kernel/linux.git/drivers/misc/lkdtm, branch v6.12.80

lkdtm: fortify: Fix potential NULL dereference on kmalloc failure

2025-10-29T13:08:52+00:00

[ Upstream commit 01c7344e21c2140e72282d9d16d79a61f840fc20 ] Add missing NULL pointer checks after kmalloc() calls in lkdtm_FORTIFY_STR_MEMBER() and lkdtm_FORTIFY_MEM_MEMBER() functions. Signed-off-by: Junjie Cao Link: https://lore.kernel.org/r/20250814060605.5264-1-junjie.cao@intel.com Signed-off-by: Kees Cook Signed-off-by: Sasha Levin

objtool, lkdtm: Obfuscate the do_nothing() pointer

2025-05-02T05:59:20+00:00

[ Upstream commit 05026ea01e95ffdeb0e5ac8fb7fb1b551e3a8726 ] If execute_location()'s memcpy of do_nothing() gets inlined and unrolled by the compiler, it copies one word at a time: mov 0x0(%rip),%rax R_X86_64_PC32 .text+0x1374 mov %rax,0x38(%rbx) mov 0x0(%rip),%rax R_X86_64_PC32 .text+0x136c mov %rax,0x30(%rbx) ... Those .text references point to the middle of the function, causing objtool to complain about their lack of ENDBR. Prevent that by resolving the function pointer at runtime rather than build time. This fixes the following warning: drivers/misc/lkdtm/lkdtm.o: warning: objtool: execute_location+0x23: relocation to !ENDBR: .text+0x1378 Reported-by: kernel test robot Signed-off-by: Josh Poimboeuf Signed-off-by: Ingo Molnar Reviewed-by: Kees Cook Cc: Arnd Bergmann Cc: Greg Kroah-Hartman Cc: Linus Torvalds Link: https://lore.kernel.org/r/30b9abffbddeb43c4f6320b1270fa9b4d74c54ed.1742852847.git.jpoimboe@kernel.org Closes: https://lore.kernel.org/oe-kbuild-all/202503191453.uFfxQy5R-lkp@intel.com/ Signed-off-by: Sasha Levin

Compiler Attributes: disable __counted_by for clang < 19.1.3

2024-12-05T13:02:45+00:00

commit f06e108a3dc53c0f5234d18de0bd224753db5019 upstream. This patch disables __counted_by for clang versions < 19.1.3 because of the two issues listed below. It does this by introducing CONFIG_CC_HAS_COUNTED_BY. 1. clang < 19.1.2 has a bug that can lead to __bdos returning 0: https://github.com/llvm/llvm-project/pull/110497 2. clang < 19.1.3 has a bug that can lead to __bdos being off by 4: https://github.com/llvm/llvm-project/pull/112636 Fixes: c8248faf3ca2 ("Compiler Attributes: counted_by: Adjust name and identifier expansion") Cc: stable@vger.kernel.org # 6.6.x: 16c31dd7fdf6: Compiler Attributes: counted_by: bump min gcc version Cc: stable@vger.kernel.org # 6.6.x: 2993eb7a8d34: Compiler Attributes: counted_by: fixup clang URL Cc: stable@vger.kernel.org # 6.6.x: 231dc3f0c936: lkdtm/bugs: Improve warning message for compilers without counted_by support Cc: stable@vger.kernel.org # 6.6.x Reported-by: Nathan Chancellor Closes: https://lore.kernel.org/all/20240913164630.GA4091534@thelio-3990X/ Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-lkp/202409260949.a1254989-oliver.sang@intel.com Link: https://lore.kernel.org/all/Zw8iawAF5W2uzGuh@archlinux/T/#m204c09f63c076586a02d194b87dffc7e81b8de7b Suggested-by: Nathan Chancellor Signed-off-by: Jan Hendrik Farr Reviewed-by: Nathan Chancellor Tested-by: Nathan Chancellor Reviewed-by: Miguel Ojeda Reviewed-by: Thorsten Blum Link: https://lore.kernel.org/r/20241029140036.577804-2-kernel@jfarr.cc Signed-off-by: Kees Cook Signed-off-by: Greg Kroah-Hartman

refcount: Report UAF for refcount_sub_and_test(0) when counter==0

2024-08-05T21:34:23+00:00

When a reference counter is at zero and refcount_sub_and_test() is invoked to subtract zero, the function accepts this request without any warning and returns true. This behavior does not seem ideal because the counter being already at zero indicates a use-after-free. Furthermore, returning true by refcount_sub_and_test() in this case potentially results in a double-free done by its caller. Modify the underlying function __refcount_sub_and_test() to warn about this case as a use-after-free and have it return false to avoid the potential double-free. Signed-off-by: Petr Pavlu Acked-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20240717130023.5675-1-petr.pavlu@suse.com Signed-off-by: Kees Cook

lkdtm/bugs: add test for hung smp_call_function_single()

