================================================================== 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+0x7ef/0x930 net/ipv4/tcp_timer.c:624 Read of size 1 at addr ffff88804927dc05 by task syz-executor.3/12696 CPU: 1 PID: 12696 Comm: syz-executor.3 Not tainted 6.1.15-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023 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:378 [inline] tcp_write_timer_handler+0x7ef/0x930 net/ipv4/tcp_timer.c:624 tcp_write_timer+0x12e/0x280 net/ipv4/tcp_timer.c:637 call_timer_fn+0x1e5/0x800 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+0x304/0xb09 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:1107 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:finish_lock_switch+0x91/0x100 kernel/sched/core.c:4998 Code: 45 31 c9 68 e7 67 60 81 e8 1c b5 09 00 48 83 c4 08 4c 89 ff e8 e0 cb fe ff 66 90 4c 89 ff e8 76 7d 2a 09 e8 a1 74 30 00 fb 5b <41> 5c 41 5d 41 5e 41 5f c3 44 89 f1 80 e1 07 80 c1 03 38 c1 7c 87 RSP: 0000:ffffc9000a3c7c98 EFLAGS: 00000286 RAX: 6851f8b72ac25c00 RBX: ffff8880558a1d74 RCX: ffffffff9196d003 RDX: dffffc0000000000 RSI: ffffffff8aebcf60 RDI: ffffffff8b3d0400 RBP: ffffc9000a3c7d10 R08: dffffc0000000000 R09: ffffed10173673b9 R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000 R13: 1ffff11017367563 R14: ffff8880b9b3ab18 R15: ffff8880b9b39dc0 finish_task_switch+0x134/0x630 kernel/sched/core.c:5115 context_switch kernel/sched/core.c:5241 [inline] __schedule+0x137e/0x4360 kernel/sched/core.c:6551 schedule+0xbf/0x180 kernel/sched/core.c:6627 exit_to_user_mode_loop+0x44/0x100 kernel/entry/common.c:159 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:203 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:309 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:654 RIP: 0033:0x7f40cfe393b6 Code: 1f 44 00 00 4c 89 ff e8 38 08 ff ff 41 08 c5 0f 85 f7 01 00 00 41 83 c6 01 44 39 73 04 0f 86 b7 00 00 00 48 8b 04 24 44 89 f7 <48> 8b 53 28 4d 89 f8 48 03 14 f8 80 3d f0 ec 16 00 00 49 89 d7 89 RSP: 002b:00007ffe386580d0 EFLAGS: 00000216 RAX: 00007f40cf400008 RBX: 00007f40cffac1b8 RCX: 0000001b30c20000 RDX: 0000000067cadaff RSI: 0000001b30c36c84 RDI: 00000000000232eb RBP: 0000000067cadaff R08: 0000000000001aff R09: 0000000067cadb03 R10: 00007ffe38658290 R11: 0000000000000246 R12: 00007f40cffa0000 R13: 0000000000000001 R14: 00000000000232eb R15: ffffffff822ea777 Allocated by task 5297: 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+0x50/0x360 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+0x119/0x260 mm/slub.c:3422 kmem_cache_zalloc include/linux/slab.h:679 [inline] net_alloc net/core/net_namespace.c:410 [inline] copy_net_ns+0x13d/0x5a0 net/core/net_namespace.c:465 create_new_namespaces+0x425/0x7a0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x119/0x170 kernel/nsproxy.c:226 ksys_unshare+0x580/0xb20 kernel/fork.c:3193 __do_sys_unshare kernel/fork.c:3264 [inline] __se_sys_unshare kernel/fork.c:3262 [inline] __x64_sys_unshare+0x34/0x40 kernel/fork.c:3262 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+0x63/0xcd Last potentially related work creation: kasan_save_stack+0x3b/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xb0/0xc0 mm/kasan/generic.c:486 insert_work+0x54/0x3d0 kernel/workqueue.c:1358 __queue_work+0xb59/0xfc0 kernel/workqueue.c:1517 call_timer_fn+0x1e5/0x800 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1514 [inline] __run_timers+0x6a8/0x890 kernel/time/timer.c:1790 __do_softirq+0x304/0xb09 kernel/softirq.c:571 Second to last potentially related work creation: kasan_save_stack+0x3b/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xb0/0xc0 mm/kasan/generic.c:486 insert_work+0x54/0x3d0 kernel/workqueue.c:1358 __queue_work+0xb59/0xfc0 kernel/workqueue.c:1517 queue_work_on+0x14b/0x250 kernel/workqueue.c:1545 xfrm_set_spdinfo+0x3fd/0x5d0 net/xfrm/xfrm_user.c:1385 xfrm_user_rcv_msg+0x6f0/0xa40 net/xfrm/xfrm_user.c:3054 netlink_rcv_skb+0x1cd/0x410 net/netlink/af_netlink.c:2550 xfrm_netlink_rcv+0x70/0x80 net/xfrm/xfrm_user.c:3076 netlink_unicast_kernel net/netlink/af_netlink.c:1328 [inline] netlink_unicast+0x7bf/0x990 net/netlink/af_netlink.c:1354 netlink_sendmsg+0x9fe/0xd10 net/netlink/af_netlink.c:1931 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg net/socket.c:734 [inline] ____sys_sendmsg+0x59e/0x8f0 net/socket.c:2485 ___sys_sendmsg net/socket.c:2539 [inline] __sys_sendmsg+0x2a9/0x390 net/socket.c:2568 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+0x63/0xcd The buggy address belongs to the object at ffff88804927d4c0 which belongs to the cache net_namespace of size 6976 The buggy address is located 1861 bytes inside of 6976-byte region [ffff88804927d4c0, ffff88804927f000) The buggy address belongs to the physical page: page:ffffea0001249e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88804927d4c0 pfn:0x49278 head:ffffea0001249e00 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff88801fdd2601 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffff88801221a348 ffffea00009d6a08 ffff888140007500 raw: ffff88804927d4c0 0000000000040000 00000001ffffffff ffff88801fdd2601 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 4752, tgid 4750 (syz-executor.4), ts 155074780257, free_ts 155048764916 prep_new_page mm/page_alloc.c:2539 [inline] get_page_from_freelist+0x3542/0x36d0 mm/page_alloc.c:4291 __alloc_pages+0x28d/0x7e0 mm/page_alloc.c:5558 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+0xa71/0x1080 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+0x199/0x260 mm/slub.c:3422 kmem_cache_zalloc include/linux/slab.h:679 [inline] net_alloc net/core/net_namespace.c:410 [inline] copy_net_ns+0x13d/0x5a0 net/core/net_namespace.c:465 create_new_namespaces+0x425/0x7a0 kernel/nsproxy.c:110 copy_namespaces+0x325/0x380 kernel/nsproxy.c:178 copy_process+0x1a66/0x3fd0 kernel/fork.c:2259 kernel_clone+0x222/0x9e0 kernel/fork.c:2676 __do_sys_clone kernel/fork.c:2817 [inline] __se_sys_clone kernel/fork.c:2801 [inline] __x64_sys_clone+0x231/0x280 kernel/fork.c:2801 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+0x63/0xcd page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1459 [inline] free_pcp_prepare mm/page_alloc.c:1509 [inline] free_unref_page_prepare+0xfdc/0x1190 mm/page_alloc.c:3387 free_unref_page+0x98/0x570 mm/page_alloc.c:3483 free_slab mm/slub.c:2031 [inline] discard_slab mm/slub.c:2037 [inline] __unfreeze_partials+0x1b7/0x210 mm/slub.c:2586 put_cpu_partial+0x116/0x180 mm/slub.c:2662 qlist_free_all+0x22/0x60 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x162/0x180 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x1f/0x70 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x50/0x360 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+0x119/0x260 mm/slub.c:3422 getname_flags+0xb8/0x4e0 fs/namei.c:139 vfs_fstatat fs/stat.c:266 [inline] __do_sys_newfstatat fs/stat.c:437 [inline] __se_sys_newfstatat+0xe2/0x7b0 fs/stat.c:431 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+0x63/0xcd Memory state around the buggy address: ffff88804927db00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88804927db80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88804927dc00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88804927dc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88804927dd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 45 31 c9 xor %r9d,%r9d 3: 68 e7 67 60 81 pushq $0xffffffff816067e7 8: e8 1c b5 09 00 callq 0x9b529 d: 48 83 c4 08 add $0x8,%rsp 11: 4c 89 ff mov %r15,%rdi 14: e8 e0 cb fe ff callq 0xfffecbf9 19: 66 90 xchg %ax,%ax 1b: 4c 89 ff mov %r15,%rdi 1e: e8 76 7d 2a 09 callq 0x92a7d99 23: e8 a1 74 30 00 callq 0x3074c9 28: fb sti 29: 5b pop %rbx * 2a: 41 5c pop %r12 <-- trapping instruction 2c: 41 5d pop %r13 2e: 41 5e pop %r14 30: 41 5f pop %r15 32: c3 retq 33: 44 89 f1 mov %r14d,%ecx 36: 80 e1 07 and $0x7,%cl 39: 80 c1 03 add $0x3,%cl 3c: 38 c1 cmp %al,%cl 3e: 7c 87 jl 0xffffffc7