================================================================== BUG: KASAN: use-after-free in tcp_retransmit_timer+0x2ef3/0x3360 net/ipv4/tcp_timer.c:511 Read of size 8 at addr ffff888077ded540 by task dhcpcd-run-hook/15552 CPU: 1 PID: 15552 Comm: dhcpcd-run-hook Not tainted 5.18.0-syzkaller-04999-g0a375c822497 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/13/2022 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_retransmit_timer+0x2ef3/0x3360 net/ipv4/tcp_timer.c:511 tcp_write_timer_handler+0x5e6/0xbc0 net/ipv4/tcp_timer.c:622 tcp_write_timer+0xa2/0x2b0 net/ipv4/tcp_timer.c:642 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:on_stack arch/x86/include/asm/stacktrace.h:56 [inline] RIP: 0010:unwind_next_frame+0x1491/0x1cc0 arch/x86/kernel/unwind_orc.c:617 Code: 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 f2 06 00 00 49 8d 7d 10 49 8b 6d 08 48 b8 00 00 00 00 00 fc ff df 48 89 fa <48> c1 ea 03 80 3c 02 00 0f 85 c5 06 00 00 48 39 dd 49 8b 45 10 0f RSP: 0018:ffffc90002bff8e0 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: 00007ffd8cf6bf58 RCX: 1ffff9200057ff31 RDX: ffffc90002bff960 RSI: ffffc90002bfff58 RDI: ffffc90002bff960 RBP: ffffc90002bf8000 R08: ffffffff8ed2bd28 R09: ffffc90002bff984 R10: fffff5200057ff35 R11: 000000000008a079 R12: ffffc90002bfff58 R13: ffffc90002bff950 R14: ffffc90002bfff58 R15: ffffffff8ed2bd2c arch_stack_walk+0x7d/0xe0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:122 save_stack+0x151/0x1e0 mm/page_owner.c:127 __reset_page_owner+0x5d/0x180 mm/page_owner.c:148 reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1356 [inline] free_pcp_prepare+0x549/0xd20 mm/page_alloc.c:1406 free_unref_page_prepare mm/page_alloc.c:3328 [inline] free_unref_page+0x19/0x6a0 mm/page_alloc.c:3423 __unfreeze_partials+0x17c/0x1a0 mm/slub.c:2521 qlink_free mm/kasan/quarantine.c:157 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:283 __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:3214 [inline] slab_alloc mm/slub.c:3222 [inline] __kmem_cache_alloc_lru mm/slub.c:3229 [inline] kmem_cache_alloc_lru+0x255/0x720 mm/slub.c:3246 alloc_inode_sb include/linux/fs.h:2957 [inline] alloc_inode+0x168/0x230 fs/inode.c:262 new_inode_pseudo+0x14/0xe0 fs/inode.c:1018 get_pipe_inode fs/pipe.c:873 [inline] create_pipe_files+0x4d/0x880 fs/pipe.c:913 __do_pipe_flags fs/pipe.c:962 [inline] do_pipe2+0x96/0x1b0 fs/pipe.c:1010 __do_sys_pipe fs/pipe.c:1033 [inline] __se_sys_pipe fs/pipe.c:1031 [inline] __x64_sys_pipe+0x2f/0x40 fs/pipe.c:1031 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 RIP: 0033:0x7f28a77230d7 Code: 73 01 c3 48 8b 0d a1 ed 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 16 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 71 ed 0c 00 f7 d8 64 89 01 48 RSP: 002b:00007ffd8cf6bf58 EFLAGS: 00000202 ORIG_RAX: 0000000000000016 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f28a77230d7 RDX: 00007f28a7894700 RSI: 0000000000000000 RDI: 00007ffd8cf6bfb0 RBP: 000055fbd549eee1 R08: 000055fbd5497798 R09: 000055fbd549cd60 R10: 0000000000000000 R11: 0000000000000202 R12: 000055fbd549e838 R13: 00007f28a78be460 R14: 0000000000000001 R15: 0000000000000000 Allocated by task 3613: 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:3214 [inline] slab_alloc mm/slub.c:3222 [inline] __kmem_cache_alloc_lru mm/slub.c:3229 [inline] kmem_cache_alloc+0x204/0x3b0 mm/slub.c:3239 kmem_cache_zalloc include/linux/slab.h:711 [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:3137 __do_sys_unshare kernel/fork.c:3208 [inline] __se_sys_unshare kernel/fork.c:3206 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3206 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 