Date: Tue, 22 Oct 2019 11:04:54 -0700 From: Conrad Meyer <cem@freebsd.org> To: Alan Somers <asomers@freebsd.org> Cc: Andrew Turner <andrew@freebsd.org>, src-committers <src-committers@freebsd.org>, svn-src-all <svn-src-all@freebsd.org>, svn-src-head <svn-src-head@freebsd.org> Subject: Re: svn commit: r353640 - head/sys/kern Message-ID: <CAG6CVpUWDcqn3cEqtBzPxDWBS-7XtCFd7SxptPreA2hFuuDyOQ@mail.gmail.com> In-Reply-To: <CAOtMX2hfGrUtskf36H6r3kFu1JpjTs2yAU7rK5dRtAMp%2BXm=XQ@mail.gmail.com> References: <201910161321.x9GDL2ee021543@repo.freebsd.org> <CAOtMX2hfGrUtskf36H6r3kFu1JpjTs2yAU7rK5dRtAMp%2BXm=XQ@mail.gmail.com>
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Theoretically the information should be here, but it's still locked: https://admbugs.freebsd.org/show_bug.cgi?id=651 . On Tue, Oct 22, 2019 at 8:51 AM Alan Somers <asomers@freebsd.org> wrote: > > On Wed, Oct 16, 2019 at 7:21 AM Andrew Turner <andrew@freebsd.org> wrote: >> >> Author: andrew >> Date: Wed Oct 16 13:21:01 2019 >> New Revision: 353640 >> URL: https://svnweb.freebsd.org/changeset/base/353640 >> >> Log: >> Stop leaking information from the kernel through timespec >> >> The timespec struct holds a seconds value in a time_t and a nanoseconds >> value in a long. On most architectures these are the same size, however >> on 32-bit architectures other than i386 time_t is 8 bytes and long is >> 4 bytes. >> >> Most ABIs will then pad a struct holding an 8 byte and 4 byte value to >> 16 bytes with 4 bytes of padding. When copying one of these structs the >> compiler is free to copy the padding if it wishes. >> >> In this case the padding may contain kernel data that is then leaked to >> userspace. Fix this by copying the timespec elements rather than the >> entire struct. >> >> This doesn't affect Tier-1 architectures so no SA is expected. >> >> admbugs: 651 >> MFC after: 1 week >> Sponsored by: DARPA, AFRL > > > Good catch. Might I ask how you found it, or who reported it?
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