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Re: AddressSanitizer: heap-buffer-overflow in rl_kill_text
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From: |
Chet Ramey |
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Subject: |
Re: AddressSanitizer: heap-buffer-overflow in rl_kill_text |
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Date: |
Fri, 16 Jun 2017 14:11:02 -0400 |
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User-agent: |
Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:52.0) Gecko/20100101 Thunderbird/52.2.0 |
On 6/16/17 11:10 AM, Eduardo A. Bustamante López wrote:
> On Thu, Jun 15, 2017 at 09:42:41AM -0500, Eduardo Bustamante wrote:
>> Found by fuzzing `read -e' with AFL. The stacktrace reported by Address
>> Sanitizer is followed by the base64 encoded crashing input.
>>
>>
>> ==11018==ERROR: AddressSanitizer: heap-buffer-overflow on address
>> 0x60700000ccc0 at pc 0x559bb60f1be7 bp 0x7ffc36ec8710 sp 0x7ffc36ec8708
>> READ of size 8 at 0x60700000ccc0 thread T0
>> #0 0x559bb60f1be6 in _rl_copy_to_kill_ring
>> (/home/dualbus/src/gnu/bash-build/bash+0x23cbe6)
>
> Easy fix. When `rl_kill_ring_length == rl_max_kills (10)', all of the entries
> in the kill ring are shifted. The loop has an off-by-one error though.
This is one possible fix. There is also the asymmetry in the xrealloc
below.
--
``The lyf so short, the craft so long to lerne.'' - Chaucer
``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU chet@case.edu http://cnswww.cns.cwru.edu/~chet/