Eric Dumazet <edumazet@xxxxxxxxxx> 于2022年8月24日周三 12:09写道： > > On Tue, Aug 23, 2022 at 9:00 PM Hao Sun <sunhao.th@xxxxxxxxx> wrote: > > > > Hi, > > > > Following crash can be triggered on: > > > > HEAD commit: 1c23f9e627a7 Linux 6.0-rc2 > > git tree: upstream > > console output: https://pastebin.com/raw/56RBVgyg > > kernel config: https://pastebin.com/raw/6VZXpdaB > > Syzlang reproducer: https://pastebin.com/raw/vpGfSssL > > > > Thanks for the report, but I think it is going to be hard to use. > > I have similar syzbot reports, and I usually wait for relevant SMC or > other layers > on top of TCP to be fixed. At least I wait for a bisection to complete. > > You could start a bisection, maybe it will give a valuable signal. > Thanks for the suggestion, but bisection is going to be extreamly slow on my pc. I generated a C reproducer from Syz prog, which can trigger the UAF with at most two runs. Hope this can help. C Reproducer: https://pastebin.com/raw/YgUtV6Kx > > Sorry that I don't have a C reproducer for this crash, I can reproduce > > the crash with the provided syzlang prog in 2 minutes. The prog can be > > executed by `syz-execprog -enable all repro.prog`, and I'm willing to > > provide more information if needed and test the proposed patches if > > any. > > > > ================================================================== > > BUG: KASAN: use-after-free in tcp_probe_timer net/ipv4/tcp_timer.c:378 [inline] > > BUG: KASAN: use-after-free in tcp_write_timer_handler > > net/ipv4/tcp_timer.c:624 [inline] > > BUG: KASAN: use-after-free in tcp_write_timer_handler+0x80e/0x860 > > net/ipv4/tcp_timer.c:594 > > Read of size 1 at addr ffff888103e786a5 by task swapper/3/0 > > > > CPU: 3 PID: 0 Comm: swapper/3 Not tainted 6.0.0-rc2-dirty #18 > > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS > > 1.13.0-1ubuntu1.1 04/01/2014 > > Call Trace: > > <IRQ> > > __dump_stack lib/dump_stack.c:88 [inline] > > dump_stack_lvl+0x57/0x7d lib/dump_stack.c:106 > > print_address_description mm/kasan/report.c:317 [inline] > > print_report.cold+0xe5/0x66d mm/kasan/report.c:433 > > kasan_report+0x8a/0x1b0 mm/kasan/report.c:495 > > tcp_probe_timer net/ipv4/tcp_timer.c:378 [inline] > > tcp_write_timer_handler net/ipv4/tcp_timer.c:624 [inline] > > tcp_write_timer_handler+0x80e/0x860 net/ipv4/tcp_timer.c:594 > > tcp_write_timer+0xa2/0x2b0 net/ipv4/tcp_timer.c:637 > > call_timer_fn+0x163/0x4a0 kernel/time/timer.c:1474 > > expire_timers kernel/time/timer.c:1519 [inline] > > __run_timers.part.0+0x562/0x940 kernel/time/timer.c:1790 > > __run_timers kernel/time/timer.c:1768 [inline] > > run_timer_softirq+0x9f/0x1a0 kernel/time/timer.c:1803 > > __do_softirq+0x1d0/0x908 kernel/softirq.c:571 > > invoke_softirq kernel/softirq.c:445 [inline] > > __irq_exit_rcu kernel/softirq.c:650 [inline] > > irq_exit_rcu+0xf2/0x130 kernel/softirq.c:662 > > sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1106 > > </IRQ> > > <TASK> > > asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649 > > RIP: 0010:default_idle+0xb/0x10 arch/x86/kernel/process.c:731 > > Code: ff e8 f9 d0 f2 f8 e9 5d fe ff ff e8 6f e6 fc ff cc cc cc cc cc > > cc cc cc cc cc cc cc cc cc cc eb 07 0f 00 2d 67 4b 63 00 fb f4 <c3> 0f > > 1f 40 00 41 54 be 08 00 00 00 53 65 48 8b 1c 25 80 6f 02 00 > > RSP: 0018:ffffc90000197de8 EFLAGS: 00000202 > > RAX: 00000000007404a1 RBX: 0000000000000003 RCX: ffffffff88bff659 > > RDX: 0000000000000000 RSI: ffffffff892bfee0 RDI: ffffffff89856740 > > RBP: 0000000000000003 R08: 0000000000000001 R09: ffffed1026ba698a > > R10: ffff888135d34c4b R11: ffffed1026ba6989 R12: 0000000000000003 > > R13: 0000000000000003 R14: ffffffff8d107c10 R15: 0000000000000000 > > default_idle_call+0xbd/0x420 kernel/sched/idle.c:109 > > cpuidle_idle_call kernel/sched/idle.c:191 [inline] > > do_idle+0x3f9/0x570 kernel/sched/idle.c:303 > > cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:400 > > start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:262 > > secondary_startup_64_no_verify+0xce/0xdb > > </TASK> > > > > Allocated by task 6749: > > 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:437 [inline] > > __kasan_slab_alloc+0x90/0xc0 mm/kasan/common.c:470 > > kasan_slab_alloc include/linux/kasan.h:224 [inline] > > slab_post_alloc_hook+0x4d/0x4f0 mm/slab.h:727 > > slab_alloc_node mm/slub.c:3243 [inline] > > slab_alloc mm/slub.c:3251 [inline] > > __kmem_cache_alloc_lru mm/slub.c:3258 [inline] > > kmem_cache_alloc+0x151/0x360 mm/slub.c:3268 > > kmem_cache_zalloc include/linux/slab.h:723 [inline] > > net_alloc net/core/net_namespace.c:404 [inline] > > copy_net_ns+0xea/0x660 net/core/net_namespace.c:459 > > create_new_namespaces.isra.0+0x330/0x8e0 kernel/nsproxy.c:110 > > unshare_nsproxy_namespaces+0x8d/0x1a0 kernel/nsproxy.c:227 > > ksys_unshare+0x314/0x6b0 kernel/fork.c:3183 > > __do_sys_unshare kernel/fork.c:3254 [inline] > > __se_sys_unshare kernel/fork.c:3252 [inline] > > __x64_sys_unshare+0x28/0x40 kernel/fork.c:3252 > > 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+0x63/0xcd > > > > Freed by task 10130: > > 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:367 [inline] > > ____kasan_slab_free mm/kasan/common.c:329 [inline] > > __kasan_slab_free+0x11d/0x1b0 mm/kasan/common.c:375 > > kasan_slab_free include/linux/kasan.h:200 [inline] > > slab_free_hook mm/slub.c:1754 [inline] > > slab_free_freelist_hook mm/slub.c:1780 [inline] > > slab_free mm/slub.c:3534 [inline] > > kmem_cache_free+0xf2/0x6b0 mm/slub.c:3551 > > net_free net/core/net_namespace.c:433 [inline] > > net_free+0x9b/0xd0 net/core/net_namespace.c:429 > > cleanup_net+0x7e8/0xa90 net/core/net_namespace.c:616 > > process_one_work+0x890/0x1400 kernel/workqueue.c:2289 > > worker_thread+0x552/0xe90 kernel/workqueue.c:2436 > > kthread+0x299/0x340 kernel/kthread.c:376 > > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 > > > > 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+0x45/0x320 kernel/workqueue.c:1358 > > __queue_work+0x3c3/0xeb0 kernel/workqueue.c:1517 > > call_timer_fn+0x163/0x4a0 kernel/time/timer.c:1474 > > expire_timers kernel/time/timer.c:1514 [inline] > > __run_timers.part.0+0x3c3/0x940 kernel/time/timer.c:1790 > > __do_softirq+0x1d0/0x908 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+0x45/0x320 kernel/workqueue.c:1358 > > __queue_work+0x3c3/0xeb0 kernel/workqueue.c:1517 > > call_timer_fn+0x163/0x4a0 kernel/time/timer.c:1474 > > expire_timers kernel/time/timer.c:1514 [inline] > > __run_timers.part.0+0x3c3/0x940 kernel/time/timer.c:1790 > > __do_softirq+0x1d0/0x908 kernel/softirq.c:571 > > > > The buggy address belongs to the object at ffff888103e78000 > > which belongs to the cache net_namespace of size 6784 > > The buggy address is located 1701 bytes inside of > > 6784-byte region [ffff888103e78000, ffff888103e79a80) > > > > The buggy address belongs to the physical page: > > page:ffffea00040f9e00 refcount:1 mapcount:0 mapping:0000000000000000 > > index:0xffff888103e7b700 pfn:0x103e78 > > head:ffffea00040f9e00 order:3 compound_mapcount:0 compound_pincount:0 > > flags: 0x57ff00000010200(slab|head|node=1|zone=2|lastcpupid=0x7ff) > > raw: 057ff00000010200 ffffea000447a008 ffffea000444e808 ffff888010e18f00 > > raw: ffff888103e7b700 0000000000040001 00000001ffffffff 0000000000000000 > > 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 6749, tgid 6749 (syz-executor.2), ts 