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From: "law at redhat dot com" <sourceware-bugzilla@sourceware.org> To: glibc-bugs@sources.redhat.com Subject: [Bug libc/14277] Pointer used after free'd Date: Thu, 21 Jun 2012 18:00:00 -0000 [thread overview] Message-ID: <bug-14277-131-9ZQO8QH1Rf@http.sourceware.org/bugzilla/> (raw) In-Reply-To: <bug-14277-131@http.sourceware.org/bugzilla/> http://sourceware.org/bugzilla/show_bug.cgi?id=14277 --- Comment #2 from law at redhat dot com 2012-06-21 18:00:06 UTC --- M_PERTURB does work for realloc (which just calls free internally). I can even verify that it puts my perturb bytes into the free'd memory. All fine and good. Unfortunately after installing my perturb byte, something else inside malloc decides to put the value 0 into the first 4 bytes of the free'd memory, overwriting my nice invalid pointer perturb byte ;( That happens to correspond to transmem_list->next. When we then try to use the value, it just looks like a null pointer, which the code assumes is the end of the list. So M_PERTURB isn't particularly helpful in generating a testcase for this bug. -- Configure bugmail: http://sourceware.org/bugzilla/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
next prev parent reply other threads:[~2012-06-21 18:00 UTC|newest] Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top 2012-06-21 16:05 [Bug libc/14277] New: " law at redhat dot com 2012-06-21 16:21 ` [Bug libc/14277] " joseph at codesourcery dot com 2012-06-21 18:00 ` law at redhat dot com [this message] 2012-06-21 19:24 ` aj at suse dot de 2012-06-21 19:27 ` aj at suse dot de 2012-06-21 23:34 ` bugdal at aerifal dot cx 2012-06-22 8:20 ` aj at suse dot de 2014-06-18 4:35 ` fweimer at redhat dot com
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