================================================================== BUG: KASAN: use-after-free in tcp_retransmit_timer+0x2f87/0x3400 net/ipv4/tcp_timer.c:509 Read of size 8 at addr ffff888078951f00 by task syz-executor.3/3631 CPU: 0 PID: 3631 Comm: syz-executor.3 Not tainted 6.0.0-syzkaller-02770-g79d878f7ad8e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:317 [inline] print_report.cold+0x2ba/0x719 mm/kasan/report.c:433 kasan_report+0xb1/0x1e0 mm/kasan/report.c:495 tcp_retransmit_timer+0x2f87/0x3400 net/ipv4/tcp_timer.c:509 tcp_write_timer_handler net/ipv4/tcp_timer.c:620 [inline] tcp_write_timer_handler+0x4de/0x9f0 net/ipv4/tcp_timer.c:594 tcp_write_timer+0xa2/0x2b0 net/ipv4/tcp_timer.c:637 call_timer_fn+0x1a0/0x6b0 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1519 [inline] __run_timers.part.0+0x674/0xa80 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+0x1d0/0x9c8 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:1107 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:__sanitizer_cov_trace_cmp4+0x4/0x20 kernel/kcov.c:271 Code: 00 00 00 00 66 90 48 8b 0c 24 0f b7 d6 0f b7 f7 bf 02 00 00 00 e9 3c ff ff ff 66 66 2e 0f 1f 84 00 00 00 00 00 90 48 8b 0c 24 <89> f2 89 fe bf 04 00 00 00 e9 1e ff ff ff 66 66 2e 0f 1f 84 00 00 RSP: 0018:ffffc90003e4f848 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff888013a97600 RCX: ffffffff81d05474 RDX: ffff88807b328000 RSI: 0000000000000000 RDI: 0000000000000008 RBP: 0000000000000008 R08: 0000000000000003 R09: 000000000000001f R10: 0000000000000003 R11: 000000000008c07c R12: 00000000001d20c0 R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000003 __set_page_owner_handle+0x104/0x3b0 mm/page_owner.c:165 __set_page_owner+0x3e/0x50 mm/page_owner.c:193 prep_new_page mm/page_alloc.c:2532 [inline] get_page_from_freelist+0x109b/0x2ce0 mm/page_alloc.c:4283 __alloc_pages+0x1c7/0x510 mm/page_alloc.c:5549 alloc_pages+0x1a6/0x270 mm/mempolicy.c:2270 alloc_slab_page mm/slub.c:1829 [inline] allocate_slab+0x27e/0x3d0 mm/slub.c:1974 new_slab mm/slub.c:2034 [inline] ___slab_alloc+0x84f/0xe80 mm/slub.c:3036 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3123 slab_alloc_node mm/slub.c:3214 [inline] slab_alloc mm/slub.c:3256 [inline] __kmem_cache_alloc_lru mm/slub.c:3263 [inline] kmem_cache_alloc+0x38c/0x3b0 mm/slub.c:3273 getname_flags.part.0+0x50/0x4f0 fs/namei.c:139 getname_flags include/linux/audit.h:320 [inline] getname+0x8e/0xd0 fs/namei.c:218 do_sys_openat2+0xf5/0x4c0 fs/open.c:1307 do_sys_open fs/open.c:1329 [inline] __do_sys_openat fs/open.c:1345 [inline] __se_sys_openat fs/open.c:1340 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1340 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: 0033:0x7feee2a3d6a4 Code: 84 00 00 00 00 00 44 89 54 24 0c e8 96 f9 ff ff 44 8b 54 24 0c 44 89 e2 48 89 ee 41 89 c0 bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 77 34 44 89 c7 89 44 24 0c e8 c8 f9 ff ff 8b 44 RSP: 002b:00007ffc5a932fc0 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007ffc5a9330c0 RCX: 00007feee2a3d6a4 RDX: 0000000000000002 RSI: 00007ffc5a933100 RDI: 00000000ffffff9c RBP: 00007ffc5a933100 R08: 0000000000000000 R09: 00007ffc5a932ed0 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000002 R13: 0000000000081dbe R14: 0000000000000002 R15: 00007ffc5a933100 Allocated by task 7100: 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:437 [inline] __kasan_slab_alloc+0x90/0xc0 mm/kasan/common.c:470 kasan_slab_alloc include/linux/kasan.h:224 [inline] slab_post_alloc_hook mm/slab.h:727 [inline] slab_alloc_node mm/slub.c:3248 [inline] slab_alloc mm/slub.c:3256 [inline] __kmem_cache_alloc_lru mm/slub.c:3263 [inline] kmem_cache_alloc+0x267/0x3b0 mm/slub.c:3273 