| Message ID | 20221101222520.never.109-kees@kernel.org (mailing list archive) |
|---|---|
| Headers | show |
| Series | slab: Provide full coverage for __alloc_size attribute | expand |
On Tue, Nov 01, 2022 at 03:33:08PM -0700, Kees Cook wrote: > Hi, > > This is a series to work around a deficiency in GCC (>=11) and Clang > (<16) where the __alloc_size attribute does not apply to inlines. :( > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96503 > > This manifests as reduced overflow detection coverage for many allocation > sites under CONFIG_FORTIFY_SOURCE=y, where the allocation size was > not actually being propagated to __builtin_dynamic_object_size(). In > addition to working around the issue, expand use of __alloc_size (and > __realloc_size) to more places and provide KUnit tests to validate all > the covered allocator APIs. Hello Kees! It would appear that one of the macros you've added here is doing Bad Things^TM to allmodconfig on RISC-V since the 22nd: ../lib/fortify_kunit.c: In function 'alloc_size_kmalloc_const_test': ../lib/fortify_kunit.c:140:1: error: the frame size of 2384 bytes is larger than 2048 bytes [-Werror=frame-larger-than=] 140 | } \ | ^ ../lib/fortify_kunit.c:209:1: note: in expansion of macro 'DEFINE_ALLOC_SIZE_TEST_PAIR' 209 | DEFINE_ALLOC_SIZE_TEST_PAIR(kmalloc) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ cc1: all warnings being treated as errors CONFIG_GCC_VERSION=110100 CONFIG_AS_VERSION=23700 CONFIG_LD_VERSION=23700 The report came out of my CI (which I should have passed on sooner) so I do not have anything other than stderr - I can get you anything else you'd like/need though if you LMK. Thanks, Conor. > Kees Cook (6): > slab: Clean up SLOB vs kmalloc() definition > slab: Remove special-casing of const 0 size allocations > slab: Provide functional __alloc_size() hints to kmalloc_trace*() > string: Add __realloc_size hint to kmemdup() > driver core: Add __alloc_size hint to devm allocators > kunit/fortify: Validate __alloc_size attribute results > > include/linux/device.h | 7 +- > include/linux/fortify-string.h | 2 +- > include/linux/slab.h | 36 ++--- > include/linux/string.h | 2 +- > lib/Makefile | 1 + > lib/fortify_kunit.c | 255 +++++++++++++++++++++++++++++++++ > mm/slab_common.c | 14 ++ > 7 files changed, 296 insertions(+), 21 deletions(-) > > -- > 2.34.1 > >
On Tue, Nov 29, 2022, at 13:24, Conor Dooley wrote: > On Tue, Nov 01, 2022 at 03:33:08PM -0700, Kees Cook wrote: >> Hi, >> >> This is a series to work around a deficiency in GCC (>=11) and Clang >> (<16) where the __alloc_size attribute does not apply to inlines. :( >> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96503 >> >> This manifests as reduced overflow detection coverage for many allocation >> sites under CONFIG_FORTIFY_SOURCE=y, where the allocation size was >> not actually being propagated to __builtin_dynamic_object_size(). In >> addition to working around the issue, expand use of __alloc_size (and >> __realloc_size) to more places and provide KUnit tests to validate all >> the covered allocator APIs. > > Hello Kees! > > It would appear that one of the macros you've added here is doing Bad > Things^TM to allmodconfig on RISC-V since the 22nd: > > ../lib/fortify_kunit.c: In function 'alloc_size_kmalloc_const_test': > ../lib/fortify_kunit.c:140:1: error: the frame size of 2384 bytes is > larger than 2048 bytes [-Werror=frame-larger-than=] > 140 | } > \ > | ^ > ../lib/fortify_kunit.c:209:1: note: in expansion of macro > 'DEFINE_ALLOC_SIZE_TEST_PAIR' > 209 | DEFINE_ALLOC_SIZE_TEST_PAIR(kmalloc) > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ > cc1: all warnings being treated as errors > > CONFIG_GCC_VERSION=110100 > CONFIG_AS_VERSION=23700 > CONFIG_LD_VERSION=23700 > > The report came out of my CI (which I should have passed on sooner) so > I do not have anything other than stderr - I can get you anything else > you'd like/need though if you LMK. There is generally a conflict between kunit and the structleak gcc plugin, I think the Makefile needs a line like CFLAGS_fortify_kunit.o += $(DISABLE_STRUCTLEAK_PLUGIN) Arnd
On Tue, Nov 29, 2022 at 01:33:03PM +0100, Arnd Bergmann wrote: > On Tue, Nov 29, 2022, at 13:24, Conor Dooley wrote: > > On Tue, Nov 01, 2022 at 03:33:08PM -0700, Kees Cook wrote: > >> Hi, > >> > >> This is a series to work around a deficiency in GCC (>=11) and Clang > >> (<16) where the __alloc_size attribute does not apply to inlines. :( > >> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96503 > >> > >> This manifests as reduced overflow detection coverage for many allocation > >> sites under CONFIG_FORTIFY_SOURCE=y, where the allocation size was > >> not actually being propagated to __builtin_dynamic_object_size(). In > >> addition to working around the issue, expand use of __alloc_size (and > >> __realloc_size) to more places and provide KUnit tests to validate all > >> the covered allocator APIs. > > > > Hello Kees! > > > > It would appear that one of the macros you've added here is doing Bad > > Things^TM to allmodconfig on RISC-V since the 22nd: > > > > ../lib/fortify_kunit.c: In function 'alloc_size_kmalloc_const_test': > > ../lib/fortify_kunit.c:140:1: error: the frame size of 2384 bytes is > > larger than 2048 bytes [-Werror=frame-larger-than=] > > 140 | } > > \ > > | ^ > > ../lib/fortify_kunit.c:209:1: note: in expansion of macro > > 'DEFINE_ALLOC_SIZE_TEST_PAIR' > > 209 | DEFINE_ALLOC_SIZE_TEST_PAIR(kmalloc) > > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ > > cc1: all warnings being treated as errors > > > > CONFIG_GCC_VERSION=110100 > > CONFIG_AS_VERSION=23700 > > CONFIG_LD_VERSION=23700 > > > > The report came out of my CI (which I should have passed on sooner) so > > I do not have anything other than stderr - I can get you anything else > > you'd like/need though if you LMK. > > There is generally a conflict between kunit and the structleak > gcc plugin, I think the Makefile needs a line like > > CFLAGS_fortify_kunit.o += $(DISABLE_STRUCTLEAK_PLUGIN) Thanks for the report! I've taken Anders's patch for this now.