On Mon, May 11, 2020 at 4:24 AM Walter Wu <walter-zh.wu@xxxxxxxxxxxx> 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. Hi Walter, I am looking at this now. I've upload the change to gerrit [1] https://linux-review.googlesource.com/c/linux/kernel/git/torvalds/linux/+/2458 I am not capable enough to meaningfully review such changes in this format... [1] https://linux.googlesource.com/Documentation > The KASAN report was as follows(cleaned up slightly): > > BUG: KASAN: use-after-free in kasan_rcu_reclaim+0x58/0x60 > > Freed by task 0: > save_stack+0x24/0x50 > __kasan_slab_free+0x110/0x178 > kasan_slab_free+0x10/0x18 > kfree+0x98/0x270 > kasan_rcu_reclaim+0x1c/0x60 > rcu_core+0x8b4/0x10f8 > rcu_core_si+0xc/0x18 > efi_header_end+0x238/0xa6c > > First call_rcu() call stack: > save_stack+0x24/0x50 > kasan_record_callrcu+0xc8/0xd8 > call_rcu+0x190/0x580 > kasan_rcu_uaf+0x1d8/0x278 > > Last call_rcu() call stack: > (stack is not available) > > Generic KASAN will record first and last call_rcu() call stack > and print two call_rcu() call stack in KASAN report. > > This feature doesn't increase the cost of memory consumption. It is > only suitable for generic KASAN. > > [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 > > 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 > > Walter Wu (3): > rcu/kasan: record and print call_rcu() call stack > kasan: record and print the free track > kasan: update documentation for generic kasan > > Documentation/dev-tools/kasan.rst | 6 ++++++ > include/linux/kasan.h | 2 ++ > kernel/rcu/tree.c | 4 ++++ > lib/Kconfig.kasan | 2 ++ > mm/kasan/common.c | 26 ++++---------------------- > mm/kasan/generic.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ > mm/kasan/kasan.h | 23 +++++++++++++++++++++++ > mm/kasan/report.c | 47 +++++++++++++++++++++-------------------------- > mm/kasan/tags.c | 37 +++++++++++++++++++++++++++++++++++++ > 9 files changed, 149 insertions(+), 48 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+unsubscribe@xxxxxxxxxxxxxxxx. > To view this discussion on the web visit https://groups.google.com/d/msgid/kasan-dev/20200511022359.15063-1-walter-zh.wu%40mediatek.com.
