On 04/15/2015 12:57 AM, Alexei Starovoitov wrote:
Due to missing bounds check the DAG pass of the BPF verifier can corrupt the memory which can cause random crashes during program loading:[8.449451] BUG: unable to handle kernel paging request at ffffffffffffffff [8.451293] IP: [<ffffffff811de33d>] kmem_cache_alloc_trace+0x8d/0x2f0 [8.452329] Oops: 0000 [#1] SMP [8.452329] Call Trace: [8.452329] [<ffffffff8116cc82>] bpf_check+0x852/0x2000 [8.452329] [<ffffffff8116b7e4>] bpf_prog_load+0x1e4/0x310 [8.452329] [<ffffffff811b190f>] ? might_fault+0x5f/0xb0 [8.452329] [<ffffffff8116c206>] SyS_bpf+0x806/0xa30 Fixes: f1bca824dabb ("bpf: add search pruning optimization to verifier") Signed-off-by: Alexei Starovoitov <[email protected]>
As far as I can tell, looks good to me. Any other access to a next instruction elsewhere would be blocked from push_insn() with an error. Acked-by: Daniel Borkmann <[email protected]> -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
