================================================================== 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+0x7e2/0x920 net/ipv4/tcp_timer.c:624 Read of size 1 at addr ffff888078a43fc5 by task swapper/1/0 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.1.0-rc1-syzkaller-00427-gd47136c28015 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 print_address_description+0x74/0x340 mm/kasan/report.c:284 print_report+0x107/0x220 mm/kasan/report.c:395 kasan_report+0x139/0x170 mm/kasan/report.c:495 tcp_probe_timer net/ipv4/tcp_timer.c:378 [inline] tcp_write_timer_handler+0x7e2/0x920 net/ipv4/tcp_timer.c:624 tcp_write_timer+0x176/0x280 net/ipv4/tcp_timer.c:637 call_timer_fn+0xf5/0x210 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1519 [inline] __run_timers+0x76a/0x980 kernel/time/timer.c:1790 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1803 __do_softirq+0x277/0x75b kernel/softirq.c:571 __irq_exit_rcu+0xec/0x170 kernel/softirq.c:650 irq_exit_rcu+0x5/0x20 kernel/softirq.c:662 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1107 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:cpuidle_enter_state+0x620/0xf50 drivers/cpuidle/cpuidle.c:261 Code: ea 1b fa 4c 21 f3 0f 85 b0 05 00 00 e8 79 e5 1b fa 31 ff e8 e2 a8 0e fa eb 05 e8 6b e5 1b fa e8 26 a9 22 fa fb bf ff ff ff ff <44> 89 fe e8 78 e9 1b fa 45 85 ff 0f 88 9a 01 00 00 44 89 fb bf 0a RSP: 0018:ffffc90000177ca0 EFLAGS: 00000286 RAX: b2b6f2b2198ef200 RBX: 0000000000000000 RCX: ffff888012391d40 RDX: dffffc0000000000 RSI: 0000000000000000 RDI: 00000000ffffffff RBP: ffffc90000177db0 R08: ffffffff876dbf18 R09: fffffbfff1c4f036 R10: fffffbfff1c4f036 R11: 1ffffffff1c4f035 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffff8d4050e0 R15: 0000000000000001 cpuidle_enter+0x59/0x90 drivers/cpuidle/cpuidle.c:356 call_cpuidle kernel/sched/idle.c:155 [inline] cpuidle_idle_call kernel/sched/idle.c:236 [inline] do_idle+0x3da/0x680 kernel/sched/idle.c:303 cpu_startup_entry+0x15/0x20 kernel/sched/idle.c:400 start_secondary+0xe4/0xf0 arch/x86/kernel/smpboot.c:262 secondary_startup_64_no_verify+0xcf/0xdb Allocated by task 8207: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4c/0x70 mm/kasan/common.c:52 __kasan_slab_alloc+0x65/0x70 mm/kasan/common.c:325 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slab.h:737 [inline] slab_alloc_node mm/slub.c:3398 [inline] slab_alloc mm/slub.c:3406 [inline] __kmem_cache_alloc_lru mm/slub.c:3413 [inline] kmem_cache_alloc+0x1cc/0x300 mm/slub.c:3422 kmem_cache_zalloc include/linux/slab.h:702 [inline] net_alloc net/core/net_namespace.c:403 [inline] copy_net_ns+0x13c/0x5b0 net/core/net_namespace.c:458 create_new_namespaces+0x4db/0x8e0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x11e/0x180 kernel/nsproxy.c:226 ksys_unshare+0x57f/0xb30 kernel/fork.c:3188 __do_sys_unshare kernel/fork.c:3259 [inline] __se_sys_unshare kernel/fork.c:3257 [inline] __x64_sys_unshare+0x34/0x40 kernel/fork.c:3257 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 4231: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4c/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:511 ____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1724 [inline] slab_free_freelist_hook+0x12e/0x1a0 mm/slub.c:1750 slab_free mm/slub.c:3661 [inline] kmem_cache_free+0x94/0x1d0 mm/slub.c:3683 net_free net/core/net_namespace.c:432 [inline] cleanup_net+0xb8b/0xc50 net/core/net_namespace.c:615 process_one_work+0x81c/0xd10 kernel/workqueue.c:2289 worker_thread+0xb14/0x1330 kernel/workqueue.c:2436 kthread+0x266/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 The buggy address belongs to the object at ffff888078a43880 which belongs to the cache net_namespace of size 6976 The buggy address