================================================================== BUG: KASAN: use-after-free in tcp_retransmit_timer+0x6ee/0x2890 net/ipv4/tcp_timer.c:515 Read of size 8 at addr ffff888077159c98 by task syz-executor.3/13284 CPU: 0 PID: 13284 Comm: syz-executor.3 Not tainted 5.15.106-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:preempt_count_sub+0x0/0x160 kernel/sched/core.c:5508 Code: ff 48 c7 c1 88 4e e3 8d 80 e1 07 80 c1 03 38 c1 7c 80 48 c7 c7 88 4e e3 8d e8 ec 11 72 00 e9 6f ff ff ff 0f 1f 80 00 00 00 00 <41> 56 53 89 fb 48 c7 c0 a0 ef 3a 91 48 c1 e8 03 49 be 00 00 00 00 RSP: 0018:ffffc900032bed00 EFLAGS: 00000212 RAX: ffffc900032c0000 RBX: ffffc900032bedd0 RCX: ffffc900032bf918 RDX: dffffc0000000000 RSI: ffffc900032bf900 RDI: 0000000000000001 RBP: ffffc900032bf910 R08: ffffc900032bf900 R09: ffffc900032bee10 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffffffff1cc6ec3 R13: 1ffffffff1cc6ec3 R14: ffffc900032b8000 R15: ffffc900032bedc0 unwind_next_frame+0x1437/0x1fa0 arch/x86/kernel/unwind_orc.c:616 arch_stack_walk+0x10d/0x140 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122 save_stack+0xf6/0x1e0 mm/page_owner.c:119 __reset_page_owner+0x52/0x180 mm/page_owner.c:140 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_list+0x1f7/0x8e0 mm/page_alloc.c:3433 release_pages+0x1bb9/0x1f40 mm/swap.c:963 __pagevec_release+0x80/0xf0 mm/swap.c:983 pagevec_release include/linux/pagevec.h:81 [inline] truncate_inode_pages_range+0x48b/0x1290 mm/truncate.c:329 ext4_evict_inode+0x2ae/0x1100 fs/ext4/inode.c:224 evict+0x2a4/0x620 fs/inode.c:587 __dentry_kill+0x436/0x650 fs/dcache.c:582 dentry_kill+0xbb/0x290 dput+0x1f1/0x420 fs/dcache.c:888 __fput+0x5ec/0x890 fs/file_table.c:288 task_work_run+0x129/0x1a0 kernel/task_work.c:164 exit_task_work include/linux/task_work.h:32 [inline] do_exit+0x6a3/0x2480 kernel/exit.c:872 do_group_exit+0x144/0x310 kernel/exit.c:994 get_signal+0xc66/0x14e0 kernel/signal.c:2889 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_general_protection+0x358/0x4f0 arch/x86/kernel/traps.c:562 asm_exc_general_protection+0x22/0x30 arch/x86/include/asm/idtentry.h:562 RIP: 0033:0x7f04580e7171 Code: Unable to access opcode bytes at RIP 0x7f04580e7147. RSP: 002b:00000000200005b0 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007f0458206f80 RCX: 00007f04580e7169 RDX: 0000000020000100 RSI: 00000000200005b0 RDI: 000000000420a000 RBP: 00007f0458142ca1 R08: 0000000020000300 R09: 0000000020000300 R10: 00000000200007c0 R11: 0000000000000206 R12: 0000000000000000 R13: 00007ffe5f442d8f R14: 00007f0456659300 R15: 0000000000022000 Allocated by task 3607: 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 155: 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 ffff888077159a40 which belongs to the cache net_namespace of size 6464 The buggy address is located 600 bytes inside of 6464-byte region [ffff888077159a40, ffff88807715b380) The buggy address belongs to the page: page:ffffea0001dc5600 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88807715b480 pfn:0x77158 head:ffffea0001dc5600 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff888016781fc1 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0001dd3c00 0000000200000002 ffff888011dc63c0 raw: ffff88807715b480 0000000080040003 00000001ffffffff ffff888016781fc1 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 3610, ts 59593070365, free_ts 59569500225 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 kmem_cache_zalloc include/linux/slab.h:711 [inline] lsm_file_alloc security/security.c:574 [inline] security_file_alloc+0x24/0x120 security/security.c:1530 __alloc_file+0xc3/0x240 fs/file_table.c:106 alloc_empty_file+0x92/0x180 fs/file_table.c:150 path_openat+0xfc/0x2f20 fs/namei.c:3658 do_filp_open+0x21c/0x460 fs/namei.c:3699 do_sys_openat2+0x13b/0x500 fs/open.c:1211 Memory state around the buggy address: ffff888077159b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888077159c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888077159c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888077159d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888077159d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 48 c7 c1 88 4e e3 8d mov $0xffffffff8de34e88,%rcx 7: 80 e1 07 and $0x7,%cl a: 80 c1 03 add $0x3,%cl d: 38 c1 cmp %al,%cl f: 7c 80 jl 0xffffff91 11: 48 c7 c7 88 4e e3 8d mov $0xffffffff8de34e88,%rdi 18: e8 ec 11 72 00 callq 0x721209 1d: e9 6f ff ff ff jmpq 0xffffff91 22: 0f 1f 80 00 00 00 00 nopl 0x0(%rax) * 29: 41 56 push %r14 <-- trapping instruction 2b: 53 push %rbx 2c: 89 fb mov %edi,%ebx 2e: 48 c7 c0 a0 ef 3a 91 mov $0xffffffff913aefa0,%rax 35: 48 c1 e8 03 shr $0x3,%rax 39: 49 rex.WB 3a: be 00 00 00 00 mov $0x0,%esi