kernel/linux.git/drivers/misc/lkdtm/bugs.c, branch v6.4

drivers: lkdtm: fix clang -Wformat warning

2022-07-27T19:16:17+00:00

When building with Clang we encounter the following warning (ARCH=hexagon + CONFIG_FRAME_WARN=0): | ../drivers/misc/lkdtm/bugs.c:107:3: error: format specifies type | 'unsigned long' but the argument has type 'int' [-Werror,-Wformat] | REC_STACK_SIZE, recur_count); | ^~~~~~~~~~~~~~ Cast REC_STACK_SIZE to `unsigned long` to match format specifier `%lu` as well as maintain symmetry with `#define REC_STACK_SIZE (_AC(CONFIG_FRAME_WARN, UL) / 2)`. Link: https://github.com/ClangBuiltLinux/linux/issues/378 Reported-by: Nathan Chancellor Suggested-by: Nathan Chancellor Suggested-by: Nick Desaulniers Signed-off-by: Justin Stitt Reviewed-by: Nathan Chancellor Tested-by: Nathan Chancellor Acked-by: Kees Cook Fixes: 24cccab42c419 ("lkdtm/bugs: Adjust recursion test to avoid elision") Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20220721215706.4153027-1-justinstitt@google.com

lkdtm: Move crashtype definitions into each category

2022-04-12T23:16:48+00:00

It's long been annoying that to add a new LKDTM test one had to update lkdtm.h and core.c to get it "registered". Switch to a per-category list and update the crashtype walking code in core.c to handle it. This also means that all the lkdtm_* tests themselves can be static now. Cc: Arnd Bergmann Cc: Greg Kroah-Hartman Signed-off-by: Kees Cook

lkdtm/bugs: Don't expect thread termination without CONFIG_UBSAN_TRAP

2022-04-12T23:16:48+00:00

When you don't select CONFIG_UBSAN_TRAP, you get: # echo ARRAY_BOUNDS > /sys/kernel/debug/provoke-crash/DIRECT [ 102.265827] ================================================================================ [ 102.278433] UBSAN: array-index-out-of-bounds in drivers/misc/lkdtm/bugs.c:342:16 [ 102.287207] index 8 is out of range for type 'char [8]' [ 102.298722] ================================================================================ [ 102.313712] lkdtm: FAIL: survived array bounds overflow! [ 102.318770] lkdtm: Unexpected! This kernel (5.16.0-rc1-s3k-dev-01884-g720dcf79314a ppc) was built with CONFIG_UBSAN_BOUNDS=y It is not correct because when CONFIG_UBSAN_TRAP is not selected you can't expect array bounds overflow to kill the thread. Modify the logic so that when the kernel is built with CONFIG_UBSAN_BOUNDS but without CONFIG_UBSAN_TRAP, you get a warning about CONFIG_UBSAN_TRAP not been selected instead. This also require a fix of pr_expected_config(), otherwise the following error is encountered. CC drivers/misc/lkdtm/bugs.o drivers/misc/lkdtm/bugs.c: In function 'lkdtm_ARRAY_BOUNDS': drivers/misc/lkdtm/bugs.c:351:2: error: 'else' without a previous 'if' 351 | else | ^~~~ Fixes: c75be56e35b2 ("lkdtm/bugs: Add ARRAY_BOUNDS to selftests") Signed-off-by: Christophe Leroy Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/363b58690e907c677252467a94fe49444c80ea76.1649704381.git.christophe.leroy@csgroup.eu

lkdtm/bugs: Check for the NULL pointer after calling kmalloc

2022-04-12T23:11:49+00:00

As the possible failure of the kmalloc(), the not_checked and checked could be NULL pointer. Therefore, it should be better to check it in order to avoid the dereference of the NULL pointer. Also, we need to kfree the 'not_checked' and 'checked' to avoid the memory leak if fails. And since it is just a test, it may directly return without error number. Fixes: ae2e1aad3e48 ("drivers/misc/lkdtm/bugs.c: add arithmetic overflow and array bounds checks") Signed-off-by: Jiasheng Jiang Acked-by: Dan Carpenter Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20220120092936.1874264-1-jiasheng@iscas.ac.cn

lkdtm: avoid printk() in recursive_loop()