is located 1861 bytes inside of 6976-byte region [ffff888078a43880, ffff888078a453c0) The buggy address belongs to the physical page: page:ffffea0001e29000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x78a40 head:ffffea0001e29000 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff88807ce90701 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000001 ffff8880121d5640 raw: 0000000000000000 0000000080040004 00000001ffffffff ffff88807ce90701 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 3639, tgid 3639 (syz-executor.5), ts 328263763316, free_ts 328237734982 prep_new_page mm/page_alloc.c:2538 [inline] get_page_from_freelist+0x72b/0x7a0 mm/page_alloc.c:4287 __alloc_pages+0x259/0x560 mm/page_alloc.c:5554 alloc_slab_page+0x70/0xf0 mm/slub.c:1794 allocate_slab+0x5e/0x4b0 mm/slub.c:1939 new_slab mm/slub.c:1992 [inline] ___slab_alloc+0x7f4/0xeb0 mm/slub.c:3180 __slab_alloc mm/slub.c:3279 [inline] slab_alloc_node mm/slub.c:3364 [inline] slab_alloc mm/slub.c:3406 [inline] __kmem_cache_alloc_lru mm/slub.c:3413 [inline] kmem_cache_alloc+0x24c/0x300 mm/slub.c:3422 kmem_cache_zalloc include/linux/slab.h:702 [inline] net_alloc net/core/net_namespace.c:403 [inline] copy_net_ns+0x13c/0x5b0 net/core/net_namespace.c:458 create_new_namespaces+0x4db/0x8e0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x11e/0x180 kernel/nsproxy.c:226 ksys_unshare+0x57f/0xb30 kernel/fork.c:3188 __do_sys_unshare kernel/fork.c:3259 [inline] __se_sys_unshare kernel/fork.c:3257 [inline] __x64_sys_unshare+0x34/0x40 kernel/fork.c:3257 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 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:1458 [inline] free_pcp_prepare+0x80c/0x8f0 mm/page_alloc.c:1508 free_unref_page_prepare mm/page_alloc.c:3386 [inline] free_unref_page+0x7d/0x630 mm/page_alloc.c:3482 free_slab mm/slub.c:2031 [inline] discard_slab mm/slub.c:2037 [inline] __unfreeze_partials+0x1ab/0x200 mm/slub.c:2586 put_cpu_partial+0x116/0x180 mm/slub.c:2662 qlist_free_all+0x2b/0x70 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x169/0x180 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x1f/0x70 mm/kasan/common.c:302 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slab.h:737 [inline] slab_alloc_node mm/slub.c:3398 [inline] __kmem_cache_alloc_node+0x1d7/0x310 mm/slub.c:3437 __do_kmalloc_node mm/slab_common.c:954 [inline] __kmalloc_node+0x9e/0x190 mm/slab_common.c:962 kmalloc_node include/linux/slab.h:602 [inline] kvmalloc_node+0x6e/0x180 mm/util.c:581 kvmalloc include/linux/slab.h:729 [inline] kvzalloc include/linux/slab.h:737 [inline] proc_sys_call_handler+0x3d5/0x880 fs/proc/proc_sysctl.c:587 call_write_iter include/linux/fs.h:2191 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x7b5/0xbb0 fs/read_write.c:584 ksys_write+0x19b/0x2c0 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Memory state around the buggy address: ffff888078a43e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888078a43f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888078a43f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888078a44000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888078a44080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 1b fa sbb %edx,%edi 2: 4c 21 f3 and %r14,%rbx 5: 0f 85 b0 05 00 00 jne 0x5bb b: e8 79 e5 1b fa callq 0xfa1be589 10: 31 ff xor %edi,%edi 12: e8 e2 a8 0e fa callq 0xfa0ea8f9 17: eb 05 jmp 0x1e 19: e8 6b e5 1b fa callq 0xfa1be589 1e: e8 26 a9 22 fa callq 0xfa22a949 23: fb sti 24: bf ff ff ff ff mov $0xffffffff,%edi * 29: 44 89 fe mov %r15d,%esi <-- trapping instruction 2c: e8 78 e9 1b fa callq 0xfa1be9a9 31: 45 85 ff test %r15d,%r15d 34: 0f 88 9a 01 00 00 js 0x1d4 3a: 44 89 fb mov %r15d,%ebx 3d: bf .byte 0xbf 3e: 0a .byte 0xa