Re: KMSAN: uninit-value in ip_route_output_key_hash_rcu (4)
From: Eric Dumazet
Date: Thu Dec 07 2023 - 09:24:26 EST
On Thu, Dec 7, 2023 at 2:36 PM xingwei lee <xrivendell7@xxxxxxxxx> wrote:
>
> Hello
>
> I reproduced this bug in the latest upstream linux with repro.c and repro.txt
>
> When fuzzing the latest upstream linux 6.7-rc4, the following crash
> was triggered.
> HEAD commit: bee0e7762ad2c6025b9f5245c040fcc36ef2bde8
>
> If you fix this issue, please add the following tag to the commit:
> Reported-by: xingwei Lee <xrivendell7@xxxxxxxxx>
>
> console_log: https://gist.github.com/xrivendell7/195eb3c1946ea466f9d8f5977b90c6ed#file-console_log
> report: https://gist.github.com/xrivendell7/195eb3c1946ea466f9d8f5977b90c6ed#file-report
> kernel commit: bee0e7762ad2c6025b9f5245c040fcc36ef2bde8
> kernel config: https://syzkaller.appspot.com/text?tag=KernelConfig&x=ce27066613dacbb6
> repro.c: https://gist.github.com/xrivendell7/195eb3c1946ea466f9d8f5977b90c6ed#file-repro-c
> repro.txt: https://gist.github.com/xrivendell7/195eb3c1946ea466f9d8f5977b90c6ed#file-repro-txt
>
> In the lasted kernel: bee0e7762ad2c6025b9f5245c040fcc36ef2bde8 the
> crash likes below:
> [ 209.523497][ T8593] =====================================================
> [ 209.530316][ T8593] BUG: KMSAN: uninit-value in
> ip_route_output_key_hash_rcu+0x1ee8/0x3810
> [ 209.533357][ T8593] ip_route_output_key_hash_rcu+0x1ee8/0x3810
> [ 209.535524][ T8593] ip_route_output_flow+0x14f/0x320
> [ 209.537312][ T8593] ip_tunnel_xmit+0x1450/0x3e80
> [ 209.538995][ T8593] ipgre_xmit+0xd1c/0xe20
> [ 209.540511][ T8593] dev_hard_start_xmit+0x247/0xa10
> [ 209.542211][ T8593] __dev_queue_xmit+0x33b8/0x5130
> [ 209.543742][ T8593] __bpf_redirect+0xdd7/0x1600
> [ 209.545235][ T8593] bpf_clone_redirect+0x328/0x470
> [ 209.546807][ T8593] ___bpf_prog_run+0x2180/0xdb80
> [ 209.548288][ T8593] __bpf_prog_run512+0xb5/0xe0
> [ 209.549864][ T8593] bpf_test_run+0x482/0xb00
> [ 209.551178][ T8593] bpf_prog_test_run_skb+0x14e5/0x1f20
> [ 209.552612][ T8593] bpf_prog_test_run+0x6af/0xac0
> [ 209.553902][ T8593] __sys_bpf+0x649/0xd60
> [ 209.555000][ T8593] __x64_sys_bpf+0xa0/0xe0
> [ 209.556114][ T8593] do_syscall_64+0x44/0x110
> [ 209.557249][ T8593] entry_SYSCALL_64_after_hwframe+0x63/0x6b
> [ 209.558676][ T8593]
> [ 209.559232][ T8593] Uninit was stored to memory at:
> [ 209.560528][ T8593] ip_tunnel_xmit+0x1161/0x3e80
> [ 209.561676][ T8593] ipgre_xmit+0xd1c/0xe20
> [ 209.562711][ T8593] dev_hard_start_xmit+0x247/0xa10
> [ 209.563864][ T8593] __dev_queue_xmit+0x33b8/0x5130
> [ 209.564963][ T8593] __bpf_redirect+0xdd7/0x1600
> [ 209.566044][ T8593] bpf_clone_redirect+0x328/0x470
> [ 209.567151][ T8593] ___bpf_prog_run+0x2180/0xdb80
> [ 209.568184][ T8593] __bpf_prog_run512+0xb5/0xe0
> [ 209.569187][ T8593] bpf_test_run+0x482/0xb00
> [ 209.570201][ T8593] bpf_prog_test_run_skb+0x14e5/0x1f20
> [ 209.571308][ T8593] bpf_prog_test_run+0x6af/0xac0
> [ 209.572284][ T8593] __sys_bpf+0x649/0xd60
> [ 209.573131][ T8593] __x64_sys_bpf+0xa0/0xe0
> [ 209.574010][ T8593] do_syscall_64+0x44/0x110
> [ 209.574902][ T8593] entry_SYSCALL_64_after_hwframe+0x63/0x6b
> [ 209.576008][ T8593]
> [ 209.576456][ T8593] Uninit was created at:
> [ 209.577301][ T8593] slab_post_alloc_hook+0x129/0xa70
> [ 209.578284][ T8593] kmem_cache_alloc_node+0x5e9/0xb10
> [ 209.579233][ T8593] kmalloc_reserve+0x13d/0x4a0
> [ 209.580177][ T8593] pskb_expand_head+0x226/0x1a00
> [ 209.581096][ T8593] skb_ensure_writable+0x3d3/0x460
> [ 209.582015][ T8593] bpf_clone_redirect+0x17f/0x470
> [ 209.582963][ T8593] ___bpf_prog_run+0x2180/0xdb80
> [ 209.583859][ T8593] __bpf_prog_run512+0xb5/0xe0
> [ 209.584725][ T8593] bpf_test_run+0x482/0xb00
> [ 209.585556][ T8593] bpf_prog_test_run_skb+0x14e5/0x1f20
> [ 209.586527][ T8593] bpf_prog_test_run+0x6af/0xac0
> [ 209.587347][ T8593] __sys_bpf+0x649/0xd60
> [ 209.588058][ T8593] __x64_sys_bpf+0xa0/0xe0
> [ 209.588802][ T8593] do_syscall_64+0x44/0x110
> [ 209.589613][ T8593] entry_SYSCALL_64_after_hwframe+0x63/0x6b
Please double check the latest net tree.