Re: [syzbot] [mptcp?] KASAN: slab-use-after-free Read in lock_timer_base

From: Matthieu Baerts
Date: Mon Sep 09 2024 - 11:31:36 EST

Next message: Paolo Bonzini: "Re: [PATCH 12/21] KVM: TDX: Set per-VM shadow_mmio_value to 0"
Previous message: Gary Guo: "Re: [PATCH v2 1/3] rust: Introduce HAVE_GENERATE_RUST_TARGET config option"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

Hello,

Thank you for the report.

On 03/09/2024 16:31, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 1934261d8974 Merge tag 'input-for-v6.11-rc5' of git://git...
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=10bf9943980000
> kernel config: https://syzkaller.appspot.com/x/.config?x=996585887acdadb3
> dashboard link: https://syzkaller.appspot.com/bug?extid=3a98aec25a4ab6a4d963
> compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
>
> Unfortunately, I don't have any reproducer for this issue yet.
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/d02c28e8dbf3/disk-1934261d.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/464d0e233034/vmlinux-1934261d.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/8735d78fb16a/bzImage-1934261d.xz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+3a98aec25a4ab6a4d963@xxxxxxxxxxxxxxxxxxxxxxxxx
>
> TCP: request_sock_subflow_v4: Possible SYN flooding on port [::]:20002. Sending cookies.
> ==================================================================
> BUG: KASAN: slab-use-after-free in lock_timer_base+0x1a7/0x240 kernel/time/timer.c:1052
> Read of size 4 at addr ffff888029b38e50 by task kworker/0:2/940
>
> CPU: 0 UID: 0 PID: 940 Comm: kworker/0:2 Not tainted 6.11.0-rc5-syzkaller-00219-g1934261d8974 #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
> Workqueue: events mptcp_worker
> Call Trace:
> <IRQ>
> __dump_stack lib/dump_stack.c:93 [inline]
> dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
> print_address_description mm/kasan/report.c:377 [inline]
> print_report+0x169/0x550 mm/kasan/report.c:488
> kasan_report+0x143/0x180 mm/kasan/report.c:601
> lock_timer_base+0x1a7/0x240 kernel/time/timer.c:1052
> __try_to_del_timer_sync+0xb5/0x340 kernel/time/timer.c:1506
> __timer_delete_sync+0x245/0x310 kernel/time/timer.c:1665
> del_timer_sync include/linux/timer.h:185 [inline]
> sk_stop_timer_sync+0x1c/0x90 net/core/sock.c:3454
> mptcp_pm_del_add_timer+0x18d/0x250 net/mptcp/pm_netlink.c:345
> mptcp_incoming_options+0x158d/0x2570 net/mptcp/options.c:1166
> tcp_data_queue+0xf5/0x76c0 net/ipv4/tcp_input.c:5206
> tcp_rcv_established+0xfba/0x2020 net/ipv4/tcp_input.c:6230
> tcp_v4_do_rcv+0x96d/0xc70 net/ipv4/tcp_ipv4.c:1911
> tcp_v4_rcv+0x2dc0/0x37f0 net/ipv4/tcp_ipv4.c:2346
> ip_protocol_deliver_rcu+0x22e/0x440 net/ipv4/ip_input.c:205
> ip_local_deliver_finish+0x341/0x5f0 net/ipv4/ip_input.c:233
> NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314
> NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314
> __netif_receive_skb_one_core net/core/dev.c:5661 [inline]
> __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5775
> process_backlog+0x662/0x15b0 net/core/dev.c:6108
> __napi_poll+0xcb/0x490 net/core/dev.c:6772
> napi_poll net/core/dev.c:6841 [inline]
> net_rx_action+0x89b/0x1240 net/core/dev.c:6963
> handle_softirqs+0x2c4/0x970 kernel/softirq.c:554
> do_softirq+0x11b/0x1e0 kernel/softirq.c:455
> </IRQ>
> <TASK>
> __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382
> mptcp_pm_send_ack net/mptcp/pm_netlink.c:496 [inline]
> mptcp_pm_nl_addr_send_ack+0x3ec/0x4e0 net/mptcp/pm_netlink.c:785
> mptcp_pm_nl_work+0x18e8/0x1fc0 net/mptcp/pm_netlink.c:924
> mptcp_worker+0x12f/0x1440 net/mptcp/protocol.c:2759
> process_one_work kernel/workqueue.c:3231 [inline]
> process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312