2024-06-17T18:17:31+00:00

The CONFIG_CSD_LOCK_WAIT_DEBUG option enables debugging of hung smp_call_function*() calls (e.g. when the target CPU gets stuck within the callback function). Testing this option requires triggering such hangs. This patch adds an lkdtm test with a hung smp_call_function_single() callback, which can be used to test CONFIG_CSD_LOCK_WAIT_DEBUG and NMI backtraces (as CONFIG_CSD_LOCK_WAIT_DEBUG will attempt an NMI backtrace of the hung target CPU). On arm64 using pseudo-NMI, this looks like: | # mount -t debugfs none /sys/kernel/debug/ | # echo SMP_CALL_LOCKUP > /sys/kernel/debug/provoke-crash/DIRECT | lkdtm: Performing direct entry SMP_CALL_LOCKUP | smp: csd: Detected non-responsive CSD lock (#1) on CPU#1, waiting 5000000176 ns for CPU#00 __lkdtm_SMP_CALL_LOCKUP+0x0/0x8(0x0). | smp: csd: CSD lock (#1) handling this request. | Sending NMI from CPU 1 to CPUs 0: | NMI backtrace for cpu 0 | CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.9.0-rc4-00001-gfdfd281212ec #1 | Hardware name: linux,dummy-virt (DT) | pstate: 60401005 (nZCv daif +PAN -UAO -TCO -DIT +SSBS BTYPE=--) | pc : __lkdtm_SMP_CALL_LOCKUP+0x0/0x8 | lr : __flush_smp_call_function_queue+0x1b0/0x290 | sp : ffff800080003f30 | pmr_save: 00000060 | x29: ffff800080003f30 x28: ffffa4ce961a4900 x27: 0000000000000000 | x26: fff000003fcfa0c0 x25: ffffa4ce961a4900 x24: ffffa4ce959aa140 | x23: ffffa4ce959aa140 x22: 0000000000000000 x21: ffff800080523c40 | x20: 0000000000000000 x19: 0000000000000000 x18: fff05b31aa323000 | x17: fff05b31aa323000 x16: ffff800080000000 x15: 0000330fc3fe6b2c | x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000279 | x11: 0000000000000040 x10: fff000000302d0a8 x9 : fff000000302d0a0 | x8 : fff0000003400270 x7 : 0000000000000000 x6 : ffffa4ce9451b810 | x5 : 0000000000000000 x4 : fff05b31aa323000 x3 : ffff800080003f30 | x2 : fff05b31aa323000 x1 : ffffa4ce959aa140 x0 : 0000000000000000 | Call trace: | __lkdtm_SMP_CALL_LOCKUP+0x0/0x8 | generic_smp_call_function_single_interrupt+0x14/0x20 | ipi_handler+0xb8/0x178 | handle_percpu_devid_irq+0x84/0x130 | generic_handle_domain_irq+0x2c/0x44 | gic_handle_irq+0x118/0x240 | call_on_irq_stack+0x24/0x4c | do_interrupt_handler+0x80/0x84 | el1_interrupt+0x44/0xc0 | el1h_64_irq_handler+0x18/0x24 | el1h_64_irq+0x78/0x7c | default_idle_call+0x40/0x60 | do_idle+0x23c/0x2d0 | cpu_startup_entry+0x38/0x3c | kernel_init+0x0/0x1d8 | start_kernel+0x51c/0x608 | __primary_switched+0x80/0x88 | CPU: 1 PID: 128 Comm: sh Not tainted 6.9.0-rc4-00001-gfdfd281212ec #1 | Hardware name: linux,dummy-virt (DT) | Call trace: | dump_backtrace+0x90/0xe8 | show_stack+0x18/0x24 | dump_stack_lvl+0xac/0xe8 | dump_stack+0x18/0x24 | csd_lock_wait_toolong+0x268/0x338 | smp_call_function_single+0x1dc/0x2f0 | lkdtm_SMP_CALL_LOCKUP+0xcc/0xfc | lkdtm_do_action+0x1c/0x38 | direct_entry+0xbc/0x14c | full_proxy_write+0x60/0xb4 | vfs_write+0xd0/0x35c | ksys_write+0x70/0x104 | __arm64_sys_write+0x1c/0x28 | invoke_syscall+0x48/0x114 | el0_svc_common.constprop.0+0x40/0xe0 | do_el0_svc+0x1c/0x28 | el0_svc+0x38/0x108 | el0t_64_sync_handler+0x120/0x12c | el0t_64_sync+0x1a4/0x1a8 | smp: csd: Continued non-responsive CSD lock (#1) on CPU#1, waiting 10000064272 ns for CPU#00 __lkdtm_SMP_CALL_LOCKUP+0x0/0x8(0x0). | smp: csd: CSD lock (#1) handling this request. | smp: csd: Continued non-responsive CSD lock (#1) on CPU#1, waiting 15000064384 ns for CPU#00 __lkdtm_SMP_CALL_LOCKUP+0x0/0x8(0x0). | smp: csd: CSD lock (#1) handling this request. Signed-off-by: Mark Rutland Acked-by: Paul E. McKenney Cc: Kees Cook Link: https://lore.kernel.org/r/20240515120828.375585-1-mark.rutland@arm.com Signed-off-by: Kees Cook

