================================================================== BUG: KASAN: use-after-free in tcp_retransmit_timer+0x2ef3/0x3360 net/ipv4/tcp_timer.c:505 Read of size 8 at addr ffff888049e79e40 by task syz-executor.4/19788 CPU: 1 PID: 19788 Comm: syz-executor.4 Not tainted 5.19.0-rc3-syzkaller-00644-gd521bc0a0f7c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 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_retransmit_timer+0x2ef3/0x3360 net/ipv4/tcp_timer.c:505 tcp_write_timer_handler net/ipv4/tcp_timer.c:616 [inline] tcp_write_timer_handler+0x4de/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:arch_atomic_read arch/x86/include/asm/atomic.h:29 [inline] RIP: 0010:atomic_read include/linux/atomic/atomic-instrumented.h:28 [inline] RIP: 0010:folio_memcg_lock+0x19b/0x6c0 mm/memcontrol.c:2057 Code: e2 03 00 00 4d 85 ed 74 01 fb 4c 8d ab 80 11 00 00 be 04 00 00 00 4c 89 ef e8 41 d2 f8 ff 4c 89 e8 48 c1 e8 03 42 0f b6 14 20 <4c> 89 e8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 3c 04 00 00 8b RSP: 0018:ffffc90002def6b8 EFLAGS: 00000a06 RAX: 1ffff11027fcc230 RBX: ffff88813fe60000 RCX: ffffffff81cea0ff RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff88813fe61180 RBP: ffffc90002def708 R08: 0000000000000000 R09: ffff88813fe61183 R10: ffffed1027fcc230 R11: 0000000000000001 R12: dffffc0000000000 R13: ffff88813fe61180 R14: ffffea0001d1aa38 R15: ffffea0001d1aa08 page_remove_rmap+0x27/0x1510 mm/rmap.c:1429 zap_pte_range mm/memory.c:1446 [inline] zap_pmd_range mm/memory.c:1567 [inline] zap_pud_range mm/memory.c:1596 [inline] zap_p4d_range mm/memory.c:1617 [inline] unmap_page_range+0x1014/0x3710 mm/memory.c:1638 unmap_single_vma+0x196/0x360 mm/memory.c:1686 unmap_vmas+0x18c/0x310 mm/memory.c:1723 exit_mmap+0x1c4/0x4a0 mm/mmap.c:3162 __mmput+0x122/0x4b0 kernel/fork.c:1187 mmput+0x56/0x60 kernel/fork.c:1208 exit_mm kernel/exit.c:510 [inline] do_exit+0xa12/0x2a00 kernel/exit.c:782 do_group_exit+0xd2/0x2f0 kernel/exit.c:925 get_signal+0x2542/0x2600 kernel/signal.c:2857 arch_do_signal_or_restart+0x82/0x2300 arch/x86/kernel/signal.c:869 exit_to_user_mode_loop kernel/entry/common.c:166 [inline] exit_to_user_mode_prepare+0x15f/0x250 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:294 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x7f96c1489109 Code: Unable to access opcode bytes at RIP 0x7f96c14890df. RSP: 002b:00007f96c25cf218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000001 RBX: 00007f96c159bf68 RCX: 00007f96c1489109 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f96c159bf6c RBP: 00007f96c159bf60 R08: 00007ffcbb557080 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 00007f96c159bf6c R13: 00007ffcbb53efbf R14: 00007f96c25cf300 R15: 0000000000022000 Allocated by task 6872: 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 Freed by task 8: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track+0x21/0x30 mm/kasan/common.c:45 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free+0x166/0x1a0 mm/kasan/common.c:328 kasan_slab_free include/linux/kasan.h:200 [inline] slab_free_hook mm/slub.c:1754 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1780 slab_free mm/slub.c:3536 [inline] kmem_cache_free+0xdd/0x5a0 mm/slub.c:3553 net_free net/core/net_namespace.c:432 [inline] net_free net/core/net_namespace.c:428 [inline] cleanup_net+0x8ba/0xb00 net/core/net_namespace.c:615 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 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 ffff888049e79b80 which belongs to the cache net_namespace of size 6784 The buggy address is located 704 bytes inside of 6784-byte region [ffff888049e79b80, ffff888049e7b600) The buggy address belongs to the physical page: page:ffffea0001279e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888049e78000 pfn:0x49e78 head:ffffea0001279e00 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff888017648581 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0001e59c08 ffff8880119cf288 ffff8881400073c0 raw: ffff888049e78000 0000000000040001 00000001ffffffff ffff888017648581 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 6827, tgid 6826 (syz-executor.4), ts 230898642309, free_ts 230892640993 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] 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 anon_vma_chain_alloc mm/rmap.c:140 [inline] anon_vma_fork+0x1df/0x630 mm/rmap.c:361 dup_mmap kernel/fork.c:658 [inline] dup_mm+0xa07/0x1390 kernel/fork.c:1524 copy_mm kernel/fork.c:1576 [inline] copy_process+0x3bba/0x7020 kernel/fork.c:2240 kernel_clone+0xe7/0xab0 kernel/fork.c:2655 __do_sys_clone+0xba/0x100 kernel/fork.c:2789 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 Memory state around the buggy address: ffff888049e79d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888049e79d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888049e79e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888049e79e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888049e79f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: e2 03 loop 0x5 2: 00 00 add %al,(%rax) 4: 4d 85 ed test %r13,%r13 7: 74 01 je 0xa 9: fb sti a: 4c 8d ab 80 11 00 00 lea 0x1180(%rbx),%r13 11: be 04 00 00 00 mov $0x4,%esi 16: 4c 89 ef mov %r13,%rdi 19: e8 41 d2 f8 ff callq 0xfff8d25f 1e: 4c 89 e8 mov %r13,%rax 21: 48 c1 e8 03 shr $0x3,%rax 25: 42 0f b6 14 20 movzbl (%rax,%r12,1),%edx * 2a: 4c 89 e8 mov %r13,%rax <-- trapping instruction 2d: 83 e0 07 and $0x7,%eax 30: 83 c0 03 add $0x3,%eax 33: 38 d0 cmp %dl,%al 35: 7c 08 jl 0x3f 37: 84 d2 test %dl,%dl 39: 0f 85 3c 04 00 00 jne 0x47b 3f: 8b .byte 0x8b