Re: [perf] yet another 32/64-bit range check failure

[Vince Weaver]

On Tue, 22 Apr 2014, Vince Weaver wrote:

> This is allowing events to be allocated memory but not being freed somehow
> before returning EINVAL (a memory leak).
> At least it looks like this is happening in the huge traces I have trying 
> to track down the perf_fuzzer memory corruption bug.

I can't find where the memory leak happens, but it looks like this in the 
trace:

[ 3524.626452] perf_fuz-1798    0.... 1271584315us : sys_enter: NR 298 (698e40, 706, ffffffff, f, 800000000000, 800000000000)
[ 3524.642312] perf_fuz-1798    0.... 1271584324us : kmalloc: call_site=ffffffff8113a575 ptr=ffff88007d5b0800 bytes_req=1272 bytes_alloc=2048 gfp_flags=GFP_KERNEL|GFP_ZERO
[ 3524.662598] perf_fuz-1798    0.... 1271584337us : sys_exit: NR 298 = -22

The call site for the kmalloc is in perf_event_alloc()

The memory is eventually freed as:

[ 3547.895534]   <idle>-0       0.Ns. 1271595088us : kfree: call_site=ffffffff811316aa ptr=ffff88007d5b0800


Vince
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