Merge tag 'kbuild-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2024-05-18T19:39:20+00:00

Pull Kbuild updates from Masahiro Yamada: - Avoid 'constexpr', which is a keyword in C23 - Allow 'dtbs_check' and 'dt_compatible_check' run independently of 'dt_binding_check' - Fix weak references to avoid GOT entries in position-independent code generation - Convert the last use of 'optional' property in arch/sh/Kconfig - Remove support for the 'optional' property in Kconfig - Remove support for Clang's ThinLTO caching, which does not work with the .incbin directive - Change the semantics of $(src) so it always points to the source directory, which fixes Makefile inconsistencies between upstream and downstream - Fix 'make tar-pkg' for RISC-V to produce a consistent package - Provide reasonable default coverage for objtool, sanitizers, and profilers - Remove redundant OBJECT_FILES_NON_STANDARD, KASAN_SANITIZE, etc. - Remove the last use of tristate choice in drivers/rapidio/Kconfig - Various cleanups and fixes in Kconfig * tag 'kbuild-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (46 commits) kconfig: use sym_get_choice_menu() in sym_check_prop() rapidio: remove choice for enumeration kconfig: lxdialog: remove initialization with A_NORMAL kconfig: m/nconf: merge two item_add_str() calls kconfig: m/nconf: remove dead code to display value of bool choice kconfig: m/nconf: remove dead code to display children of choice members kconfig: gconf: show checkbox for choice correctly kbuild: use GCOV_PROFILE and KCSAN_SANITIZE in scripts/Makefile.modfinal Makefile: remove redundant tool coverage variables kbuild: provide reasonable defaults for tool coverage modules: Drop the .export_symbol section from the final modules kconfig: use menu_list_for_each_sym() in sym_check_choice_deps() kconfig: use sym_get_choice_menu() in conf_write_defconfig() kconfig: add sym_get_choice_menu() helper kconfig: turn defaults and additional prompt for choice members into error kconfig: turn missing prompt for choice members into error kconfig: turn conf_choice() into void function kconfig: use linked list in sym_set_changed() kconfig: gconf: use MENU_CHANGED instead of SYMBOL_CHANGED kconfig: gconf: remove debug code ...

Makefile: remove redundant tool coverage variables

2024-05-14T14:35:48+00:00

Now Kbuild provides reasonable defaults for objtool, sanitizers, and profilers. Remove redundant variables. Note: This commit changes the coverage for some objects: - include arch/mips/vdso/vdso-image.o into UBSAN, GCOV, KCOV - include arch/sparc/vdso/vdso-image-*.o into UBSAN - include arch/sparc/vdso/vma.o into UBSAN - include arch/x86/entry/vdso/extable.o into KASAN, KCSAN, UBSAN, GCOV, KCOV - include arch/x86/entry/vdso/vdso-image-*.o into KASAN, KCSAN, UBSAN, GCOV, KCOV - include arch/x86/entry/vdso/vdso32-setup.o into KASAN, KCSAN, UBSAN, GCOV, KCOV - include arch/x86/entry/vdso/vma.o into GCOV, KCOV - include arch/x86/um/vdso/vma.o into KASAN, GCOV, KCOV I believe these are positive effects because all of them are kernel space objects. Signed-off-by: Masahiro Yamada Reviewed-by: Kees Cook Tested-by: Roberto Sassu

lkdtm: Disable CFI checking for perms functions

2024-05-01T19:37:42+00:00

The EXEC_RODATA test plays a lot of tricks to live in the .rodata section, and once again ran into objtool's (completely reasonable) assumptions that executable code should live in an executable section. However, this manifested only under CONFIG_CFI_CLANG=y, as one of the .cfi_sites was pointing into the .rodata section. Since we're testing non-CFI execution properties in perms.c (and rodata.c), we can disable CFI for the involved functions, and remove the CFI arguments from rodata.c entirely. Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-lkp/202308301532.d7acf63e-oliver.sang@intel.com Fixes: 6342a20efbd8 ("objtool: Add elf_create_section_pair()") Link: https://lore.kernel.org/r/20240430234953.work.760-kees@kernel.org Signed-off-by: Kees Cook

lkdtm/bugs: Improve warning message for compilers without counted_by support

2024-03-22T23:25:31+00:00

The current message for telling the user that their compiler does not support the counted_by attribute in the FAM_BOUNDS test does not make much sense either grammatically or semantically. Fix it to make it correct in both aspects. Signed-off-by: Nathan Chancellor Reviewed-by: Gustavo A. R. Silva Link: https://lore.kernel.org/r/20240321-lkdtm-improve-lack-of-counted_by-msg-v1-1-0fbf7481a29c@kernel.org Signed-off-by: Kees Cook

Merge tag 'slab-for-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab

2024-03-13T03:14:54+00:00

Pull slab updates from Vlastimil Babka: - Freelist loading optimization (Chengming Zhou) When the per-cpu slab is depleted and a new one loaded from the cpu partial list, optimize the loading to avoid an irq enable/disable cycle. This results in a 3.5% performance improvement on the "perf bench sched messaging" test. - Kernel boot parameters cleanup after SLAB removal (Xiongwei Song) Due to two different main slab implementations we've had boot parameters prefixed either slab_ and slub_ with some later becoming an alias as both implementations gained the same functionality (i.e. slab_nomerge vs slub_nomerge). In order to eventually get rid of the implementation-specific names, the canonical and documented parameters are now all prefixed slab_ and the slub_ variants become deprecated but still working aliases. - SLAB_ kmem_cache creation flags cleanup (Vlastimil Babka) The flags had hardcoded #define values which became tedious and error-prone when adding new ones. Assign the values via an enum that takes care of providing unique bit numbers. Also deprecate SLAB_MEM_SPREAD which was only used by SLAB, so it's a no-op since SLAB removal. Assign it an explicit zero value. The removals of the flag usage are handled independently in the respective subsystems, with a final removal of any leftover usage planned for the next release. - Misc cleanups and fixes (Chengming Zhou, Xiaolei Wang, Zheng Yejian) Includes removal of unused code or function parameters and a fix of a memleak. * tag 'slab-for-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: slab: remove PARTIAL_NODE slab_state mm, slab: remove memcg_from_slab_obj() mm, slab: remove the corner case of inc_slabs_node() mm/slab: Fix a kmemleak in kmem_cache_destroy() mm, slab, kasan: replace kasan_never_merge() with SLAB_NO_MERGE mm, slab: use an enum to define SLAB_ cache creation flags mm, slab: deprecate SLAB_MEM_SPREAD flag mm, slab: fix the comment of cpu partial list mm, slab: remove unused object_size parameter in kmem_cache_flags() mm/slub: remove parameter 'flags' in create_kmalloc_caches() mm/slub: remove unused parameter in next_freelist_entry() mm/slub: remove full list manipulation for non-debug slab mm/slub: directly load freelist from cpu partial slab in the likely case mm/slub: make the description of slab_min_objects helpful in doc mm/slub: replace slub_$params with slab_$params in slub.rst mm/slub: unify all sl[au]b parameters with "slab_$param" Documentation: kernel-parameters: remove noaliencache