================================================================== BUG: KASAN: use-after-free in tcp_probe_timer net/ipv4/tcp_timer.c:388 [inline] BUG: KASAN: use-after-free in tcp_write_timer_handler+0x7ef/0x930 net/ipv4/tcp_timer.c:652 Read of size 1 at addr ffff88807ae7dc05 by task swapper/0/0 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.1.82-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 print_address_description mm/kasan/report.c:284 [inline] print_report+0x15f/0x4f0 mm/kasan/report.c:395 kasan_report+0x136/0x160 mm/kasan/report.c:495 tcp_probe_timer net/ipv4/tcp_timer.c:388 [inline] tcp_write_timer_handler+0x7ef/0x930 net/ipv4/tcp_timer.c:652 tcp_write_timer+0x12e/0x280 net/ipv4/tcp_timer.c:665 call_timer_fn+0x1ad/0x6b0 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1519 [inline] __run_timers+0x67c/0x890 kernel/time/timer.c:1790 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1803 __do_softirq+0x2e9/0xa4c kernel/softirq.c:571 invoke_softirq kernel/softirq.c:445 [inline] __irq_exit_rcu+0x155/0x240 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:1106 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:22 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline] RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:130 [inline] RIP: 0010:acpi_safe_halt drivers/acpi/processor_idle.c:113 [inline] RIP: 0010:acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:572 Code: c6 f6 f6 48 83 e3 08 0f 85 0b 01 00 00 4c 8d 74 24 20 e8 84 82 fd f6 0f 1f 44 00 00 e8 2a c2 f6 f6 0f 00 2d 33 7b b3 00 fb f4 <4c> 89 f3 48 c1 eb 03 42 80 3c 3b 00 74 08 4c 89 f7 e8 ab 37 4e f7 RSP: 0018:ffffffff8ce07b20 EFLAGS: 000002d3 RAX: ffffffff8a93c166 RBX: 0000000000000000 RCX: ffffffff8cebd800 RDX: 0000000000000000 RSI: ffffffff8aebee40 RDI: ffffffff8b3d2b40 RBP: ffffffff8ce07bb0 R08: ffffffff8a93c148 R09: fffffbfff19d7b01 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffffffff19c0f64 R13: ffff888015bc9004 R14: ffffffff8ce07b40 R15: dffffc0000000000 acpi_idle_enter+0x352/0x4f0 drivers/acpi/processor_idle.c:709 cpuidle_enter_state+0x516/0xf80 drivers/cpuidle/cpuidle.c:239 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+0x3ce/0x680 kernel/sched/idle.c:303 cpu_startup_entry+0x3d/0x60 kernel/sched/idle.c:401 rest_init+0x2da/0x300 init/main.c:731 arch_call_rest_init+0xa/0xa init/main.c:891 start_kernel+0x496/0x53f init/main.c:1138 secondary_startup_64_no_verify+0xcf/0xdb Allocated by task 21083: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 __kasan_slab_alloc+0x65/0x70 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x52/0x3a0 mm/slab.h:737 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+0x10c/0x2d0 mm/slub.c:3422 kmem_cache_zalloc include/linux/slab.h:682 [inline] net_alloc net/core/net_namespace.c:410 [inline] copy_net_ns+0x143/0x5d0 net/core/net_namespace.c:465 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:3203 __do_sys_unshare kernel/fork.c:3274 [inline] __se_sys_unshare kernel/fork.c:3272 [inline] __x64_sys_unshare+0x34/0x40 kernel/fork.c:3272 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x63/0xcd The buggy address belongs to the object at ffff88807ae7d4c0 which belongs to the cache net_namespace of size 6976 The buggy address is located 1861 bytes inside of 6976-byte region [ffff88807ae7d4c0, ffff88807ae7f000) The buggy address belongs to the physical page: page:ffffea0001eb9e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88807ae7d4c0 pfn:0x7ae78 head:ffffea0001eb9e00 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff88803c9b8981 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000001 ffff888012626500 raw: ffff88807ae7d4c0 0000000080040003 00000001ffffffff ffff88803c9b8981 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 15031, tgid 15030 (syz-executor.1), ts 414870471937, free_ts 411825511498 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x18d/0x1b0 mm/page_alloc.c:2513 prep_new_page mm/page_alloc.c:2520 [inline] get_page_from_freelist+0x31a1/0x3320 mm/page_alloc.c:4279 __alloc_pages+0x28d/0x770 mm/page_alloc.c:5545 alloc_slab_page+0x6a/0x150 mm/slub.c:1794 allocate_slab mm/slub.c:1939 [inline] new_slab+0x84/0x2d0 mm/slub.c:1992 ___slab_alloc+0xc20/0x1270 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+0x1a5/0x2d0 mm/slub.c:3422 kmem_cache_zalloc include/linux/slab.h:682 [inline] net_alloc net/core/net_namespace.c:410 [inline] copy_net_ns+0x143/0x5d0 net/core/net_namespace.c:465 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:3203 __do_sys_unshare kernel/fork.c:3274 [inline] __se_sys_unshare kernel/fork.c:3272 [inline] __x64_sys_unshare+0x34/0x40 kernel/fork.c:3272 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81 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:1440 [inline] free_pcp_prepare mm/page_alloc.c:1490 [inline] free_unref_page_prepare+0xf63/0x1120 mm/page_alloc.c:3358 free_unref_page+0x33/0x3e0 mm/page_alloc.c:3453 __skb_frag_unref include/linux/skbuff.h:3404 [inline] skb_release_data+0x37f/0x7a0 net/core/skbuff.c:785 skb_release_all net/core/skbuff.c:856 [inline] __kfree_skb net/core/skbuff.c:870 [inline] skb_attempt_defer_free+0x29a/0x400 net/core/skbuff.c:6663 tcp_eat_recv_skb net/ipv4/tcp.c:1660 [inline] tcp_recvmsg_locked+0x1209/0x2450 net/ipv4/tcp.c:2654 tcp_recvmsg+0x258/0x920 net/ipv4/tcp.c:2700 inet_recvmsg+0x13b/0x250 net/ipv4/af_inet.c:888 ____sys_recvmsg+0x285/0x530 ___sys_recvmsg net/socket.c:2775 [inline] __sys_recvmsg+0x2e9/0x3d0 net/socket.c:2805 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x63/0xcd Memory state around the buggy address: ffff88807ae7db00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807ae7db80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807ae7dc00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807ae7dc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807ae7dd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess), 1 bytes skipped: 0: f6 f6 div %dh 2: 48 83 e3 08 and $0x8,%rbx 6: 0f 85 0b 01 00 00 jne 0x117 c: 4c 8d 74 24 20 lea 0x20(%rsp),%r14 11: e8 84 82 fd f6 call 0xf6fd829a 16: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 1b: e8 2a c2 f6 f6 call 0xf6f6c24a 20: 0f 00 2d 33 7b b3 00 verw 0xb37b33(%rip) # 0xb37b5a 27: fb sti 28: f4 hlt * 29: 4c 89 f3 mov %r14,%rbx <-- trapping instruction 2c: 48 c1 eb 03 shr $0x3,%rbx 30: 42 80 3c 3b 00 cmpb $0x0,(%rbx,%r15,1) 35: 74 08 je 0x3f 37: 4c 89 f7 mov %r14,%rdi 3a: e8 ab 37 4e f7 call 0xf74e37ea