2021-12-16T23:54:37+00:00

The recursive_loop() function is intended as a diagnostic to ensure that exhausting the stack is caught and mitigated. Currently, it uses pr_info() to ensure that the function has side effects that the compiler cannot simply optimize away, so that the stack footprint does not get reduced inadvertently. The typical mitigation for stack overflow is to kill the task, and this overflow may occur inside the call to pr_info(), which means it could be holding the console lock when this happens. This means that the console lock is never going to be released again, preventing the diagnostic prints related to the stack overflow handling from being visible on the console. So let's replace the call to pr_info() with a call to memzero_explicit(), which is not a 'magic' function name like memset() or memcpy(), which the compiler may replace with plain loads and stores. To ensure that the stack frames are nested rather than tail-called, put the call to memzero_explicit() after the recursive call. Signed-off-by: Ard Biesheuvel Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20211007081235.382697-1-ardb@kernel.org

lkdtm/bugs: Check that a per-task stack canary exists

2021-10-25T07:13:46+00:00

Introduce REPORT_STACK_CANARY to check for differing stack canaries between two processes (i.e. that an architecture is correctly implementing per-task stack canaries), using the task_struct canary as the hint to locate in the stack. Requires that one of the processes being tested not be pid 1. Cc: Ard Biesheuvel Cc: Greg Kroah-Hartman Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20211022223826.330653-3-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman

lkdtm/fortify: Consolidate FORTIFY_SOURCE tests

2021-08-18T20:28:51+00:00

The FORTIFY_SOURCE tests were split between bugs.c and fortify.c. Move tests into fortify.c, standardize their naming, add CONFIG hints, and add them to the lkdtm selftests. Cc: Arnd Bergmann Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20210818174855.2307828-3-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman

lkdtm/bugs: Add ARRAY_BOUNDS to selftests

2021-08-18T20:28:51+00:00

Add CONFIG hints about why the ARRAY_BOUNDS test might fail, and similarly include the CONFIGs needed to pass the ARRAY_BOUNDS test via the selftests, and add to selftests. Cc: kernelci@groups.io Suggested-by: Guillaume Tucker Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20210818174855.2307828-2-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman

Merge tag 'char-misc-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

2021-07-05T20:42:16+00:00

Pull char / misc driver updates from Greg KH: "Here is the big set of char / misc and other driver subsystem updates for 5.14-rc1. Included in here are: - habanalabs driver updates - fsl-mc driver updates - comedi driver updates - fpga driver updates - extcon driver updates - interconnect driver updates - mei driver updates - nvmem driver updates - phy driver updates - pnp driver updates - soundwire driver updates - lots of other tiny driver updates for char and misc drivers This is looking more and more like the "various driver subsystems mushed together" tree... All of these have been in linux-next for a while with no reported issues" * tag 'char-misc-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (292 commits) mcb: Use DEFINE_RES_MEM() helper macro and fix the end address PNP: moved EXPORT_SYMBOL so that it immediately followed its function/variable bus: mhi: pci-generic: Add missing 'pci_disable_pcie_error_reporting()' calls bus: mhi: Wait for M2 state during system resume bus: mhi: core: Fix power down latency intel_th: Wait until port is in reset before programming it intel_th: msu: Make contiguous buffers uncached intel_th: Remove an unused exit point from intel_th_remove() stm class: Spelling fix nitro_enclaves: Set Bus Master for the NE PCI device misc: ibmasm: Modify matricies to matrices misc: vmw_vmci: return the correct errno code siox: Simplify error handling via dev_err_probe() fpga: machxo2-spi: Address warning about unused variable lkdtm/heap: Add init_on_alloc tests selftests/lkdtm: Enable various testable CONFIGs lkdtm: Add CONFIG hints in errors where possible lkdtm: Enable DOUBLE_FAULT on all architectures lkdtm/heap: Add vmalloc linear overflow test lkdtm/bugs: XFAIL UNALIGNED_LOAD_STORE_WRITE ...

lkdtm: Add CONFIG hints in errors where possible

2021-06-24T13:32:08+00:00

For various failure conditions, try to include some details about where to look for reasons about the failure. Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20210623203936.3151093-8-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman