On Fri, May 22, 2020 at 3:58 AM Walter Wu <walter-zh...@mediatek.com> wrote: > > This patchset improves KASAN reports by making them to have > call_rcu() call stack information. It is useful for programmers > to solve use-after-free or double-free memory issue. > > The KASAN report was as follows(cleaned up slightly): > > BUG: KASAN: use-after-free in kasan_rcu_reclaim+0x58/0x60 > > Freed by task 0: > kasan_save_stack+0x24/0x50 > kasan_set_track+0x24/0x38 > kasan_set_free_info+0x18/0x20 > __kasan_slab_free+0x10c/0x170 > kasan_slab_free+0x10/0x18 > kfree+0x98/0x270 > kasan_rcu_reclaim+0x1c/0x60 > > Last call_rcu(): > kasan_save_stack+0x24/0x50 > kasan_record_aux_stack+0xbc/0xd0 > call_rcu+0x8c/0x580 > kasan_rcu_uaf+0xf4/0xf8 > > Generic KASAN will record the last two call_rcu() call stacks and > print up to 2 call_rcu() call stacks in KASAN report. it is only > suitable for generic KASAN. > > This feature considers the size of struct kasan_alloc_meta and > kasan_free_meta, we try to optimize the structure layout and size > , let it get better memory consumption. > > [1]https://bugzilla.kernel.org/show_bug.cgi?id=198437 > [2]https://groups.google.com/forum/#!searchin/kasan-dev/better$20stack$20traces$20for$20rcu%7Csort:date/kasan-dev/KQsjT_88hDE/7rNUZprRBgAJ
Reviewed-by: Andrey Konovalov <andreyk...@google.com> for the series. Thanks! > > Changes since v2: > - remove new config option, default enable it in generic KASAN > - test this feature in SLAB/SLUB, it is pass. > - modify macro to be more clearly > - modify documentation > > Changes since v3: > - change recording from first/last to the last two call stacks > - move free track into kasan free meta > - init slab_free_meta on object slot creation > - modify documentation > > Changes since v4: > - change variable name to be more clearly > - remove the redundant condition > - remove init free meta-data and increasing object condition > > Changes since v5: > - add a macro KASAN_KMALLOC_FREETRACK in order to check whether > print free stack > - change printing message > - remove descriptions in Kocong.kasan > > Changes since v6: > - reuse print_stack() in print_track() > > Walter Wu (4): > rcu/kasan: record and print call_rcu() call stack > kasan: record and print the free track > kasan: add tests for call_rcu stack recording > kasan: update documentation for generic kasan > > Documentation/dev-tools/kasan.rst | 3 +++ > include/linux/kasan.h | 2 ++ > kernel/rcu/tree.c | 2 ++ > lib/test_kasan.c | 30 ++++++++++++++++++++++++++++++ > mm/kasan/common.c | 26 ++++---------------------- > mm/kasan/generic.c | 43 > +++++++++++++++++++++++++++++++++++++++++++ > mm/kasan/generic_report.c | 1 + > mm/kasan/kasan.h | 23 +++++++++++++++++++++-- > mm/kasan/quarantine.c | 1 + > mm/kasan/report.c | 54 > +++++++++++++++++++++++++++--------------------------- > mm/kasan/tags.c | 37 +++++++++++++++++++++++++++++++++++++ > 11 files changed, 171 insertions(+), 51 deletions(-) > > -- > You received this message because you are subscribed to the Google Groups > "kasan-dev" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to kasan-dev+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/kasan-dev/20200522015757.22267-1-walter-zh.wu%40mediatek.com.
