================================================================== BUG: KASAN: use-after-free in tcp_retransmit_timer+0x6ee/0x2890 net/ipv4/tcp_timer.c:515 Read of size 8 at addr ffff88807d151c98 by task udevd/2963 CPU: 0 PID: 2963 Comm: udevd Not tainted 5.15.112-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023 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:1096 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:filter_irq_stacks+0x4b/0xa0 kernel/stacktrace.c:398 Code: 00 00 60 8a 48 89 fb eb 0c 49 ff c7 48 83 c3 08 4d 39 fc 74 4f 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 <74> 08 48 89 df e8 5b 90 5b 00 4b 8b 04 fe 48 39 e8 72 0c 48 c7 c1 RSP: 0018:ffffc90002c3f208 EFLAGS: 00000246 RAX: 1ffff92000587e55 RBX: ffffc90002c3f2a8 RCX: dffffc0000000000 RDX: 0000000000000001 RSI: 000000000000000f RDI: ffffc90002c3f240 RBP: ffffffff8a400190 R08: dffffc0000000000 R09: fffffbfff1bc7636 R10: 0000000000000000 R11: dffffc0000000001 R12: 000000000000000f R13: ffffffff8a600000 R14: ffffc90002c3f240 R15: 000000000000000d kasan_save_stack mm/kasan/common.c:39 [inline] kasan_set_track+0x55/0x80 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] kfree+0xf1/0x270 mm/slub.c:4559 tomoyo_realpath_from_path+0x5ad/0x5e0 security/tomoyo/realpath.c:291 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_check_open_permission+0x22c/0x490 security/tomoyo/file.c:771 security_file_open+0x5f/0xa0 security/security.c:1650 do_dentry_open+0x315/0xfb0 fs/open.c:813 do_open fs/namei.c:3538 [inline] path_openat+0x2702/0x2f20 fs/namei.c:3672 do_filp_open+0x21c/0x460 fs/namei.c:3699 do_sys_openat2+0x13b/0x500 fs/open.c:1211 do_sys_open fs/open.c:1227 [inline] __do_sys_openat fs/open.c:1243 [inline] __se_sys_openat fs/open.c:1238 [inline] __x64_sys_openat+0x243/0x290 fs/open.c:1238 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 RIP: 0033:0x7f0a2ba9e9a4 Code: 24 20 48 8d 44 24 30 48 89 44 24 28 64 8b 04 25 18 00 00 00 85 c0 75 2c 44 89 e2 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 76 60 48 8b 15 55 a4 0d 00 f7 d8 64 89 02 48 83 RSP: 002b:00007ffdd00a02f0 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000008 RCX: 00007f0a2ba9e9a4 RDX: 0000000000080000 RSI: 00007ffdd00a0428 RDI: 00000000ffffff9c RBP: 00007ffdd00a0428 R08: 0000000000000008 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000080000 R13: 00005627e2802b42 R14: 0000000000000001 R15: 0000000000000000 Allocated by task 3536: 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 936: 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:2307 worker_thread+0xaca/0x1280 kernel/workqueue.c:2454 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 ffff88807d151a40 which belongs to the cache net_namespace of size 6464 The buggy address is located 600 bytes inside of 6464-byte region [ffff88807d151a40, ffff88807d153380) The buggy address belongs to the page: page:ffffea0001f45400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7d150 head:ffffea0001f45400 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff88802108fa01 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0001d98400 0000000300000003 ffff888011dc63c0 raw: 0000000000000000 0000000000040004 00000001ffffffff ffff88802108fa01 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 3532, ts 108554275348, free_ts 108553021156 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/0x1190 net/netlink/af_netlink.c:2001 ____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: ffff88807d151b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807d151c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807d151c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807d151d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807d151d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 00 60 8a add %ah,-0x76(%rax) 3: 48 89 fb mov %rdi,%rbx 6: eb 0c jmp 0x14 8: 49 ff c7 inc %r15 b: 48 83 c3 08 add $0x8,%rbx f: 4d 39 fc cmp %r15,%r12 12: 74 4f je 0x63 14: 48 89 d8 mov %rbx,%rax 17: 48 c1 e8 03 shr $0x3,%rax 1b: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx 22: fc ff df 25: 80 3c 08 00 cmpb $0x0,(%rax,%rcx,1) * 29: 74 08 je 0x33 <-- trapping instruction 2b: 48 89 df mov %rbx,%rdi 2e: e8 5b 90 5b 00 callq 0x5b908e 33: 4b 8b 04 fe mov (%r14,%r15,8),%rax 37: 48 39 e8 cmp %rbp,%rax 3a: 72 0c jb 0x48 3c: 48 rex.W 3d: c7 .byte 0xc7 3e: c1 .byte 0xc1