kernel/drivers/misc/lkdtm_bugs.c, branch linux-4.16.y

lkdtm: include WARN format string

2017-11-18T00:10:01Z

In order to test the ordering of WARN format strings, actually include one in LKDTM. Link: http://lkml.kernel.org/r/1510100869-73751-2-git-send-email-keescook@chromium.org Signed-off-by: Kees Cook Cc: Arnd Bergmann Cc: Fengguang Wu Cc: Ingo Molnar Cc: Josh Poimboeuf Cc: Peter Zijlstra (Intel) Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55Z

Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

lkdtm: Add -fstack-protector-strong test

2017-08-15T19:27:35Z

There wasn't an LKDTM test to distinguish between -fstack-protector and -fstack-protector-strong in use. This adds CORRUPT_STACK_STRONG to see the difference. Also adjusts the stack-clobber value to 0xff so execution won't potentially jump into userspace when the stack protector is missing. Signed-off-by: Kees Cook

lkdtm: Test VMAP_STACK allocates leading/trailing guard pages

2017-08-04T20:04:21Z

Two new tests STACK_GUARD_PAGE_LEADING and STACK_GUARD_PAGE_TRAILING attempt to read the byte before and after, respectively, of the current stack frame, which should fault. Signed-off-by: Kees Cook

lkdtm: Provide more complete coverage for REFCOUNT tests

2017-07-26T21:38:03Z

The existing REFCOUNT_* LKDTM tests were designed only for testing a narrow portion of CONFIG_REFCOUNT_FULL. This moves the tests to their own file and expands their testing to poke each boundary condition. Since the protections (CONFIG_REFCOUNT_FULL and x86-fast) use different saturation values and reach-zero behavior, those have to be build-time set so the tests can actually validate things are happening at the right places. Notably, the x86-fast protection will fail REFCOUNT_INC_ZERO and REFCOUNT_ADD_ZERO since those conditions are not checked (only overflow is critical to protecting refcount_t). CONFIG_REFCOUNT_FULL will warn for each REFCOUNT_*_NEGATIVE test since it provides zero-pinning behaviors (which allows it to pass REFCOUNT_INC_ZERO and REFCOUNT_ADD_ZERO). Signed-off-by: Kees Cook

misc: lkdtm: Add volatile to intentional NULL pointer reference

2017-04-18T16:03:42Z

Add a volatile qualifier where a NULL pointer is deliberately dereferenced to trigger a panic. Without the volatile qualifier clang will issue the following warning: "indirection of non-volatile null pointer will be deleted, not trap [-Wnull-dereference]" and replace the pointer reference with a __builtin_trap() (which generates a ud2 instruction on x86_64). Signed-off-by: Michael Davidson Signed-off-by: Matthias Kaehlcke Acked-by: Kees Cook Signed-off-by: Greg Kroah-Hartman

lkdtm: add bad USER_DS test

2017-04-08T15:56:02Z

This adds CORRUPT_USER_DS to check that the get_fs() test on syscall return (via __VERIFY_PRE_USERMODE_STATE) still sees USER_DS. Since trying to deal with values other than USER_DS and KERNEL_DS across all architectures in a safe way is not sensible, this sets KERNEL_DS, but since that could be extremely dangerous if the protection is not present, it also raises SIGKILL for current, so that no matter what, the process will die. A successful test will be visible with a BUG(), like all the other LKDTM tests. Signed-off-by: Kees Cook Signed-off-by: Greg Kroah-Hartman

Merge tag 'char-misc-4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

2017-02-22T19:38:22Z

Pull char/misc driver updates from Greg KH: "Here is the big char/misc driver patchset for 4.11-rc1. Lots of different driver subsystems updated here: rework for the hyperv subsystem to handle new platforms better, mei and w1 and extcon driver updates, as well as a number of other "minor" driver updates. All of these have been in linux-next for a while with no reported issues" * tag 'char-misc-4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (169 commits) goldfish: Sanitize the broken interrupt handler x86/platform/goldfish: Prevent unconditional loading vmbus: replace modulus operation with subtraction vmbus: constify parameters where possible vmbus: expose hv_begin/end_read vmbus: remove conditional locking of vmbus_write vmbus: add direct isr callback mode vmbus: change to per channel tasklet vmbus: put related per-cpu variable together vmbus: callback is in softirq not workqueue binder: Add support for file-descriptor arrays binder: Add support for scatter-gather binder: Add extra size to allocator binder: Refactor binder_transact() binder: Support multiple /dev instances binder: Deal with contexts in debugfs binder: Support multiple context managers binder: Split flat_binder_object auxdisplay: ht16k33: remove private workqueue auxdisplay: ht16k33: rework input device initialization ...

lkdtm: Convert to refcount_t testing

2017-02-10T08:04:20Z

Since we'll be using refcount_t instead of atomic_t for refcounting, change the LKDTM tests to reflect the new interface and test conditions. Signed-off-by: Kees Cook Signed-off-by: Peter Zijlstra (Intel) Cc: Hans Liljestrand Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: arnd@arndb.de Cc: dhowells@redhat.com Cc: dwindsor@gmail.com Cc: elena.reshetova@intel.com Cc: gregkh@linuxfoundation.org Cc: h.peter.anvin@intel.com Cc: kernel-hardening@lists.openwall.com Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1486164412-7338-3-git-send-email-keescook@chromium.org Signed-off-by: Ingo Molnar

lkdtm: hide stack overflow warning for corrupt-stack test

2017-01-19T11:42:25Z

After the latest change to make sure the compiler actually does a memset, it is now smart enough to flag the stack overflow at compile time, at least with gcc-7.0: drivers/misc/lkdtm_bugs.c: In function 'lkdtm_CORRUPT_STACK': drivers/misc/lkdtm_bugs.c:88:144: warning: 'memset' writing 64 bytes into a region of size 8 overflows the destination [-Wstringop-overflow=] To outsmart the compiler again, this moves the memset into a noinline function where (for now) it doesn't see that we intentionally write broken code here. Fixes: c55d240003ae ("lkdtm: Prevent the compiler from optimising lkdtm_CORRUPT_STACK()") Signed-off-by: Arnd Bergmann Acked-by: Kees Cook Signed-off-by: Greg Kroah-Hartman