4732: 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:1727 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1753 slab_free mm/slub.c:3507 [inline] kmem_cache_free+0xdd/0x5a0 mm/slub.c:3524 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+0x62e/0x1140 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+0x62e/0x1140 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 ffff888077ded280 which belongs to the cache net_namespace of size 6784 The buggy address is located 704 bytes inside of 6784-byte region [ffff888077ded280, ffff888077deed00) The buggy address belongs to the physical page: page:ffffea0001df7a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x77de8 head:ffffea0001df7a00 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000122 ffff8881400073c0 raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000 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 3611, tgid 3611 (syz-executor.0), ts 46685498060, free_ts 46657045480 prep_new_page mm/page_alloc.c:2441 [inline] get_page_from_freelist+0xba2/0x3e00 mm/page_alloc.c:4182 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5408 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2272 alloc_slab_page mm/slub.c:1797 [inline] allocate_slab+0x26c/0x3c0 mm/slub.c:1942 new_slab mm/slub.c:2002 [inline] ___slab_alloc+0x985/0xd90 mm/slub.c:3002 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3089 slab_alloc_node mm/slub.c:3180 [inline] slab_alloc mm/slub.c:3222 [inline] __kmem_cache_alloc_lru mm/slub.c:3229 [inline] kmem_cache_alloc+0x360/0x3b0 mm/slub.c:3239 kmem_cache_zalloc include/linux/slab.h:711 [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:3137 __do_sys_unshare kernel/fork.c:3208 [inline] __se_sys_unshare kernel/fork.c:3206 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3206 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:1356 [inline] free_pcp_prepare+0x549/0xd20 mm/page_alloc.c:1406 free_unref_page_prepare mm/page_alloc.c:3328 [inline] free_unref_page+0x19/0x6a0 mm/page_alloc.c:3423 __unfreeze_partials+0x17c/0x1a0 mm/slub.c:2521 qlink_free mm/kasan/quarantine.c:157 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:283 __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:3214 [inline] slab_alloc mm/slub.c:3222 [inline] __kmem_cache_alloc_lru mm/slub.c:3229 [inline] kmem_cache_alloc+0x204/0x3b0 mm/slub.c:3239 create_nsproxy kernel/nsproxy.c:56 [inline] create_new_namespaces+0x30/0xb20 kernel/nsproxy.c:74 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:226 ksys_unshare+0x445/0x920 kernel/fork.c:3137 __do_sys_unshare kernel/fork.c:3208 [inline] __se_sys_unshare kernel/fork.c:3206 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3206 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: ffff888077ded400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888077ded480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888077ded500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888077ded580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888077ded600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess), 3 bytes skipped: 0: df 48 89 fisttps -0x77(%rax) 3: fa cli 4: 48 c1 ea 03 shr $0x3,%rdx 8: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) c: 0f 85 f2 06 00 00 jne 0x704 12: 49 8d 7d 10 lea 0x10(%r13),%rdi 16: 49 8b 6d 08 mov 0x8(%r13),%rbp 1a: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 21: fc ff df 24: 48 89 fa mov %rdi,%rdx * 27: 48 c1 ea 03 shr $0x3,%rdx <-- trapping instruction 2b: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) 2f: 0f 85 c5 06 00 00 jne 0x6fa 35: 48 39 dd cmp %rbx,%rbp 38: 49 8b 45 10 mov 0x10(%r13),%rax 3c: 0f .byte 0xf