================================================================== BUG: KASAN: use-after-free in tcp_retransmit_timer+0x6ee/0x2890 net/ipv4/tcp_timer.c:515 Read of size 8 at addr ffff88801f2036d8 by task syz-executor.1/3601 CPU: 1 PID: 3601 Comm: syz-executor.1 Not tainted 5.15.107-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 print_address_description+0x63/0x3b0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0x16b/0x1c0 mm/kasan/report.c:451 tcp_retransmit_timer+0x6ee/0x2890 net/ipv4/tcp_timer.c:515 tcp_write_timer_handler+0x1f7/0x9c0 net/ipv4/tcp_timer.c:626 tcp_write_timer+0x12e/0x280 net/ipv4/tcp_timer.c:646 call_timer_fn+0x16d/0x560 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1466 [inline] __run_timers+0x67c/0x890 kernel/time/timer.c:1737 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1750 __do_softirq+0x3b3/0x93a kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x155/0x240 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__raw_write_unlock_irq include/linux/rwlock_api_smp.h:268 [inline] RIP: 0010:_raw_write_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:348 Code: 91 a0 f6 ff 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 8e f6 41 f7 48 89 df e8 c6 5a 43 f7 e8 61 c3 65 f7 fb bf 01 00 00 00 b6 89 36 f7 65 8b 05 d7 08 e2 75 85 c0 74 02 5b c3 e8 e4 1f e0 RSP: 0018:ffffc90002e6f870 EFLAGS: 00000282 RAX: b81d326c3ee3a800 RBX: ffffffff8c60a040 RCX: ffffffff913aef03 RDX: dffffc0000000000 RSI: ffffffff8a8af0e0 RDI: 0000000000000001 RBP: ffffc90002e6f9d0 R08: ffffffff81862a70 R09: fffffbfff1bc6396 R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000 R13: ffff8880236bd700 R14: ffff8880207ece10 R15: ffff8880236bd700 release_task+0x1532/0x16e0 kernel/exit.c:267 wait_task_zombie kernel/exit.c:1179 [inline] wait_consider_task+0x1997/0x2e50 kernel/exit.c:1406 do_wait_thread kernel/exit.c:1469 [inline] do_wait+0x30c/0xaf0 kernel/exit.c:1586 kernel_wait4+0x29e/0x3e0 kernel/exit.c:1749 __do_sys_wait4 kernel/exit.c:1777 [inline] __se_sys_wait4 kernel/exit.c:1773 [inline] __x64_sys_wait4+0x130/0x1e0 kernel/exit.c:1773 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f4d458c7d47 Code: 89 7c 24 10 48 89 4c 24 18 e8 f5 58 02 00 4c 8b 54 24 18 8b 54 24 14 41 89 c0 48 8b 74 24 08 8b 7c 24 10 b8 3d 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 89 44 24 10 e8 25 59 02 00 8b 44 RSP: 002b:00007fffb171f3c0 EFLAGS: 00000293 ORIG_RAX: 000000000000003d RAX: ffffffffffffffda RBX: 000000000000175a RCX: 00007f4d458c7d47 RDX: 0000000040000001 RSI: 00007fffb171f44c RDI: 00000000ffffffff RBP: 00007fffb171f44c R08: 0000000000000000 R09: 0000000000000010 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000032 R13: 00000000000fb161 R14: 0000000000000009 R15: 00007fffb171f4b0 Allocated by task 3617: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] __kasan_slab_alloc+0x8e/0xc0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x53/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3220 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc+0xf3/0x280 mm/slub.c:3233 kmem_cache_zalloc include/linux/slab.h:711 [inline] net_alloc net/core/net_namespace.c:405 [inline] copy_net_ns+0x143/0x5d0 net/core/net_namespace.c:460 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:3094 __do_sys_unshare kernel/fork.c:3168 [inline] __se_sys_unshare kernel/fork.c:3166 [inline] __x64_sys_unshare+0x34/0x40 kernel/fork.c:3166 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb Freed by task 144: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x80 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd8/0x120 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1705 [inline] slab_free_freelist_hook+0xdd/0x160 mm/slub.c:1731 slab_free mm/slub.c:3499 [inline] kmem_cache_free+0x91/0x1f0 mm/slub.c:3515 net_free net/core/net_namespace.c:434 [inline] cleanup_net+0xab5/0xb60 