================================================================== BUG: KASAN: use-after-free in tcp_retransmit_timer+0x6ee/0x2890 net/ipv4/tcp_timer.c:515 Read of size 8 at addr ffff88807c3d5118 by task syz-executor.1/14988 CPU: 0 PID: 14988 Comm: syz-executor.1 Not tainted 5.15.112-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023 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:1096 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:copy_pte_range mm/memory.c:1070 [inline] RIP: 0010:copy_pmd_range mm/memory.c:1156 [inline] RIP: 0010:copy_pud_range mm/memory.c:1193 [inline] RIP: 0010:copy_p4d_range mm/memory.c:1217 [inline] RIP: 0010:copy_page_range+0x1a4d/0x43b0 mm/memory.c:1290 Code: 4c 8d b4 24 00 02 00 00 49 c1 ee 03 48 b8 00 00 00 00 00 fc ff df 41 80 3c 06 00 74 0d 48 8d bc 24 00 02 00 00 e8 83 fe 11 00 <48> 89 9c 24 00 02 00 00 48 b8 00 00 00 00 00 fc ff df 41 80 3c 06 RSP: 0018:ffffc9000318f5c0 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: 80000000532f7007 RCX: ffff88807e025940 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000318f930 R08: ffffffff81b74626 R09: fffff940002997b9 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff8880194c9b58 R13: 00fff00000000000 R14: 1ffff92000631ef8 R15: ffff8880194c9ba8 dup_mmap kernel/fork.c:613 [inline] dup_mm+0xad6/0x1230 kernel/fork.c:1457 copy_mm+0x101/0x190 kernel/fork.c:1509 copy_process+0x1816/0x3ef0 kernel/fork.c:2198 kernel_clone+0x210/0x960 kernel/fork.c:2601 __do_sys_clone kernel/fork.c:2718 [inline] __se_sys_clone kernel/fork.c:2702 [inline] __x64_sys_clone+0x23f/0x290 kernel/fork.c:2702 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: 0033:0x7fcba7bbce9b Code: ed 0f 85 60 01 00 00 64 4c 8b 0c 25 10 00 00 00 45 31 c0 4d 8d 91 d0 02 00 00 31 d2 31 f6 bf 11 00 20 01 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 89 00 00 00 41 89 c5 85 c0 0f 85 90 00 00 RSP: 002b:00007ffe5fda5bc0 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fcba7bbce9b RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 00005555562ae400 R10: 00005555562ae6d0 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000001 R15: 00007ffe5fda5ca0 Allocated by task 3540: 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 891: 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:2307 worker_thread+0xaca/0x1280 kernel/workqueue.c:2454 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 ffff88807c3d4ec0 which belongs to the cache net_namespace of size 6464 The buggy address is located 600 bytes inside of 6464-byte region [ffff88807c3d4ec0, ffff88807c3d6800) The buggy address belongs to the page: page:ffffea0001f0f400 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88807c3d3480 pfn:0x7c3d0 head:ffffea0001f0f400 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff88801b49cfc1 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffff888011dc7288 ffffea0001f7c408 ffff888011dc63c0 raw: ffff88807c3d3480 0000000000040002 00000001ffffffff ffff88801b49cfc1 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 3524, ts 91817823436, free_ts 91815747702 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: ffff88807c3d5000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807c3d5080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807c3d5100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807c3d5180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807c3d5200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 4c 8d b4 24 00 02 00 lea 0x200(%rsp),%r14 7: 00 8: 49 c1 ee 03 shr $0x3,%r14 c: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 13: fc ff df 16: 41 80 3c 06 00 cmpb $0x0,(%r14,%rax,1) 1b: 74 0d je 0x2a 1d: 48 8d bc 24 00 02 00 lea 0x200(%rsp),%rdi 24: 00 25: e8 83 fe 11 00 callq 0x11fead * 2a: 48 89 9c 24 00 02 00 mov %rbx,0x200(%rsp) <-- trapping instruction 31: 00 32: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 39: fc ff df 3c: 41 rex.B 3d: 80 .byte 0x80 3e: 3c 06 cmp $0x6,%al