================================================================== BUG: KASAN: use-after-free in tcp_probe_timer net/ipv4/tcp_timer.c:384 [inline] BUG: KASAN: use-after-free in tcp_write_timer_handler+0xb91/0xbc0 net/ipv4/tcp_timer.c:630 Read of size 1 at addr ffff888057f20695 by task dhcpcd-run-hook/19221 CPU: 1 PID: 19221 Comm: dhcpcd-run-hook Not tainted 5.19.0-rc8-syzkaller-00130-g8eaa1d110800 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 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_probe_timer net/ipv4/tcp_timer.c:384 [inline] tcp_write_timer_handler+0xb91/0xbc0 net/ipv4/tcp_timer.c:630 tcp_write_timer+0xa2/0x2b0 net/ipv4/tcp_timer.c:646 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+0x16/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:__sanitizer_cov_trace_pc+0x37/0x60 kernel/kcov.c:200 Code: 81 e1 00 01 00 00 65 48 8b 14 25 80 6f 02 00 a9 00 01 ff 00 74 0e 85 c9 74 35 8b 82 a4 15 00 00 85 c0 74 2b 8b 82 80 15 00 00 <83> f8 02 75 20 48 8b 8a 88 15 00 00 8b 92 84 15 00 00 48 8b 01 48 RSP: 0018:ffffc9000430f808 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff88801fbe8000 RSI: ffffffff81b40983 RDI: 0000000000000005 RBP: ffffc9000430f9f8 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000004 R13: dffffc0000000000 R14: ffff888076535f10 R15: 0000000000000000 add_mm_rss_vec mm/memory.c:507 [inline] copy_pte_range mm/memory.c:1101 [inline] copy_pmd_range mm/memory.c:1163 [inline] copy_pud_range mm/memory.c:1200 [inline] copy_p4d_range mm/memory.c:1224 [inline] copy_page_range+0x1163/0x38a0 mm/memory.c:1322 dup_mmap kernel/fork.c:699 [inline] dup_mm+0xa4e/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+0x63/0xcd RIP: 0033:0x7fd8803e60f2 Code: ed 0f 85 11 01 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 a2 00 00 00 41 89 c5 85 c0 0f 85 af 00 00 RSP: 002b:00007ffedd498290 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000564151db30b0 RCX: 00007fd8803e60f2 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 00007fd88027cad0 R11: 0000000000000246 R12: 0000000000000000 R13: 0000564151dc2d50 R14: 0000000000000002 R15: 0000000000000005 Allocated by task 3625: 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+0x63/0xcd Freed by task 11: 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:306 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 Second to 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 ffff888057f20000 which belongs to the cache net_namespace of size 6784 The buggy address is located 1685 bytes inside of 6784-byte region [ffff888057f20000, ffff888057f21a80) The buggy address belongs to the physical page: page:ffffea00015fc800 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888057f21b80 pfn:0x57f20 head:ffffea00015fc800 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff888016c59ec1 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea00010e6800 dead000000000002 ffff8881400073c0 raw: ffff888057f21b80 0000000080040002 00000001ffffffff ffff888016c59ec1 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 3625, tgid 3625 (syz-executor.4), ts 61769957784, free_ts 11893750940 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+0x63/0xcd 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 free_contig_range+0xb1/0x180 mm/page_alloc.c:9314 destroy_args+0xa8/0x646 mm/debug_vm_pgtable.c:1031 debug_vm_pgtable+0x2a03/0x2a94 mm/debug_vm_pgtable.c:1354 do_one_initcall+0x103/0x650 init/main.c:1295 do_initcall_level init/main.c:1368 [inline] do_initcalls init/main.c:1384 [inline] do_basic_setup init/main.c:1403 [inline] kernel_init_freeable+0x6b1/0x73a init/main.c:1610 kernel_init+0x1a/0x1d0 init/main.c:1499 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 Memory state around the buggy address: ffff888057f20580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888057f20600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888057f20680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888057f20700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888057f20780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 81 e1 00 01 00 00 and $0x100,%ecx 6: 65 48 8b 14 25 80 6f mov %gs:0x26f80,%rdx d: 02 00 f: a9 00 01 ff 00 test $0xff0100,%eax 14: 74 0e je 0x24 16: 85 c9 test %ecx,%ecx 18: 74 35 je 0x4f 1a: 8b 82 a4 15 00 00 mov 0x15a4(%rdx),%eax 20: 85 c0 test %eax,%eax 22: 74 2b je 0x4f 24: 8b 82 80 15 00 00 mov 0x1580(%rdx),%eax * 2a: 83 f8 02 cmp $0x2,%eax <-- trapping instruction 2d: 75 20 jne 0x4f 2f: 48 8b 8a 88 15 00 00 mov 0x1588(%rdx),%rcx 36: 8b 92 84 15 00 00 mov 0x1584(%rdx),%edx 3c: 48 8b 01 mov (%rcx),%rax 3f: 48 rex.W