101055637021, free_ts > > 100968720641 > > set_page_owner include/linux/page_owner.h:31 [inline] > > post_alloc_hook mm/page_alloc.c:2525 [inline] > > prep_new_page+0x2c6/0x350 mm/page_alloc.c:2532 > > get_page_from_freelist+0xae9/0x3a80 mm/page_alloc.c:4283 > > __alloc_pages+0x321/0x710 mm/page_alloc.c:5515 > > alloc_slab_page mm/slub.c:1824 [inline] > > allocate_slab mm/slub.c:1969 [inline] > > new_slab+0x246/0x3a0 mm/slub.c:2029 > > ___slab_alloc+0xa50/0x1060 mm/slub.c:3031 > > __slab_alloc.isra.0+0x4d/0xa0 mm/slub.c:3118 > > slab_alloc_node mm/slub.c:3209 [inline] > > slab_alloc mm/slub.c:3251 [inline] > > __kmem_cache_alloc_lru mm/slub.c:3258 [inline] > > kmem_cache_alloc+0x338/0x360 mm/slub.c:3268 > > kmem_cache_zalloc include/linux/slab.h:723 [inline] > > net_alloc net/core/net_namespace.c:404 [inline] > > copy_net_ns+0xea/0x660 net/core/net_namespace.c:459 > > create_new_namespaces.isra.0+0x330/0x8e0 kernel/nsproxy.c:110 > > unshare_nsproxy_namespaces+0x8d/0x1a0 kernel/nsproxy.c:227 > > ksys_unshare+0x314/0x6b0 kernel/fork.c:3183 > > __do_sys_unshare kernel/fork.c:3254 [inline] > > __se_sys_unshare kernel/fork.c:3252 [inline] > > __x64_sys_unshare+0x28/0x40 kernel/fork.c:3252 > > 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+0x63/0xcd > > page last free stack trace: > > reset_page_owner include/linux/page_owner.h:24 [inline] > > free_pages_prepare mm/page_alloc.c:1449 [inline] > > free_pcp_prepare+0x5ab/0xd00 mm/page_alloc.c:1499 > > free_unref_page_prepare mm/page_alloc.c:3380 [inline] > > free_unref_page+0x19/0x410 mm/page_alloc.c:3476 > > __unfreeze_partials+0x3f3/0x410 mm/slub.c:2548 > > qlink_free mm/kasan/quarantine.c:168 [inline] > > qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187 > > kasan_quarantine_reduce+0x13d/0x180 mm/kasan/quarantine.c:294 > > __kasan_slab_alloc+0xa2/0xc0 mm/kasan/common.c:447 > > kasan_slab_alloc include/linux/kasan.h:224 [inline] > > slab_post_alloc_hook+0x4d/0x4f0 mm/slab.h:727 > > slab_alloc_node mm/slub.c:3243 [inline] > > slab_alloc mm/slub.c:3251 [inline] > > __kmem_cache_alloc_lru mm/slub.c:3258 [inline] > > kmem_cache_alloc+0x151/0x360 mm/slub.c:3268 > > getname_flags fs/namei.c:139 [inline] > > getname_flags+0xb9/0x4e0 fs/namei.c:129 > > vfs_fstatat+0x35/0x70 fs/stat.c:254 > > vfs_lstat include/linux/fs.h:3282 [inline] > > __do_sys_newlstat+0x7f/0xd0 fs/stat.c:411 > > 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+0x63/0xcd > > > > Memory state around the buggy address: > > ffff888103e78580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ffff888103e78600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > >ffff888103e78680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ^ > > ffff888103e78700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ffff888103e78780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ================================================================== > > ---------------- > > Code disassembly (best guess), 1 bytes skipped: > > 0: e8 f9 d0 f2 f8 callq 0xf8f2d0fe > > 5: e9 5d fe ff ff jmpq 0xfffffe67 > > a: e8 6f e6 fc ff callq 0xfffce67e > > f: cc int3 > > 10: cc int3 > > 11: cc int3 > > 12: cc int3 > > 13: cc int3 > > 14: cc int3 > > 15: cc int3 > > 16: cc int3 > > 17: cc int3 > > 18: cc int3 > > 19: cc int3 > > 1a: cc int3 > > 1b: cc int3 > > 1c: cc int3 > > 1d: cc int3 > > 1e: eb 07 jmp 0x27 > > 20: 0f 00 2d 67 4b 63 00 verw 0x634b67(%rip) # 0x634b8e > > 27: fb sti > > 28: f4 hlt > > * 29: c3 retq <-- trapping instruction > > 2a: 0f 1f 40 00 nopl 0x0(%rax) > > 2e: 41 54 push %r12 > > 30: be 08 00 00 00 mov $0x8,%esi > > 35: 53 push %rbx > > 36: 65 48 8b 1c 25 80 6f mov %gs:0x26f80,%rbx > > 3d: 02 00
