================================================================== BUG: KASAN: use-after-free in tcp_retransmit_timer+0x2ef3/0x3360 net/ipv4/tcp_timer.c:511 Read of size 8 at addr ffff88804c011e40 by task syz-executor.1/8149 CPU: 1 PID: 8149 Comm: syz-executor.1 Not tainted 5.18.0-rc3-syzkaller-01632-gc272e2591169 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 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:1421 expire_timers kernel/time/timer.c:1466 [inline] __run_timers.part.0+0x679/0xa80 kernel/time/timer.c:1737 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1750 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:166 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:200 Code: 48 89 ef 5d e9 81 83 4b 00 5d be 03 00 00 00 e9 16 be 7e 02 66 0f 1f 44 00 00 48 8b be a8 01 00 00 e8 b4 ff ff ff 31 c0 c3 90 <65> 8b 05 59 42 89 7e 89 c1 48 8b 34 24 81 e1 00 01 00 00 65 48 8b RSP: 0018:ffffc9000a3e7d80 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000200 RCX: 0000000000000000 RDX: ffff88801a90d700 RSI: ffffffff81da0ac1 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff90075967 R10: ffffffff81da0ab7 R11: 0000000000000001 R12: ffffc9000a3e7ea8 R13: ffff888042e77028 R14: 0000000000000000 R15: 0000000000000000 __seqprop_spinlock_sequence include/linux/seqlock.h:277 [inline] read_seqbegin include/linux/seqlock.h:840 [inline] d_lookup+0xa7/0x170 fs/dcache.c:2395 lookup_dcache+0x1e/0x130 fs/namei.c:1570 __lookup_hash+0x29/0x180 fs/namei.c:1593 do_unlinkat+0x281/0x650 fs/namei.c:4200 __do_sys_unlink fs/namei.c:4264 [inline] __se_sys_unlink fs/namei.c:4262 [inline] __x64_sys_unlink+0xc6/0x110 fs/namei.c:4262 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f144ae88a27 Code: 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 57 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffdba196888 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f144ae88a27 RDX: 00007ffdba1968c0 RSI: 00007ffdba1968c0 RDI: 00007ffdba196950 RBP: 00007ffdba196950 R08: 0000000000000001 R09: 00007ffdba196720 R10: 0000555556937913 R11: 0000000000000206 R12: 00007f144aee21f8 R13: 00007ffdba197a10 R14: 0000555556937810 R15: 00007ffdba197a50 Allocated by task 3630: 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:749 [inline] slab_alloc_node mm/slub.c:3217 [inline] slab_alloc mm/slub.c:3225 [inline] __kmem_cache_alloc_lru mm/slub.c:3232 [inline] kmem_cache_alloc+0x204/0x3b0 mm/slub.c:3242 kmem_cache_zalloc include/linux/slab.h:704 [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:3132 __do_sys_unshare kernel/fork.c:3203 [inline] __se_sys_unshare kernel/fork.c:3201 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3201 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae 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:1421 expire_timers kernel/time/timer.c:1461 [inline] __run_timers.part.0+0x4a3/0xa80 kernel/time/timer.c:1737 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0x152/0x1d0 kernel/time/timer.c:1752 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 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:1421 expire_timers kernel/time/timer.c:1461 [inline] __run_timers.part.0+0x4a3/0xa80 kernel/time/timer.c:1737 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0x152/0x1d0 kernel/time/timer.c:1752 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 The buggy address belongs to the object at ffff88804c011b80 which belongs to the cache net_namespace of size 6784 The buggy address is located 704 bytes inside of 6784-byte region [ffff88804c011b80, ffff88804c013600) The buggy address belongs to the physical page: page:ffffea0001300400 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88804c011b80 pfn:0x4c010 head:ffffea0001300400 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff88801fa8ab41 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0001b04200 dead000000000002 ffff888010dcd3c0 raw: ffff88804c011b80 0000000080040001 00000001ffffffff ffff88801fa8ab41 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 3628, tgid 3628 (syz-executor.4), ts 100147189353, free_ts 11489927733 prep_new_page mm/page_alloc.c:2441 [inline] get_page_from_freelist+0xba2/0x3e00 mm/page_alloc.c:4182 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5408 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2272 alloc_slab_page mm/slub.c:1799 [inline] allocate_slab+0x26c/0x3c0 mm/slub.c:1944 new_slab mm/slub.c:2004 [inline] ___slab_alloc+0x8df/0xf20 mm/slub.c:3005 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3092 slab_alloc_node mm/slub.c:3183 [inline] slab_alloc mm/slub.c:3225 [inline] __kmem_cache_alloc_lru mm/slub.c:3232 [inline] kmem_cache_alloc+0x360/0x3b0 mm/slub.c:3242 kmem_cache_zalloc include/linux/slab.h:704 [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:3132 __do_sys_unshare kernel/fork.c:3203 [inline] __se_sys_unshare kernel/fork.c:3201 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3201 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1356 [inline] free_pcp_prepare+0x549/0xd20 mm/page_alloc.c:1406 free_unref_page_prepare mm/page_alloc.c:3328 [inline] free_unref_page+0x19/0x6a0 mm/page_alloc.c:3423 free_contig_range+0xb1/0x180 mm/page_alloc.c:9418 destroy_args+0xa8/0x646 mm/debug_vm_pgtable.c:1018 debug_vm_pgtable+0x2a51/0x2ae3 mm/debug_vm_pgtable.c:1332 do_one_initcall+0x103/0x650 init/main.c:1298 do_initcall_level init/main.c:1371 [inline] do_initcalls init/main.c:1387 [inline] do_basic_setup init/main.c:1406 [inline] kernel_init_freeable+0x6b1/0x73a init/main.c:1613 kernel_init+0x1a/0x1d0 init/main.c:1502 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 Memory state around the buggy address: ffff88804c011d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88804c011d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88804c011e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88804c011e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88804c011f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 48 89 ef mov %rbp,%rdi 3: 5d pop %rbp 4: e9 81 83 4b 00 jmpq 0x4b838a 9: 5d pop %rbp a: be 03 00 00 00 mov $0x3,%esi f: e9 16 be 7e 02 jmpq 0x27ebe2a 14: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) 1a: 48 8b be a8 01 00 00 mov 0x1a8(%rsi),%rdi 21: e8 b4 ff ff ff callq 0xffffffda 26: 31 c0 xor %eax,%eax 28: c3 retq 29: 90 nop * 2a: 65 8b 05 59 42 89 7e mov %gs:0x7e894259(%rip),%eax # 0x7e89428a <-- trapping instruction 31: 89 c1 mov %eax,%ecx 33: 48 8b 34 24 mov (%rsp),%rsi 37: 81 e1 00 01 00 00 and $0x100,%ecx 3d: 65 gs 3e: 48 rex.W 3f: 8b .byte 0x8b