user/sven/linux.git/include/linux/kernel.h, branch v4.14.281

hex2bin: make the function hex_to_bin constant-time

2022-05-12T10:17:06Z

commit e5be15767e7e284351853cbaba80cde8620341fb upstream. The function hex2bin is used to load cryptographic keys into device mapper targets dm-crypt and dm-integrity. It should take constant time independent on the processed data, so that concurrently running unprivileged code can't infer any information about the keys via microarchitectural convert channels. This patch changes the function hex_to_bin so that it contains no branches and no memory accesses. Note that this shouldn't cause performance degradation because the size of the new function is the same as the size of the old function (on x86-64) - and the new function causes no branch misprediction penalties. I compile-tested this function with gcc on aarch64 alpha arm hppa hppa64 i386 ia64 m68k mips32 mips64 powerpc powerpc64 riscv sh4 s390x sparc32 sparc64 x86_64 and with clang on aarch64 arm hexagon i386 mips32 mips64 powerpc powerpc64 s390x sparc32 sparc64 x86_64 to verify that there are no branches in the generated code. Signed-off-by: Mikulas Patocka Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

linux/kernel.h: fix overflow for DIV_ROUND_UP_ULL

2019-07-21T07:04:41Z

[ Upstream commit 8f9fab480c7a87b10bb5440b5555f370272a5d59 ] DIV_ROUND_UP_ULL adds the two arguments and then invokes DIV_ROUND_DOWN_ULL. But on a 32bit system the addition of two 32 bit values can overflow. DIV_ROUND_DOWN_ULL does it correctly and stashes the addition into a unsigned long long so cast the result to unsigned long long here to avoid the overflow condition. [akpm@linux-foundation.org: DIV_ROUND_UP_ULL must be an rval] Link: http://lkml.kernel.org/r/20190625100518.30753-1-vkoul@kernel.org Signed-off-by: Vinod Koul Reviewed-by: Andrew Morton Cc: Bjorn Andersson Cc: Randy Dunlap Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

linux/kernel.h: Use parentheses around argument in u64_to_user_ptr()

2019-05-10T15:53:10Z

[ Upstream commit a0fe2c6479aab5723239b315ef1b552673f434a3 ] Use parentheses around uses of the argument in u64_to_user_ptr() to ensure that the cast doesn't apply to part of the argument. There are existing uses of the macro of the form u64_to_user_ptr(A + B) which expands to (void __user *)(uintptr_t)A + B (the cast applies to the first operand of the addition, the addition is a pointer addition). This happens to still work as intended, the semantic difference doesn't cause a difference in behavior. But I want to use u64_to_user_ptr() with a ternary operator in the argument, like so: u64_to_user_ptr(A ? B : C) This currently doesn't work as intended. Signed-off-by: Jann Horn Signed-off-by: Borislav Petkov Reviewed-by: Mukesh Ojha Cc: Andrei Vagin Cc: Andrew Morton Cc: Dan Carpenter Cc: Greg Kroah-Hartman Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Jani Nikula Cc: Kees Cook Cc: Masahiro Yamada Cc: NeilBrown Cc: Peter Zijlstra Cc: Qiaowei Ren Cc: Thomas Gleixner Cc: x86-ml Link: https://lkml.kernel.org/r/20190329214652.258477-1-jannh@google.com Signed-off-by: Sasha Levin

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

linux/kernel.h: add/correct kernel-doc notation

2017-10-13T23:18:33Z

Add kernel-doc notation for some macros. Correct kernel-doc comments & typos for a few macros. Link: http://lkml.kernel.org/r/76fa1403-1511-be4c-e9c4-456b43edfad3@infradead.org Signed-off-by: Randy Dunlap Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

linux/kernel.h: move DIV_ROUND_DOWN_ULL() macro

2017-09-09T01:26:47Z

This macro is useful to avoid link error on 32-bit systems. We have the same definition in two drivers, so move it to include/linux/kernel.h While we are here, refactor DIV_ROUND_UP_ULL() by using DIV_ROUND_DOWN_ULL(). Link: http://lkml.kernel.org/r/1500945156-12907-1-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada Acked-by: Mark Brown Cc: Cyrille Pitchen Cc: Jaroslav Kysela Cc: Takashi Iwai Cc: Liam Girdwood Cc: Boris Brezillon Cc: Marek Vasut Cc: Brian Norris Cc: Richard Weinberger Cc: David Woodhouse Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

