================================================================== BUG: KASAN: use-after-free in tcp_retransmit_timer+0x6ee/0x2890 net/ipv4/tcp_timer.c:515 Read of size 8 at addr ffff88807e74b6d8 by task syz-executor.5/14237 CPU: 0 PID: 14237 Comm: syz-executor.5 Not tainted 5.15.105-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 print_address_description+0x63/0x3b0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0x16b/0x1c0 mm/kasan/report.c:451 tcp_retransmit_timer+0x6ee/0x2890 net/ipv4/tcp_timer.c:515 tcp_write_timer_handler+0x1f7/0x9c0 net/ipv4/tcp_timer.c:626 tcp_write_timer+0x12e/0x280 net/ipv4/tcp_timer.c:646 call_timer_fn+0x16d/0x560 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1466 [inline] __run_timers+0x67c/0x890 kernel/time/timer.c:1737 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1750 __do_softirq+0x3b3/0x93a kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x155/0x240 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:zap_pmd_range mm/memory.c:1494 [inline] RIP: 0010:zap_pud_range mm/memory.c:1523 [inline] RIP: 0010:zap_p4d_range mm/memory.c:1544 [inline] RIP: 0010:unmap_page_range+0xdd8/0x2630 mm/memory.c:1565 Code: 11 e8 2c 73 c8 ff eb 22 e8 25 73 c8 ff e9 8f 00 00 00 e8 1b 73 c8 ff 4c 89 ef e8 a3 ec f2 ff c7 84 24 94 00 00 00 01 00 00 00 <48> 8b 5c 24 40 89 de 83 e6 20 31 ff e8 57 76 c8 ff 89 d8 83 e0 20 RSP: 0018:ffffc9000342f420 EFLAGS: 00000293 RAX: ffffffff81b74794 RBX: 800000005fa00007 RCX: ffff888023369d00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000342f650 R08: ffffffff81b74788 R09: ffffed100466d3a1 R10: 0000000000000000 R11: dffffc0000000001 R12: 00007fc4f1282000 R13: ffffea00017e8000 R14: ffffea00017e8008 R15: dffffc0000000000 unmap_vmas+0x1f8/0x390 mm/memory.c:1642 exit_mmap+0x3b6/0x670 mm/mmap.c:3186 __mmput+0x112/0x3b0 kernel/fork.c:1118 exit_mm+0x688/0x7f0 kernel/exit.c:548 do_exit+0x626/0x2480 kernel/exit.c:859 do_group_exit+0x144/0x310 kernel/exit.c:994 get_signal+0xc66/0x14e0 kernel/signal.c:2889 arch_do_signal_or_restart+0xc3/0x1890 arch/x86/kernel/signal.c:865 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop+0x97/0x130 kernel/entry/common.c:172 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:208 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] syscall_exit_to_user_mode+0x5d/0x250 kernel/entry/common.c:301 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7fc4f2371169 Code: Unable to access opcode bytes at RIP 0x7fc4f237113f. RSP: 002b:00007fc4f08e3168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: 0000000000070000 RBX: 00007fc4f2490f80 RCX: 00007fc4f2371169 RDX: 0000000000020030 RSI: 0000000020000a80 RDI: 0000000000000003 RBP: 00007fc4f23ccca1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd80cd5baf R14: 00007fc4f08e3300 R15: 0000000000022000 Allocated by task 3612: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] __kasan_slab_alloc+0x8e/0xc0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x53/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3220 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc+0xf3/0x280 mm/slub.c:3233 kmem_cache_zalloc include/linux/slab.h:711 [inline] net_alloc net/core/net_namespace.c:405 [inline] copy_net_ns+0x143/0x5d0 net/core/net_namespace.c:460 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:3094 __do_sys_unshare kernel/fork.c:3168 [inline] __se_sys_unshare kernel/fork.c:3166 [inline] __x64_sys_unshare+0x34/0x40 kernel/fork.c:3166 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb The buggy address belongs to the object at ffff88807e74b480 which belongs to the cache net_namespace of size 6464 The buggy address is located 600 bytes inside of 6464-byte region [ffff88807e74b480, ffff88807e74cdc0) The buggy address belongs to the page: page:ffffea0001f9d200 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88807e74b480 pfn:0x7e748 head:ffffea0001f9d200 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0001e1cc00 0000000200000002 ffff888011dc63c0 raw: ffff88807e74b480 0000000080040000 00000001ffffffff 0000000000000000 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 3606, ts 64272660438, free_ts 64269372378 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x322a/0x33c0 mm/page_alloc.c:4159 __alloc_pages+0x272/0x700 mm/page_alloc.c:5421 alloc_slab_page mm/slub.c:1775 [inline] allocate_slab mm/slub.c:1912 [inline] new_slab+0xbb/0x4b0 mm/slub.c:1975 ___slab_alloc+0x6f6/0xe10 mm/slub.c:3008 __slab_alloc mm/slub.c:3095 [inline] slab_alloc_node mm/slub.c:3186 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc+0x18e/0x280 mm/slub.c:3233 kmem_cache_zalloc include/linux/slab.h:711 [inline] net_alloc net/core/net_namespace.c:405 [inline] copy_net_ns+0x143/0x5d0 net/core/net_namespace.c:460 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:3094 __do_sys_unshare kernel/fork.c:3168 [inline] __se_sys_unshare kernel/fork.c:3166 [inline] __x64_sys_unshare+0x34/0x40 kernel/fork.c:3166 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0xc34/0xcf0 mm/page_alloc.c:3317 free_unref_page+0x95/0x2d0 mm/page_alloc.c:3396 free_nonslab_page+0xe4/0x150 mm/slub.c:3535 kfree+0x1cf/0x270 mm/slub.c:4556 skb_free_head net/core/skbuff.c:655 [inline] skb_release_data+0x73a/0x8a0 net/core/skbuff.c:677 skb_release_all net/core/skbuff.c:742 [inline] __kfree_skb net/core/skbuff.c:756 [inline] consume_skb+0xa3/0x140 net/core/skbuff.c:914 skb_free_datagram+0x24/0xe0 net/core/datagram.c:325 netlink_recvmsg+0x5ef/0x1140 net/netlink/af_netlink.c:2030 ____sys_recvmsg+0x286/0x530 ___sys_recvmsg+0x1ec/0x690 net/socket.c:2673 __sys_recvmsg net/socket.c:2703 [inline] __do_sys_recvmsg net/socket.c:2713 [inline] __se_sys_recvmsg net/socket.c:2710 [inline] __x64_sys_recvmsg+0x1dc/0x2b0 net/socket.c:2710 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb Memory state around the buggy address: ffff88807e74b580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807e74b600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807e74b680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807e74b700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807e74b780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 11 e8 adc %ebp,%eax 2: 2c 73 sub $0x73,%al 4: c8 ff eb 22 enterq $0xebff,$0x22 8: e8 25 73 c8 ff callq 0xffc87332 d: e9 8f 00 00 00 jmpq 0xa1 12: e8 1b 73 c8 ff callq 0xffc87332 17: 4c 89 ef mov %r13,%rdi 1a: e8 a3 ec f2 ff callq 0xfff2ecc2 1f: c7 84 24 94 00 00 00 movl $0x1,0x94(%rsp) 26: 01 00 00 00 * 2a: 48 8b 5c 24 40 mov 0x40(%rsp),%rbx <-- trapping instruction 2f: 89 de mov %ebx,%esi 31: 83 e6 20 and $0x20,%esi 34: 31 ff xor %edi,%edi 36: e8 57 76 c8 ff callq 0xffc87692 3b: 89 d8 mov %ebx,%eax 3d: 83 e0 20 and $0x20,%eax