================================================================== BUG: KASAN: use-after-free in tcp_probe_timer net/ipv4/tcp_timer.c:377 [inline] BUG: KASAN: use-after-free in tcp_write_timer_handler net/ipv4/tcp_timer.c:620 [inline] BUG: KASAN: use-after-free in tcp_write_timer_handler+0x998/0x9f0 net/ipv4/tcp_timer.c:590 Read of size 1 at addr ffff888073043da5 by task kworker/u4:0/29458 CPU: 0 PID: 29458 Comm: kworker/u4:0 Not tainted 5.19.0-rc4-syzkaller-00843-g7e40e16e38ba #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 Workqueue: bat_events batadv_tt_purge Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0xeb/0x495 mm/kasan/report.c:313 print_report mm/kasan/report.c:429 [inline] kasan_report.cold+0xf4/0x1c6 mm/kasan/report.c:491 tcp_probe_timer net/ipv4/tcp_timer.c:377 [inline] tcp_write_timer_handler net/ipv4/tcp_timer.c:620 [inline] tcp_write_timer_handler+0x998/0x9f0 net/ipv4/tcp_timer.c:590 tcp_write_timer+0xa2/0x2b0 net/ipv4/tcp_timer.c:633 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1519 [inline] __run_timers.part.0+0x679/0xa80 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+0x29b/0x9c2 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:1106 asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:__local_bh_enable_ip+0xa8/0x120 kernel/softirq.c:403 Code: 1d fd 20 ba 7e 65 8b 05 f6 20 ba 7e a9 00 ff ff 00 74 45 bf 01 00 00 00 e8 55 90 09 00 e8 20 6b 38 00 fb 65 8b 05 d8 20 ba 7e <85> c0 74 58 5b 5d c3 65 8b 05 c6 27 ba 7e 85 c0 75 a2 0f 0b eb 9e RSP: 0018:ffffc9001b377c00 EFLAGS: 00000206 RAX: 0000000080000000 RBX: 00000000fffffe00 RCX: 1ffffffff20daf96 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffffff8913b025 R08: 0000000000000001 R09: ffffffff9067a9f7 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000100 R13: ffff88805903e418 R14: 0000000000000238 R15: dffffc0000000000 spin_unlock_bh include/linux/spinlock.h:394 [inline] batadv_tt_local_purge+0x285/0x370 net/batman-adv/translation-table.c:1357 batadv_tt_purge+0x2c/0xaf0 net/batman-adv/translation-table.c:3561 process_one_work+0x996/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302 Allocated by task 3636: 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:436 [inline] __kasan_slab_alloc+0x90/0xc0 mm/kasan/common.c:469 kasan_slab_alloc include/linux/kasan.h:224 [inline] slab_post_alloc_hook mm/slab.h:750 [inline] slab_alloc_node mm/slub.c:3243 [inline] slab_alloc mm/slub.c:3251 [inline] __kmem_cache_alloc_lru mm/slub.c:3258 [inline] kmem_cache_alloc+0x204/0x3b0 mm/slub.c:3268 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:3165 __do_sys_unshare kernel/fork.c:3236 [inline] __se_sys_unshare kernel/fork.c:3234 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3234 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+0x46/0xb0 Last potentially related work creation: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 __kasan_record_aux_stack+0xbe/0xd0 mm/kasan/generic.c:348 insert_work+0x48/0x350 kernel/workqueue.c:1358 __queue_work+0x62f/0x1150 kernel/workqueue.c:1517 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1514 [inline] __run_timers.part.0+0x4a3/0xa80 kernel/time/timer.c:1790 __run_timers kernel/time/timer.c:1768 [inline] run_timer_softirq+0x152/0x1d0 kernel/time/timer.c:1805 __do_softirq+0x29b/0x9c2 kernel/softirq.c:571 Second to last potentially related work creation: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 __kasan_record_aux_stack+0xbe/0xd0 mm/kasan/generic.c:348 insert_work+0x48/0x350 kernel/workqueue.c:1358 __queue_work+0x62f/0x1150 kernel/workqueue.c:1517 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1514 [inline] __run_timers.part.0+0x4a3/0xa80 kernel/time/timer.c:1790 __run_timers kernel/time/timer.c:1768 [inline] run_timer_softirq+0x152/0x1d0 kernel/time/timer.c:1805 __do_softirq+0x29b/0x9c2 kernel/softirq.c:571 The buggy address belongs to the object at ffff888073043700 which belongs to the cache net_namespace of size 6784 The buggy address is located 1701 bytes inside of 6784-byte region [ffff888073043700, ffff888073045180) The buggy address belongs to the physical page: page:ffffea0001cc1000 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888073043700 pfn:0x73040 head:ffffea0001cc1000 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff88801d5d1a41 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0001b77000 dead000000000003 ffff8881400073c0 raw: ffff888073043700 0000000080040002 00000001ffffffff ffff88801d5d1a41 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 3634, tgid 3634 (syz-executor.0), ts 130055788553, free_ts 91516097399 prep_new_page mm/page_alloc.c:2456 [inline] get_page_from_freelist+0x1290/0x3b70 mm/page_alloc.c:4198 __alloc_pages+0x1c7/0x510 mm/page_alloc.c:5426 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2272 alloc_slab_page mm/slub.c:1824 [inline] allocate_slab+0x26c/0x3c0 mm/slub.c:1969 new_slab mm/slub.c:2029 [inline] ___slab_alloc+0x9c4/0xe20 mm/slub.c:3031 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3118 slab_alloc_node mm/slub.c:3209 [inline] slab_alloc mm/slub.c:3251 [inline] __kmem_cache_alloc_lru mm/slub.c:3258 [inline] kmem_cache_alloc+0x360/0x3b0 mm/slub.c:3268 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:3165 __do_sys_unshare kernel/fork.c:3236 [inline] __se_sys_unshare kernel/fork.c:3234 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3234 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+0x46/0xb0 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1371 [inline] free_pcp_prepare+0x549/0xd20 mm/page_alloc.c:1421 free_unref_page_prepare mm/page_alloc.c:3343 [inline] free_unref_page+0x19/0x6a0 mm/page_alloc.c:3438 __unfreeze_partials+0x17c/0x1a0 mm/slub.c:2548 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0xa2/0xc0 mm/kasan/common.c:446 kasan_slab_alloc include/linux/kasan.h:224 [inline] slab_post_alloc_hook mm/slab.h:750 [inline] slab_alloc_node mm/slub.c:3243 [inline] kmem_cache_alloc_node+0x255/0x3f0 mm/slub.c:3293 __alloc_skb+0x215/0x340 net/core/skbuff.c:418 alloc_skb_fclone include/linux/skbuff.h:1299 [inline] tcp_stream_alloc_skb+0x38/0x580 net/ipv4/tcp.c:861 tcp_sendmsg_locked+0xad1/0x2e90 net/ipv4/tcp.c:1318 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1473 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:819 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:734 sock_write_iter+0x284/0x3c0 net/socket.c:1108 call_write_iter include/linux/fs.h:2058 [inline] new_sync_write+0x38a/0x560 fs/read_write.c:504 vfs_write+0x7c0/0xac0 fs/read_write.c:591 Memory state around the buggy address: ffff888073043c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888073043d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888073043d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888073043e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888073043e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 1d fd 20 ba 7e sbb $0x7eba20fd,%eax 5: 65 8b 05 f6 20 ba 7e mov %gs:0x7eba20f6(%rip),%eax # 0x7eba2102 c: a9 00 ff ff 00 test $0xffff00,%eax 11: 74 45 je 0x58 13: bf 01 00 00 00 mov $0x1,%edi 18: e8 55 90 09 00 callq 0x99072 1d: e8 20 6b 38 00 callq 0x386b42 22: fb sti 23: 65 8b 05 d8 20 ba 7e mov %gs:0x7eba20d8(%rip),%eax # 0x7eba2102 * 2a: 85 c0 test %eax,%eax <-- trapping instruction 2c: 74 58 je 0x86 2e: 5b pop %rbx 2f: 5d pop %rbp 30: c3 retq 31: 65 8b 05 c6 27 ba 7e mov %gs:0x7eba27c6(%rip),%eax # 0x7eba27fe 38: 85 c0 test %eax,%eax 3a: 75 a2 jne 0xffffffde 3c: 0f 0b ud2 3e: eb 9e jmp 0xffffffde