net/core/net_namespace.c:617 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2306 worker_thread+0xaca/0x1280 kernel/workqueue.c:2453 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 The buggy address belongs to the object at ffff88801f203480 which belongs to the cache net_namespace of size 6464 The buggy address is located 600 bytes inside of 6464-byte region [ffff88801f203480, ffff88801f204dc0) The buggy address belongs to the page: page:ffffea00007c8000 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88801f204ec0 pfn:0x1f200 head:ffffea00007c8000 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff888013da7101 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0001eb4200 0000000200000002 ffff888011dc63c0 raw: ffff88801f204ec0 0000000080040003 00000001ffffffff ffff888013da7101 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 3608, ts 48337206969, free_ts 48327781370 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x322a/0x33c0 mm/page_alloc.c:4159 __alloc_pages+0x272/0x700 mm/page_alloc.c:5421 alloc_slab_page mm/slub.c:1775 [inline] allocate_slab mm/slub.c:1912 [inline] new_slab+0xbb/0x4b0 mm/slub.c:1975 ___slab_alloc+0x6f6/0xe10 mm/slub.c:3008 __slab_alloc mm/slub.c:3095 [inline] slab_alloc_node mm/slub.c:3186 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc+0x18e/0x280 mm/slub.c:3233 kmem_cache_zalloc include/linux/slab.h:711 [inline] net_alloc net/core/net_namespace.c:405 [inline] copy_net_ns+0x143/0x5d0 net/core/net_namespace.c:460 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:3094 __do_sys_unshare kernel/fork.c:3168 [inline] __se_sys_unshare kernel/fork.c:3166 [inline] __x64_sys_unshare+0x34/0x40 kernel/fork.c:3166 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0xc34/0xcf0 mm/page_alloc.c:3317 free_unref_page+0x95/0x2d0 mm/page_alloc.c:3396 free_slab mm/slub.c:2015 [inline] discard_slab mm/slub.c:2021 [inline] __unfreeze_partials+0x1b7/0x210 mm/slub.c:2507 put_cpu_partial+0x132/0x1a0 mm/slub.c:2587 do_slab_free mm/slub.c:3487 [inline] ___cache_free+0xe3/0x100 mm/slub.c:3506 qlist_free_all+0x36/0x90 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x162/0x180 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xc0 mm/kasan/common.c:444 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x53/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3220 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc_trace+0xfb/0x290 mm/slub.c:3245 kmalloc include/linux/slab.h:591 [inline] kzalloc include/linux/slab.h:721 [inline] kernfs_fop_open+0x3b5/0xbc0 fs/kernfs/file.c:628 do_dentry_open+0x807/0xfb0 fs/open.c:826 do_open fs/namei.c:3538 [inline] path_openat+0x2702/0x2f20 fs/namei.c:3672 do_filp_open+0x21c/0x460 fs/namei.c:3699 do_sys_openat2+0x13b/0x500 fs/open.c:1211 do_sys_open fs/open.c:1227 [inline] __do_sys_openat fs/open.c:1243 [inline] __se_sys_openat fs/open.c:1238 [inline] __x64_sys_openat+0x243/0x290 fs/open.c:1238 Memory state around the buggy address: ffff88801f203580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801f203600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88801f203680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801f203700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801f203780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 91 xchg %eax,%ecx 1: a0 f6 ff 90 53 48 89 movabs 0x48fb89485390fff6,%al 8: fb 48 a: 83 c7 18 add $0x18,%edi d: 48 8b 74 24 08 mov 0x8(%rsp),%rsi 12: e8 8e f6 41 f7 callq 0xf741f6a5 17: 48 89 df mov %rbx,%rdi 1a: e8 c6 5a 43 f7 callq 0xf7435ae5 1f: e8 61 c3 65 f7 callq 0xf765c385 24: fb sti 25: bf 01 00 00 00 mov $0x1,%edi * 2a: e8 b6 89 36 f7 callq 0xf73689e5 <-- trapping instruction 2f: 65 8b 05 d7 08 e2 75 mov %gs:0x75e208d7(%rip),%eax # 0x75e2090d 36: 85 c0 test %eax,%eax 38: 74 02 je 0x3c 3a: 5b pop %rbx 3b: c3 retq 3c: e8 .byte 0xe8 3d: e4 1f in $0x1f,%al 3f: e0 .byte 0xe0