03 Aug, 2016

1 commit

  • handle_object_size_mismatch() used %pk to format a kernel pointer with
    pr_err(). This seemed to be a misspelling for %pK, but using this to
    format a kernel pointer does not make much sence here.

    Therefore use %p instead, like in handle_missaligned_access().

    Link: http://lkml.kernel.org/r/20160730083010.11569-1-nicolas.iooss_linux@m4x.org
    Signed-off-by: Nicolas Iooss
    Acked-by: Andrey Ryabinin
    Cc: Joe Perches
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Nicolas Iooss
     

21 Jan, 2016

1 commit

  • UBSAN uses compile-time instrumentation to catch undefined behavior
    (UB). Compiler inserts code that perform certain kinds of checks before
    operations that could cause UB. If check fails (i.e. UB detected)
    __ubsan_handle_* function called to print error message.

    So the most of the work is done by compiler. This patch just implements
    ubsan handlers printing errors.

    GCC has this capability since 4.9.x [1] (see -fsanitize=undefined
    option and its suboptions).
    However GCC 5.x has more checkers implemented [2].
    Article [3] has a bit more details about UBSAN in the GCC.

    [1] - https://gcc.gnu.org/onlinedocs/gcc-4.9.0/gcc/Debugging-Options.html
    [2] - https://gcc.gnu.org/onlinedocs/gcc/Debugging-Options.html
    [3] - http://developerblog.redhat.com/2014/10/16/gcc-undefined-behavior-sanitizer-ubsan/

    Issues which UBSAN has found thus far are:

    Found bugs:

    * out-of-bounds access - 97840cb67ff5 ("netfilter: nfnetlink: fix
    insufficient validation in nfnetlink_bind")

    undefined shifts:

    * d48458d4a768 ("jbd2: use a better hash function for the revoke
    table")

    * 10632008b9e1 ("clockevents: Prevent shift out of bounds")

    * 'x << -1' shift in ext4 -
    http://lkml.kernel.org/r/

    * undefined rol32(0) -
    http://lkml.kernel.org/r/

    * undefined dirty_ratelimit calculation -
    http://lkml.kernel.org/r/

    * undefined roundown_pow_of_two(0) -
    http://lkml.kernel.org/r/

    * [WONTFIX] undefined shift in __bpf_prog_run -
    http://lkml.kernel.org/r/

    WONTFIX here because it should be fixed in bpf program, not in kernel.

    signed overflows:

    * 32a8df4e0b33f ("sched: Fix odd values in effective_load()
    calculations")

    * mul overflow in ntp -
    http://lkml.kernel.org/r/

    * incorrect conversion into rtc_time in rtc_time64_to_tm() -
    http://lkml.kernel.org/r/

    * unvalidated timespec in io_getevents() -
    http://lkml.kernel.org/r/

    * [NOTABUG] signed overflow in ktime_add_safe() -
    http://lkml.kernel.org/r/

    [akpm@linux-foundation.org: fix unused local warning]
    [akpm@linux-foundation.org: fix __int128 build woes]
    Signed-off-by: Andrey Ryabinin
    Cc: Peter Zijlstra
    Cc: Sasha Levin
    Cc: Randy Dunlap
    Cc: Rasmus Villemoes
    Cc: Jonathan Corbet
    Cc: Michal Marek
    Cc: Thomas Gleixner
    Cc: Ingo Molnar
    Cc: "H. Peter Anvin"
    Cc: Yury Gribov
    Cc: Dmitry Vyukov
    Cc: Konstantin Khlebnikov
    Cc: Kostya Serebryany
    Cc: Johannes Berg
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Andrey Ryabinin