================================================================== 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 ffff88807de78745 by task syz-executor.0/19815 CPU: 0 PID: 19815 Comm: syz-executor.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:lock_release+0x637/0xa20 kernel/locking/lockdep.c:5686 Code: 3c 3b 00 74 08 4c 89 f7 e8 06 7b 77 00 f6 84 24 91 00 00 00 02 75 6f 41 f7 c5 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 27 00 00 00 00 4b c7 44 27 08 00 00 00 00 65 48 8b 04 25 RSP: 0018:ffffc9000357f160 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff920006afe3e RCX: ffffc9000357f103 RDX: 0000000000000002 RSI: ffffffff8aebffc0 RDI: ffffffff8b3d2b40 RBP: ffffc9000357f290 R08: dffffc0000000000 R09: fffffbfff1ce6c56 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff920006afe38 R13: 0000000000000246 R14: ffffc9000357f1f0 R15: dffffc0000000000 rcu_lock_release include/linux/rcupdate.h:324 [inline] rcu_read_unlock_sched include/linux/rcupdate.h:873 [inline] pfn_valid+0x3e0/0x440 include/linux/mmzone.h:1867 page_table_check_clear+0x21/0x720 mm/page_table_check.c:67 zap_pte_range mm/memory.c:1435 [inline] zap_pmd_range mm/memory.c:1574 [inline] zap_pud_range mm/memory.c:1603 [inline] zap_p4d_range mm/memory.c:1624 [inline] unmap_page_range+0x1b4a/0x2740 mm/memory.c:1645 unmap_vmas+0x48b/0x640 mm/memory.c:1730 exit_mmap+0x252/0x9f0 mm/mmap.c:3227 __mmput+0x115/0x3c0 kernel/fork.c:1199 exit_mm+0x226/0x300 kernel/exit.c:563 do_exit+0x9f6/0x26a0 kernel/exit.c:856 do_group_exit+0x202/0x2b0 kernel/exit.c:1019 get_signal+0x16f7/0x17d0 kernel/signal.c:2862 arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:168 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:297 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f98be47dda9 Code: Unable to access opcode bytes at 0x7f98be47dd7f. RSP: 002b:00007f98bf16a178 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f98be5abf88 RCX: 00007f98be47dda9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f98be5abf88 RBP: 00007f98be5abf80 R08: 00007f98bf16a6c0 R09: 00007f98bf16a6c0 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f98be5abf8c R13: 000000000000000b R14: 00007fffd0c023d0 R15: 00007fffd0c024b8 Allocated by task 3576: 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 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:1361 __queue_work+0xb4b/0xf90 kernel/workqueue.c:1520 call_timer_fn+0x1ad/0x6b0 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1514 [inline] __run_timers+0x6a8/0x890 kernel/time/timer.c:1790 __do_softirq+0x2e9/0xa4c 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:1361 __queue_work+0xb4b/0xf90 kernel/workqueue.c:1520 call_timer_fn+0x1ad/0x6b0 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1514 [inline] __run_timers+0x6a8/0x890 kernel/time/timer.c:1790 __do_softirq+0x2e9/0xa4c kernel/softirq.c:571 The buggy address belongs to the object at ffff88807de78000 which belongs to the cache net_namespace of size 6976 The buggy address is located 1861 bytes inside of 6976-byte region [ffff88807de78000, ffff88807de79b40) The buggy address belongs to the physical page: page:ffffea0001f79e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88807de78000 pfn:0x7de78 head:ffffea0001f79e00 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff88809bb00001 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000001 ffff888140009500 raw: ffff88807de78000 0000000080040000 00000001ffffffff ffff88809bb00001 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 3576, tgid 3576 (syz-executor.0), ts 122615530914, free_ts 122611116199 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 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+0x17b/0x250 mm/slub.c:2662 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x76/0xe0 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x156/0x170 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+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 getname_flags+0xb8/0x4f0 fs/namei.c:139 do_sys_openat2+0xd2/0x500 fs/open.c:1312 do_sys_open fs/open.c:1334 [inline] __do_sys_openat fs/open.c:1350 [inline] __se_sys_openat fs/open.c:1345 [inline] __x64_sys_openat+0x243/0x290 fs/open.c:1345 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: ffff88807de78600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807de78680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807de78700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807de78780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807de78800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 3c 3b cmp $0x3b,%al 2: 00 74 08 4c add %dh,0x4c(%rax,%rcx,1) 6: 89 f7 mov %esi,%edi 8: e8 06 7b 77 00 call 0x777b13 d: f6 84 24 91 00 00 00 testb $0x2,0x91(%rsp) 14: 02 15: 75 6f jne 0x86 17: 41 f7 c5 00 02 00 00 test $0x200,%r13d 1e: 74 01 je 0x21 20: fb sti 21: 48 c7 44 24 60 0e 36 movq $0x45e0360e,0x60(%rsp) 28: e0 45 * 2a: 4b c7 04 27 00 00 00 movq $0x0,(%r15,%r12,1) <-- trapping instruction 31: 00 32: 4b c7 44 27 08 00 00 movq $0x0,0x8(%r15,%r12,1) 39: 00 00 3b: 65 gs 3c: 48 rex.W 3d: 8b .byte 0x8b 3e: 04 25 add $0x25,%al