================================================================== BUG: KASAN: use-after-free in tcp_retransmit_timer+0x6ee/0x2890 net/ipv4/tcp_timer.c:515 Read of size 8 at addr ffff88807e839c98 by task syz-executor.5/6597 CPU: 0 PID: 6597 Comm: syz-executor.5 Not tainted 5.15.110-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 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:PagePoisoned include/linux/page-flags.h:218 [inline] RIP: 0010:PageSwapBacked include/linux/page-flags.h:371 [inline] RIP: 0010:mm_counter_file include/linux/mm.h:1966 [inline] RIP: 0010:mm_counter include/linux/mm.h:1975 [inline] RIP: 0010:zap_pte_range mm/memory.c:1372 [inline] 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+0xeff/0x2630 mm/memory.c:1565 Code: 48 89 de 48 83 e6 01 31 ff e8 8d 6d c8 ff 48 89 d8 48 83 e0 01 0f 85 4e 0b 00 00 e8 9b 69 c8 ff 4c 89 eb 48 89 d8 48 c1 e8 03 <42> 80 3c 38 00 74 08 48 89 df e8 b2 c3 11 00 4c 89 64 24 08 48 8b RSP: 0018:ffffc90002f6f420 EFLAGS: 00000a06 RAX: 1ffffd40002d7ed8 RBX: ffffea00016bf6c0 RCX: ffff888059430000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90002f6f650 R08: ffffffff81b774d3 R09: ffffed100b286001 R10: 0000000000000000 R11: dffffc0000000001 R12: 00007fea0201c000 R13: ffffea00016bf6c0 R14: ffffea00016bf6c8 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: 0033:0x7fea02b6f169 Code: Unable to access opcode bytes at RIP 0x7fea02b6f13f. RSP: 002b:00007fea010e1218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007fea02c8ef88 RCX: 00007fea02b6f169 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fea02c8ef88 RBP: 00007fea02c8ef80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fea02c8ef8c R13: 00007fff4c9974bf R14: 00007fea010e1300 R15: 0000000000022000 Allocated by task 3526: 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 Freed by task 154: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x80 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd8/0x120 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1705 [inline] slab_free_freelist_hook+0xdd/0x160 mm/slub.c:1731 slab_free mm/slub.c:3499 [inline] kmem_cache_free+0x91/0x1f0 mm/slub.c:3515 net_free net/core/net_namespace.c:434 [inline] cleanup_net+0xab5/0xb60 net/core/net_namespace.c:617 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2306 worker_thread+0xaca/0x1280 kernel/workqueue.c:2453 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 The buggy address belongs to the object at ffff88807e839a40 which belongs to the cache net_namespace of size 6464 The buggy address is located 600 bytes inside of 6464-byte region [ffff88807e839a40, ffff88807e83b380) The buggy address belongs to the page: page:ffffea0001fa0e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7e838 head:ffffea0001fa0e00 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000122 ffff8881400043c0 raw: 0000000000000000 0000000000040004 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 3519, ts 88763559260, free_ts 88761620817 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 do_slab_free mm/slub.c:3487 [inline] ___cache_free+0xe3/0x100 mm/slub.c:3506 qlist_free_all+0x36/0x90 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x162/0x180 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xc0 mm/kasan/common.c:444 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] kmem_cache_alloc_node+0x121/0x2c0 mm/slub.c:3256 __alloc_skb+0xdd/0x590 net/core/skbuff.c:415 alloc_skb include/linux/skbuff.h:1167 [inline] netlink_alloc_large_skb net/netlink/af_netlink.c:1202 [inline] netlink_sendmsg+0x6f8/0xd60 net/netlink/af_netlink.c:1927 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg net/socket.c:724 [inline] ____sys_sendmsg+0x59e/0x8f0 net/socket.c:2412 ___sys_sendmsg+0x252/0x2e0 net/socket.c:2466 __sys_sendmsg net/socket.c:2495 [inline] __do_sys_sendmsg net/socket.c:2504 [inline] __se_sys_sendmsg+0x19a/0x260 net/socket.c:2502 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: ffff88807e839b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807e839c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807e839c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807e839d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807e839d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 48 89 de mov %rbx,%rsi 3: 48 83 e6 01 and $0x1,%rsi 7: 31 ff xor %edi,%edi 9: e8 8d 6d c8 ff callq 0xffc86d9b e: 48 89 d8 mov %rbx,%rax 11: 48 83 e0 01 and $0x1,%rax 15: 0f 85 4e 0b 00 00 jne 0xb69 1b: e8 9b 69 c8 ff callq 0xffc869bb 20: 4c 89 eb mov %r13,%rbx 23: 48 89 d8 mov %rbx,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 42 80 3c 38 00 cmpb $0x0,(%rax,%r15,1) <-- trapping instruction 2f: 74 08 je 0x39 31: 48 89 df mov %rbx,%rdi 34: e8 b2 c3 11 00 callq 0x11c3eb 39: 4c 89 64 24 08 mov %r12,0x8(%rsp) 3e: 48 rex.W 3f: 8b .byte 0x8b