Date: Fri, 17 Sep 2021 14:21:04 +0000 From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 258559] tcsh can crash in morecore() due to 32-bit arithmetic Message-ID: <bug-258559-227@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D258559 Bug ID: 258559 Summary: tcsh can crash in morecore() due to 32-bit arithmetic Product: Base System Version: 13.0-RELEASE Hardware: Any OS: Any Status: New Severity: Affects Only Me Priority: --- Component: bin Assignee: bugs@FreeBSD.org Reporter: rtm@lcs.mit.edu tcsh's allocator uses 32-bit ints in pointer arithmetic in a way that's buggy on 64-bit machines: in morecore() in tc.alloc.c, if bucket is >=3D 28, then these lines aren't right: memtop =3D sbrk(1 << rnu); ... memtop +=3D (long) (1 << rnu); ... siz =3D 1 << (bucket + 3); The shifts yield 32-bit signed values, but the amounts of shift can be big enough that the results wrap. Here's a way to see the crash (it takes a few tens of seconds): % echo '$x:s<' | tcsh -f --=20 You are receiving this mail because: You are the assignee for the bug.=
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