> worker_thread+0x86d/0xd10 kernel/workqueue.c:3389
> kthread+0x2f0/0x390 kernel/kthread.c:389
> ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
> ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
> </TASK>
>
> Allocated by task 940:
> kasan_save_stack mm/kasan/common.c:47 [inline]
> kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
> poison_kmalloc_redzone mm/kasan/common.c:370 [inline]
> __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387
> kasan_kmalloc include/linux/kasan.h:211 [inline]
> __kmalloc_cache_noprof+0x19c/0x2c0 mm/slub.c:4189
> kmalloc_noprof include/linux/slab.h:681 [inline]
> mptcp_pm_alloc_anno_list+0x14e/0x390 net/mptcp/pm_netlink.c:370
> mptcp_pm_create_subflow_or_signal_addr+0x1920/0x22c0 net/mptcp/pm_netlink.c:586
> mptcp_pm_nl_fully_established net/mptcp/pm_netlink.c:640 [inline]
> mptcp_pm_nl_work+0x19ae/0x1fc0 net/mptcp/pm_netlink.c:932
> mptcp_worker+0x12f/0x1440 net/mptcp/protocol.c:2759
> process_one_work kernel/workqueue.c:3231 [inline]
> process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312
> worker_thread+0x86d/0xd10 kernel/workqueue.c:3389
> kthread+0x2f0/0x390 kernel/kthread.c:389
> ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
> ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
>
> Freed by task 12966:
> kasan_save_stack mm/kasan/common.c:47 [inline]
> kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
> kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
> poison_slab_object+0xe0/0x150 mm/kasan/common.c:240
> __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256
> kasan_slab_free include/linux/kasan.h:184 [inline]
> slab_free_hook mm/slub.c:2252 [inline]
> slab_free mm/slub.c:4473 [inline]
> kfree+0x149/0x360 mm/slub.c:4594
> remove_anno_list_by_saddr+0x156/0x190 net/mptcp/pm_netlink.c:1466
> mptcp_pm_remove_addrs_and_subflows net/mptcp/pm_netlink.c:1687 [inline]
> mptcp_nl_remove_addrs_list net/mptcp/pm_netlink.c:1718 [inline]
> mptcp_pm_nl_flush_addrs_doit+0x664/0xd60 net/mptcp/pm_netlink.c:1759
> genl_family_rcv_msg_doit net/netlink/genetlink.c:1115 [inline]
> genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
> genl_rcv_msg+0xb14/0xec0 net/netlink/genetlink.c:1210
> netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2550
> genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
> netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline]
> netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1357
> netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1901
> sock_sendmsg_nosec net/socket.c:730 [inline]
> __sock_sendmsg+0x221/0x270 net/socket.c:745
> ____sys_sendmsg+0x525/0x7d0 net/socket.c:2597
> ___sys_sendmsg net/socket.c:2651 [inline]
> __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2680
> do_syscall_x64 arch/x86/entry/common.c:52 [inline]
> do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> The buggy address belongs to the object at ffff888029b38e00
> which belongs to the cache kmalloc-192 of size 192
> The buggy address is located 80 bytes inside of
> freed 192-byte region [ffff888029b38e00, ffff888029b38ec0)
>
> The buggy address belongs to the physical page:
> page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x29b38
> ksm flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
> page_type: 0xfdffffff(slab)
> raw: 00fff00000000000 ffff88801ac413c0 ffffea0000bd3380 dead000000000003
> raw: 0000000000000000 0000000080100010 00000001fdffffff 0000000000000000
> page dumped because: kasan: bad access detected
> page_owner tracks the page as allocated
> page last allocated via order 0, migratetype Unmovable, gfp_mask 0x352800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL|__GFP_THISNODE), pid 5573, tgid 5573 (cmp), ts 78576722831, free_ts 78537901249
