================================================================== BUG: KASAN: use-after-free in tcp_retransmit_timer+0x2ef3/0x3360 net/ipv4/tcp_timer.c:511 Read of size 8 at addr ffff88807168d540 by task kworker/1:9/3763 CPU: 1 PID: 3763 Comm: kworker/1:9 Not tainted 5.18.0-rc3-syzkaller-01610-gac6a65868a5a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events linkwatch_event 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 b1 83 4b 00 5d be 03 00 00 00 e9 56 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:ffffc90003d3f7d0 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff88807a81ba00 RSI: ffffffff815fce68 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff900758c7 R10: ffffffff815fce5e R11: 0000000000000000 R12: ffffffff84efd940 R13: 0000000000000200 R14: ffffc90003d3f830 R15: dffffc0000000000 console_unlock+0x82e/0xdd0 kernel/printk/printk.c:2779 vprintk_emit+0x1b4/0x5f0 kernel/printk/printk.c:2272 vprintk+0x80/0x90 kernel/printk/printk_safe.c:50 _printk+0xba/0xed kernel/printk/printk.c:2293 addrconf_notify.cold+0x26/0x68 net/ipv6/addrconf.c:3612 notifier_call_chain+0xb5/0x200 kernel/notifier.c:84 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1943 netdev_state_change net/core/dev.c:1332 [inline] netdev_state_change+0x100/0x130 net/core/dev.c:1325 linkwatch_do_dev+0x10e/0x150 net/core/link_watch.c:168 __linkwatch_run_queue+0x243/0x6b0 net/core/link_watch.c:221 linkwatch_event+0x4a/0x60 net/core/link_watch.c:264 process_one_work+0x996/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 Allocated by task 3786: 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 Freed by task 4619: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track+0x21/0x30 mm/kasan/common.c:45 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free+0x166/0x1a0 mm/kasan/common.c:328 kasan_slab_free include/linux/kasan.h:200 [inline] slab_free_hook mm/slub.c:1728 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1754 slab_free mm/slub.c:3510 [inline] kmem_cache_free+0xdd/0x5a0 mm/slub.c:3527 net_free net/core/net_namespace.c:432 [inline] net_free net/core/net_namespace.c:428 [inline] cleanup_net+0x8ba/0xb00 net/core/net_namespace.c:615 process_one_work+0x996/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 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 ffff88807168d280 which belongs to the cache net_namespace of size 6784 The buggy address is located 704 bytes inside of 6784-byte region [ffff88807168d280, ffff88807168ed00) The buggy address belongs to the physical page: page:ffffea0001c5a200 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88807168b700 pfn:0x71688 head:ffffea0001c5a200 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff8880223ddf01 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000001 ffff888010dcd3c0 raw: ffff88807168b700 0000000080040003 00000001ffffffff ffff8880223ddf01 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 3631, tgid 3631 (syz-executor.0), ts 150848698253, free_ts 123637420975 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 __unfreeze_partials+0x17c/0x1a0 mm/slub.c:2523 qlink_free mm/kasan/quarantine.c:157 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0xa2/0xc0 mm/kasan/common.c:446 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] kmem_cache_alloc_node+0x255/0x3f0 mm/slub.c:3267 __alloc_skb+0x215/0x340 net/core/skbuff.c:414 alloc_skb_fclone include/linux/skbuff.h:1390 [inline] tcp_stream_alloc_skb+0x66/0x900 net/ipv4/tcp.c:862 tcp_sendmsg_locked+0xac8/0x2fb0 net/ipv4/tcp.c:1297 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1448 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:819 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:725 sock_write_iter+0x283/0x3c0 net/socket.c:1061 call_write_iter include/linux/fs.h:2050 [inline] new_sync_write+0x38a/0x560 fs/read_write.c:504 vfs_write+0x7c0/0xac0 fs/read_write.c:591 Memory state around the buggy address: ffff88807168d400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807168d480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807168d500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807168d580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807168d600: 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 b1 83 4b 00 jmpq 0x4b83ba 9: 5d pop %rbp a: be 03 00 00 00 mov $0x3,%esi f: e9 56 be 7e 02 jmpq 0x27ebe6a 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