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:3181 __do_sys_unshare kernel/fork.c:3252 [inline] __se_sys_unshare kernel/fork.c:3250 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3250 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 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+0x625/0x1200 kernel/workqueue.c:1517 call_timer_fn+0x1a0/0x6b0 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+0x1d0/0x9c8 kernel/softirq.c:571 The buggy address belongs to the object at ffff888078951c40 which belongs to the cache net_namespace of size 6976 The buggy address is located 704 bytes inside of 6976-byte region [ffff888078951c40, ffff888078953780) The buggy address belongs to the physical page: page:ffffea0001e25400 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888078950000 pfn:0x78950 head:ffffea0001e25400 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff8880736acf81 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0000899a00 dead000000000003 ffff8880119d43c0 raw: ffff888078950000 0000000080040002 00000001ffffffff ffff8880736acf81 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 4868, tgid 4865 (syz-executor.1), ts 173141575116, free_ts 173118853136 prep_new_page mm/page_alloc.c:2532 [inline] get_page_from_freelist+0x109b/0x2ce0 mm/page_alloc.c:4283 __alloc_pages+0x1c7/0x510 mm/page_alloc.c:5549 alloc_pages+0x1a6/0x270 mm/mempolicy.c:2270 alloc_slab_page mm/slub.c:1829 [inline] allocate_slab+0x27e/0x3d0 mm/slub.c:1974 new_slab mm/slub.c:2034 [inline] ___slab_alloc+0x84f/0xe80 mm/slub.c:3036 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3123 slab_alloc_node mm/slub.c:3214 [inline] slab_alloc mm/slub.c:3256 [inline] __kmem_cache_alloc_lru mm/slub.c:3263 [inline] kmem_cache_alloc+0x38c/0x3b0 mm/slub.c:3273 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 copy_namespaces+0x391/0x450 kernel/nsproxy.c:178 copy_process+0x304d/0x7090 kernel/fork.c:2257 kernel_clone+0xe7/0xab0 kernel/fork.c:2671 __do_sys_clone+0xba/0x100 kernel/fork.c:2805 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:1449 [inline] free_pcp_prepare+0x5e4/0xd20 mm/page_alloc.c:1499 free_unref_page_prepare mm/page_alloc.c:3380 [inline] free_unref_page+0x19/0x4d0 mm/page_alloc.c:3476 __unfreeze_partials+0x17c/0x1a0 mm/slub.c:2553 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:447 kasan_slab_alloc include/linux/kasan.h:224 [inline] slab_post_alloc_hook mm/slab.h:727 [inline] slab_alloc_node mm/slub.c:3248 [inline] slab_alloc mm/slub.c:3256 [inline] __kmem_cache_alloc_lru mm/slub.c:3263 [inline] kmem_cache_alloc+0x267/0x3b0 mm/slub.c:3273 getname_flags.part.0+0x50/0x4f0 fs/namei.c:139 getname_flags+0x9a/0xe0 include/linux/audit.h:320 vfs_fstatat+0x73/0xb0 fs/stat.c:266 __do_sys_newfstatat+0x94/0x120 fs/stat.c:437 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 Memory state around the buggy address: ffff888078951e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888078951e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888078951f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888078951f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888078952000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: 00 00 add %al,(%rax) 4: 66 90 xchg %ax,%ax 6: 48 8b 0c 24 mov (%rsp),%rcx a: 0f b7 d6 movzwl %si,%edx d: 0f b7 f7 movzwl %di,%esi 10: bf 02 00 00 00 mov $0x2,%edi 15: e9 3c ff ff ff jmpq 0xffffff56 1a: 66 66 2e 0f 1f 84 00 data16 nopw %cs:0x0(%rax,%rax,1) 21: 00 00 00 00 25: 90 nop 26: 48 8b 0c 24 mov (%rsp),%rcx * 2a: 89 f2 mov %esi,%edx <-- trapping instruction 2c: 89 fe mov %edi,%esi 2e: bf 04 00 00 00 mov $0x4,%edi 33: e9 1e ff ff ff jmpq 0xffffff56 38: 66 data16 39: 66 data16 3a: 2e cs 3b: 0f .byte 0xf 3c: 1f (bad) 3d: 84 00 test %al,(%rax)