================================================================== BUG: KASAN: use-after-free in tcp_retransmit_timer+0x2ef3/0x3360 net/ipv4/tcp_timer.c:511 Read of size 8 at addr ffff8880510a82c0 by task swapper/2/0 CPU: 2 PID: 0 Comm: swapper/2 Not tainted 5.18.0-syzkaller-10037-g7e284070abe5 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0xeb/0x495 mm/kasan/report.c:313 print_report mm/kasan/report.c:429 [inline] kasan_report.cold+0xf4/0x1c6 mm/kasan/report.c:491 tcp_retransmit_timer+0x2ef3/0x3360 net/ipv4/tcp_timer.c:511 tcp_write_timer_handler+0x5e6/0xbc0 net/ipv4/tcp_timer.c:622 tcp_write_timer+0xa2/0x2b0 net/ipv4/tcp_timer.c:642 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1519 [inline] __run_timers.part.0+0x679/0xa80 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+0x29b/0x9c2 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:1106 asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:default_idle+0xb/0x10 arch/x86/kernel/process.c:729 Code: ff ff ff 48 89 df e8 44 6d 4e f8 e9 55 ff ff ff 4c 89 e7 e8 37 6d 4e f8 eb 96 0f 1f 44 00 00 eb 07 0f 00 2d a7 fd 4d 00 fb f4 cc cc cc cc 41 55 41 54 55 48 89 fd 53 e8 02 b9 01 f8 e8 8d 11 RSP: 0018:ffffc9000047fe00 EFLAGS: 00000206 RAX: 0000000000350809 RBX: ffff888011521d80 RCX: ffffffff8975be91 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000002 R08: 0000000000000001 R09: ffff88802cc3b013 R10: ffffed1005987602 R11: 0000000000000000 R12: ffffed10022a43b0 R13: 0000000000000002 R14: ffffffff8dbb90d0 R15: 0000000000000000 default_idle_call+0x80/0xc0 kernel/sched/idle.c:109 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x401/0x590 kernel/sched/idle.c:303 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:400 start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:266 secondary_startup_64_no_verify+0xce/0xdb Allocated by task 3703: 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:436 [inline] __kasan_slab_alloc+0x90/0xc0 mm/kasan/common.c:469 kasan_slab_alloc include/linux/kasan.h:224 [inline] slab_post_alloc_hook mm/slab.h:750 [inline] slab_alloc_node mm/slub.c:3214 [inline] slab_alloc mm/slub.c:3222 [inline] __kmem_cache_alloc_lru mm/slub.c:3229 [inline] kmem_cache_alloc+0x204/0x3b0 mm/slub.c:3239 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:3135 __do_sys_unshare kernel/fork.c:3206 [inline] __se_sys_unshare kernel/fork.c:3204 [inline] __ia32_sys_unshare+0x2c/0x40 kernel/fork.c:3204 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x53/0x62 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+0x62e/0x1140 kernel/workqueue.c:1517 call_timer_fn+0x1a5/0x6b0 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+0x29b/0x9c2 kernel/softirq.c:571 Second to 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+0x62e/0x1140 kernel/workqueue.c:1517 call_timer_fn+0x1a5/0x6b0 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+0x29b/0x9c2 kernel/softirq.c:571 The buggy address belongs to the object at ffff8880510a8000 which belongs to the cache net_namespace of size 6784 The buggy address is located 704 bytes inside of 6784-byte region [ffff8880510a8000, ffff8880510a9a80) The buggy address belongs to the physical page: page:ffffea0001442a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880510a8000 pfn:0x510a8 head:ffffea0001442a00 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff88806e983981 flags: 0x4fff00000010200(slab|head|node=1|zone=1|lastcpupid=0x7ff) raw: 04fff00000010200 ffff888040005288 ffffea0001d87608 ffff888040042f00 raw: ffff8880510a8000 0000000000040000 00000001ffffffff ffff88806e983981 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 3703, tgid 3703 (syz-executor.2), ts 167272282295, free_ts 123866233944 prep_new_page mm/page_alloc.c:2436 [inline] get_page_from_freelist+0xbb3/0x3b80 mm/page_alloc.c:4178 __alloc_pages+0x1c7/0x510 mm/page_alloc.c:5406 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2272 alloc_slab_page mm/slub.c:1797 [inline] allocate_slab+0x26c/0x3c0 mm/slub.c:1942 new_slab mm/slub.c:2002 [inline] ___slab_alloc+0x985/0xd90 mm/slub.c:3002 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3089 slab_alloc_node mm/slub.c:3180 [inline] slab_alloc mm/slub.c:3222 [inline] __kmem_cache_alloc_lru mm/slub.c:3229 [inline] kmem_cache_alloc+0x360/0x3b0 mm/slub.c:3239 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:3135 __do_sys_unshare kernel/fork.c:3206 [inline] __se_sys_unshare kernel/fork.c:3204 [inline] __ia32_sys_unshare+0x2c/0x40 kernel/fork.c:3204 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x53/0x62 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1351 [inline] free_pcp_prepare+0x549/0xd20 mm/page_alloc.c:1401 free_unref_page_prepare mm/page_alloc.c:3323 [inline] free_unref_page+0x19/0x6a0 mm/page_alloc.c:3418 __put_page+0x17d/0x280 mm/swap.c:127 folio_put include/linux/mm.h:1200 [inline] put_page include/linux/mm.h:1233 [inline] __skb_frag_unref include/linux/skbuff.h:3480 [inline] skb_release_data+0x513/0x810 net/core/skbuff.c:672 skb_release_all net/core/skbuff.c:742 [inline] __kfree_skb net/core/skbuff.c:756 [inline] napi_consume_skb+0x256/0x340 net/core/skbuff.c:991 skb_defer_free_flush net/core/dev.c:6634 [inline] net_rx_action+0x342/0xd90 net/core/dev.c:6655 __do_softirq+0x29b/0x9c2 kernel/softirq.c:571 Memory state around the buggy address: ffff8880510a8180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880510a8200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880510a8280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880510a8300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880510a8380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess), 2 bytes skipped: 0: ff 48 89 decl -0x77(%rax) 3: df e8 fucomip %st(0),%st 5: 44 6d rex.R insl (%dx),%es:(%rdi) 7: 4e f8 rex.WRX clc 9: e9 55 ff ff ff jmpq 0xffffff63 e: 4c 89 e7 mov %r12,%rdi 11: e8 37 6d 4e f8 callq 0xf84e6d4d 16: eb 96 jmp 0xffffffae 18: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 1d: eb 07 jmp 0x26 1f: 0f 00 2d a7 fd 4d 00 verw 0x4dfda7(%rip) # 0x4dfdcd 26: fb sti 27: f4 hlt * 28: c3 retq <-- trapping instruction 29: cc int3 2a: cc int3 2b: cc int3 2c: cc int3 2d: 41 55 push %r13 2f: 41 54 push %r12 31: 55 push %rbp 32: 48 89 fd mov %rdi,%rbp 35: 53 push %rbx 36: e8 02 b9 01 f8 callq 0xf801b93d 3b: e8 .byte 0xe8 3c: 8d 11 lea (%rcx),%edx