> set_page_owner include/linux/page_owner.h:32 [inline]
> post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1493
> prep_new_page mm/page_alloc.c:1501 [inline]
> get_page_from_freelist+0x2e4c/0x2f10 mm/page_alloc.c:3439
> __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4695
> __alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
> alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
> alloc_slab_page+0x5f/0x120 mm/slub.c:2321
> allocate_slab+0x5a/0x2f0 mm/slub.c:2484
> new_slab mm/slub.c:2537 [inline]
> ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3723
> __slab_alloc+0x58/0xa0 mm/slub.c:3813
> __slab_alloc_node mm/slub.c:3866 [inline]
> slab_alloc_node mm/slub.c:4025 [inline]
> __do_kmalloc_node mm/slub.c:4157 [inline]
> __kmalloc_node_noprof+0x286/0x440 mm/slub.c:4164
> kmalloc_array_node_noprof include/linux/slab.h:788 [inline]
> alloc_slab_obj_exts mm/slub.c:1976 [inline]
> account_slab mm/slub.c:2447 [inline]
> allocate_slab+0xb6/0x2f0 mm/slub.c:2502
> new_slab mm/slub.c:2537 [inline]
> ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3723
> __slab_alloc+0x58/0xa0 mm/slub.c:3813
> __slab_alloc_node mm/slub.c:3866 [inline]
> slab_alloc_node mm/slub.c:4025 [inline]
> kmem_cache_alloc_noprof+0x1c1/0x2a0 mm/slub.c:4044
> vma_lock_alloc kernel/fork.c:445 [inline]
> vm_area_dup+0x61/0x290 kernel/fork.c:498
> __split_vma+0x1a9/0xc30 mm/mmap.c:2465
> do_vmi_align_munmap+0x433/0x18c0 mm/mmap.c:2676
> do_vmi_munmap+0x261/0x2f0 mm/mmap.c:2830
> page last free pid 5572 tgid 5572 stack trace:
> reset_page_owner include/linux/page_owner.h:25 [inline]
> free_pages_prepare mm/page_alloc.c:1094 [inline]
> free_unref_folios+0x103a/0x1b00 mm/page_alloc.c:2660
> folios_put_refs+0x76e/0x860 mm/swap.c:1039
> free_pages_and_swap_cache+0x5c8/0x690 mm/swap_state.c:335
> __tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline]
> tlb_batch_pages_flush mm/mmu_gather.c:149 [inline]
> tlb_flush_mmu_free mm/mmu_gather.c:366 [inline]
> tlb_flush_mmu+0x3a3/0x680 mm/mmu_gather.c:373
> tlb_finish_mmu+0xd4/0x200 mm/mmu_gather.c:465
> exit_mmap+0x44f/0xc80 mm/mmap.c:3425
> __mmput+0x115/0x390 kernel/fork.c:1345
> exit_mm+0x220/0x310 kernel/exit.c:571
> do_exit+0x9b2/0x27f0 kernel/exit.c:869
> do_group_exit+0x207/0x2c0 kernel/exit.c:1031
> __do_sys_exit_group kernel/exit.c:1042 [inline]
> __se_sys_exit_group kernel/exit.c:1040 [inline]
> __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1040
> x64_sys_call+0x2634/0x2640 arch/x86/include/generated/asm/syscalls_64.h:232
> do_syscall_x64 arch/x86/entry/common.c:52 [inline]
> do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> Memory state around the buggy address:
> ffff888029b38d00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff888029b38d80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
>> ffff888029b38e00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ^
> ffff888029b38e80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
> ffff888029b38f00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ==================================================================

I think this report is a duplicate of the following one:

https://syzkaller.appspot.com/bug?extid=3a98aec25a4ab6a4d963

Even if there is no reproducer, the call traces are very similar. I
guess it is then fine to mark them as duplicated.

#syz dup KASAN: slab-use-after-free Read in __timer_delete_sync

https://lore.kernel.org/000000000000b1b939062137e978@xxxxxxxxxx

Cheers,
Matt
--
Sponsored by the NGI0 Core fund.

Next message: Paolo Bonzini: "Re: [PATCH 12/21] KVM: TDX: Set per-VM shadow_mmio_value to 0"
Previous message: Gary Guo: "Re: [PATCH v2 1/3] rust: Introduce HAVE_GENERATE_RUST_TARGET config option"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]