lkml.org 
[lkml]   [2012]   [Jul]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH] perf: prevent overflow in size calculation
    Date
    A large enough symbol size causes an overflow in the size parameter to the
    histogram allocation, leading to a segfault in symbol__inc_addr_samples later
    on when this histogram is accessed.

    In the case of being called via perf-report, this returns back and
    gracefully ignores the sample, eventually ignoring the chained return
    value of perf_session_deliver_event in flush_sample_queue.

    Signed-off-by: Cody Schafer <cody@linux.vnet.ibm.com>
    ---
    tools/perf/util/annotate.c | 7 ++++++-
    1 file changed, 6 insertions(+), 1 deletion(-)

    diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
    index 8069dfb..6f78f20 100644
    --- a/tools/perf/util/annotate.c
    +++ b/tools/perf/util/annotate.c
    @@ -426,8 +426,13 @@ int symbol__alloc_hist(struct symbol *sym)
    {
    struct annotation *notes = symbol__annotation(sym);
    const size_t size = symbol__size(sym);
    - size_t sizeof_sym_hist = (sizeof(struct sym_hist) + size * sizeof(u64));
    + size_t sizeof_sym_hist;

    + /* Check for overflow when calculating sizeof_sym_hist */
    + if (size > (SIZE_MAX / sizeof(u64)))
    + return -1;
    +
    + sizeof_sym_hist = (sizeof(struct sym_hist) + size * sizeof(u64));
    notes->src = zalloc(sizeof(*notes->src) + symbol_conf.nr_events * sizeof_sym_hist);
    if (notes->src == NULL)
    return -1;
    --
    1.7.9.5


    \
     
     \ /
      Last update: 2012-07-20 02:41    [W:0.024 / U:30.472 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site