:518 [inline] schedule_delayed_work include/linux/workqueue.h:670 [inline] nsim_dev_trap_report_work+0x9c6/0xc50 drivers/net/netdevsim/dev.c:836 process_one_work+0x991/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 Allocated by task 3641: 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:437 [inline] __kasan_slab_alloc+0x90/0xc0 mm/kasan/common.c:470 kasan_slab_alloc include/linux/kasan.h:224 [inline] slab_post_alloc_hook mm/slab.h:727 [inline] slab_alloc_node mm/slub.c:3248 [inline] slab_alloc mm/slub.c:3256 [inline] __kmem_cache_alloc_lru mm/slub.c:3263 [inline] kmem_cache_alloc+0x267/0x3b0 mm/slub.c:3273 kmem_cache_zalloc include/linux/slab.h:723 [inline] net_alloc net/core/net_namespace.c:403 [inline] copy_net_ns+0x125/0x760 net/core/net_namespace.c:458 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:226 ksys_unshare+0x445/0x920 kernel/fork.c:3181 __do_sys_unshare kernel/fork.c:3252 [inline] __se_sys_unshare kernel/fork.c:3250 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3250 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+0x63/0xcd The buggy address belongs to the object at ffff88801e16b880 which belongs to the cache net_namespace of size 6976 The buggy address is located 1861 bytes inside of 6976-byte region [ffff88801e16b880, ffff88801e16d3c0) The buggy address belongs to the physical page: page:ffffea0000785a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88801e16b880 pfn:0x1e168 head:ffffea0000785a00 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff888077db08c1 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffff8880119d5288 ffffea0001f69e08 ffff8880119d43c0 raw: ffff88801e16b880 0000000000040002 00000001ffffffff ffff888077db08c1 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 3637, tgid 3637 (syz-executor.1), ts 132547331182, free_ts 132546050059 prep_new_page mm/page_alloc.c:2532 [inline] get_page_from_freelist+0x109b/0x2ce0 mm/page_alloc.c:4283 __alloc_pages+0x1c7/0x510 mm/page_alloc.c:5549 alloc_pages+0x1a6/0x270 mm/mempolicy.c:2270 alloc_slab_page mm/slub.c:1829 [inline] allocate_slab+0x27e/0x3d0 mm/slub.c:1974 new_slab mm/slub.c:2034 [inline] ___slab_alloc+0x84f/0xe80 mm/slub.c:3036 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3123 slab_alloc_node mm/slub.c:3214 [inline] slab_alloc mm/slub.c:3256 [inline] __kmem_cache_alloc_lru mm/slub.c:3263 [inline] kmem_cache_alloc+0x38c/0x3b0 mm/slub.c:3273 kmem_cache_zalloc include/linux/slab.h:723 [inline] net_alloc net/core/net_namespace.c:403 [inline] copy_net_ns+0x125/0x760 net/core/net_namespace.c:458 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:226 ksys_unshare+0x445/0x920 kernel/fork.c:3181 __do_sys_unshare kernel/fork.c:3252 [inline] __se_sys_unshare kernel/fork.c:3250 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3250 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+0x63/0xcd page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1449 [inline] free_pcp_prepare+0x5e4/0xd20 mm/page_alloc.c:1499 free_unref_page_prepare mm/page_alloc.c:3380 [inline] free_unref_page+0x19/0x4d0 mm/page_alloc.c:3476 skb_free_head+0xac/0x110 net/core/skbuff.c:760 skb_release_data+0x5f1/0x870 net/core/skbuff.c:789 skb_release_all net/core/skbuff.c:854 [inline] __kfree_skb net/core/skbuff.c:868 [inline] consume_skb net/core/skbuff.c:1033 [inline] consume_skb+0xc2/0x160 net/core/skbuff.c:1027 netlink_recvmsg+0x598/0xe50 net/netlink/af_netlink.c:1998 sock_recvmsg_nosec net/socket.c:995 [inline] sock_recvmsg net/socket.c:1013 [inline] sock_recvmsg net/socket.c:1009 [inline] ____sys_recvmsg+0x2c7/0x600 net/socket.c:2701 ___sys_recvmsg+0xf2/0x180 net/socket.c:2743 __sys_recvmsg+0xf0/0x1c0 net/socket.c:2773 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+0x63/0xcd Memory state around the buggy address: ffff88801e16be80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801e16bf00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88801e16bf80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801e16c000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801e16c080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 48 89 ef mov %rbp,%rdi 3: 5d pop %rbp 4: e9 a1 6b 4c 00 jmpq 0x4c6baa 9: 5d pop %rbp a: be 03 00 00 00 mov $0x3,%esi f: e9 b6 09 83 02 jmpq 0x28309ca 14: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) 1a: 48 8b be a8 01 00 00 mov 0x1a8(%rsi),%rdi 21: e8 b4 ff ff ff callq 0xffffffda 26: 31 c0 xor %eax,%eax 28: c3 retq 29: 90 nop * 2a: 65 8b 05 c9 59 87 7e mov %gs:0x7e8759c9(%rip),%eax # 0x7e8759fa <-- trapping instruction 31: 89 c1 mov %eax,%ecx 33: 48 8b 34 24 mov (%rsp),%rsi 37: 81 e1 00 01 00 00 and $0x100,%ecx 3d: 65 gs 3e: 48 rex.W 3f: 8b .byte 0x8b