================================================================== BUG: KASAN: use-after-free in tcp_retransmit_timer+0x6ee/0x2890 net/ipv4/tcp_timer.c:515 Read of size 8 at addr ffff88807d6d0258 by task syz-executor.3/5531 CPU: 1 PID: 5531 Comm: syz-executor.3 Not tainted 5.15.111-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:lock_acquire+0x252/0x4f0 kernel/locking/lockdep.c:5626 Code: 2b 00 74 08 4c 89 f7 e8 4c e4 66 00 f6 44 24 61 02 0f 85 84 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc9000346e700 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff9200068dcec RCX: 1ffff9200068dc8c RDX: dffffc0000000000 RSI: ffffffff8a8b0e00 RDI: ffffffff8ad85bc0 RBP: ffffc9000346e848 R08: dffffc0000000000 R09: fffffbfff1f78e21 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff9200068dce8 R13: dffffc0000000000 R14: ffffc9000346e760 R15: 0000000000000246 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:269 rcu_read_lock include/linux/rcupdate.h:696 [inline] ext4_get_group_desc+0x111/0x480 fs/ext4/balloc.c:284 __ext4_get_inode_loc+0x25e/0xcd0 fs/ext4/inode.c:4303 ext4_get_inode_loc fs/ext4/inode.c:4448 [inline] ext4_reserve_inode_write+0x1bf/0x3d0 fs/ext4/inode.c:5765 __ext4_mark_inode_dirty+0x1d6/0x860 fs/ext4/inode.c:5942 ext4_dirty_inode+0xbf/0x100 fs/ext4/inode.c:5979 __mark_inode_dirty+0x2fd/0xd60 fs/fs-writeback.c:2442 mark_inode_dirty include/linux/fs.h:2393 [inline] generic_write_end+0x232/0x440 fs/buffer.c:2204 ext4_da_write_end+0x72d/0x9e0 fs/ext4/inode.c:3094 generic_perform_write+0x3b7/0x5b0 mm/filemap.c:3787 ext4_buffered_write_iter+0x227/0x360 fs/ext4/file.c:268 ext4_file_write_iter+0x87c/0x1990 __kernel_write+0x5b1/0xa60 fs/read_write.c:539 __dump_emit+0x264/0x3a0 fs/coredump.c:875 dump_user_range+0x91/0x320 fs/coredump.c:949 elf_core_dump+0x3c7d/0x4570 fs/binfmt_elf.c:2285 do_coredump+0x1852/0x31e0 fs/coredump.c:826 get_signal+0xc06/0x14e0 kernel/signal.c:2875 arch_do_signal_or_restart+0xc3/0x1890 arch/x86/kernel/signal.c:865 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop+0x97/0x130 kernel/entry/common.c:172 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:208 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:314 exc_page_fault+0x342/0x740 arch/x86/mm/fault.c:1544 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:568 RIP: 0033:0x7ffac00a6171 Code: c4 28 c3 e8 f1 19 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 48 3d 01 f0 ff ff 73 01 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f RSP: 002b:0000553a21e21000 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007ffac01c5f80 RCX: 00007ffac00a6169 RDX: 0000000000000000 RSI: 0000553a21e21000 RDI: 00000000c0800400 RBP: 00007ffac0101ca1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007ffc2648accf R14: 00007ffabe618300 R15: 0000000000022000 Allocated by task 3533: 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 The buggy address belongs to the object at ffff88807d6d0000 which belongs to the cache net_namespace of size 6464 The buggy address is located 600 bytes inside of 6464-byte region [ffff88807d6d0000, ffff88807d6d1940) The buggy address belongs to the page: page:ffffea0001f5b400 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88807d6d0000 pfn:0x7d6d0 head:ffffea0001f5b400 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff88801881a841 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffff888011dc7288 ffff888011dc7288 ffff888011dc63c0 raw: ffff88807d6d0000 0000000000040002 00000001ffffffff ffff88801881a841 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 3533, ts 95408845830, free_ts 95404479463 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+0xf3/0x280 mm/slub.c:3233 sock_alloc_inode+0x17/0xb0 net/socket.c:303 alloc_inode fs/inode.c:236 [inline] new_inode_pseudo+0x60/0x210 fs/inode.c:937 sock_alloc net/socket.c:626 [inline] __sock_create+0x11f/0x8d0 net/socket.c:1431 sock_create net/socket.c:1518 [inline] __sys_socket+0x132/0x370 net/socket.c:1560 __do_sys_socket net/socket.c:1569 [inline] __se_sys_socket net/socket.c:1567 [inline] __x64_sys_socket+0x76/0x80 net/socket.c:1567 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 Memory state around the buggy address: ffff88807d6d0100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807d6d0180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807d6d0200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807d6d0280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807d6d0300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 2b 00 sub (%rax),%eax 2: 74 08 je 0xc 4: 4c 89 f7 mov %r14,%rdi 7: e8 4c e4 66 00 callq 0x66e458 c: f6 44 24 61 02 testb $0x2,0x61(%rsp) 11: 0f 85 84 01 00 00 jne 0x19b 17: 41 f7 c7 00 02 00 00 test $0x200,%r15d 1e: 74 01 je 0x21 20: fb sti 21: 48 c7 44 24 40 0e 36 movq $0x45e0360e,0x40(%rsp) 28: e0 45 * 2a: 4b c7 44 25 00 00 00 movq $0x0,0x0(%r13,%r12,1) <-- trapping instruction 31: 00 00 33: 43 c7 44 25 09 00 00 movl $0x0,0x9(%r13,%r12,1) 3a: 00 00 3c: 43 rex.XB 3d: c7 .byte 0xc7 3e: 44 rex.R 3f: 25 .byte 0x25