Re: KMSAN: uninit-value in ip_route_output_key_hash_rcu (4)
From: xingwei lee
Date: Thu Dec 07 2023 - 08:36:47 EST
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