locking/refcounts, x86/asm: Implement fast refcount overflow protection

2017-08-17T08:40:26Z

This implements refcount_t overflow protection on x86 without a noticeable performance impact, though without the fuller checking of REFCOUNT_FULL. This is done by duplicating the existing atomic_t refcount implementation but with normally a single instruction added to detect if the refcount has gone negative (e.g. wrapped past INT_MAX or below zero). When detected, the handler saturates the refcount_t to INT_MIN / 2. With this overflow protection, the erroneous reference release that would follow a wrap back to zero is blocked from happening, avoiding the class of refcount-overflow use-after-free vulnerabilities entirely. Only the overflow case of refcounting can be perfectly protected, since it can be detected and stopped before the reference is freed and left to be abused by an attacker. There isn't a way to block early decrements, and while REFCOUNT_FULL stops increment-from-zero cases (which would be the state _after_ an early decrement and stops potential double-free conditions), this fast implementation does not, since it would require the more expensive cmpxchg loops. Since the overflow case is much more common (e.g. missing a "put" during an error path), this protection provides real-world protection. For example, the two public refcount overflow use-after-free exploits published in 2016 would have been rendered unexploitable: http://perception-point.io/2016/01/14/analysis-and-exploitation-of-a-linux-kernel-vulnerability-cve-2016-0728/ http://cyseclabs.com/page?n=02012016 This implementation does, however, notice an unchecked decrement to zero (i.e. caller used refcount_dec() instead of refcount_dec_and_test() and it resulted in a zero). Decrements under zero are noticed (since they will have resulted in a negative value), though this only indicates that a use-after-free may have already happened. Such notifications are likely avoidable by an attacker that has already exploited a use-after-free vulnerability, but it's better to have them reported than allow such conditions to remain universally silent. On first overflow detection, the refcount value is reset to INT_MIN / 2 (which serves as a saturation value) and a report and stack trace are produced. When operations detect only negative value results (such as changing an already saturated value), saturation still happens but no notification is performed (since the value was already saturated). On the matter of races, since the entire range beyond INT_MAX but before 0 is negative, every operation at INT_MIN / 2 will trap, leaving no overflow-only race condition. As for performance, this implementation adds a single "js" instruction to the regular execution flow of a copy of the standard atomic_t refcount operations. (The non-"and_test" refcount_dec() function, which is uncommon in regular refcount design patterns, has an additional "jz" instruction to detect reaching exactly zero.) Since this is a forward jump, it is by default the non-predicted path, which will be reinforced by dynamic branch prediction. The result is this protection having virtually no measurable change in performance over standard atomic_t operations. The error path, located in .text.unlikely, saves the refcount location and then uses UD0 to fire a refcount exception handler, which resets the refcount, handles reporting, and returns to regular execution. This keeps the changes to .text size minimal, avoiding return jumps and open-coded calls to the error reporting routine. Example assembly comparison: refcount_inc() before: .text: ffffffff81546149: f0 ff 45 f4 lock incl -0xc(%rbp) refcount_inc() after: .text: ffffffff81546149: f0 ff 45 f4 lock incl -0xc(%rbp) ffffffff8154614d: 0f 88 80 d5 17 00 js ffffffff816c36d3 ... .text.unlikely: ffffffff816c36d3: 48 8d 4d f4 lea -0xc(%rbp),%rcx ffffffff816c36d7: 0f ff (bad) These are the cycle counts comparing a loop of refcount_inc() from 1 to INT_MAX and back down to 0 (via refcount_dec_and_test()), between unprotected refcount_t (atomic_t), fully protected REFCOUNT_FULL (refcount_t-full), and this overflow-protected refcount (refcount_t-fast): 2147483646 refcount_inc()s and 2147483647 refcount_dec_and_test()s: cycles protections atomic_t 82249267387 none refcount_t-fast 82211446892 overflow, untested dec-to-zero refcount_t-full 144814735193 overflow, untested dec-to-zero, inc-from-zero This code is a modified version of the x86 PAX_REFCOUNT atomic_t overflow defense from the last public patch of PaX/grsecurity, based on my understanding of the code. Changes or omissions from the original code are mine and don't reflect the original grsecurity/PaX code. Thanks to PaX Team for various suggestions for improvement for repurposing this code to be a refcount-only protection. Signed-off-by: Kees Cook Reviewed-by: Josh Poimboeuf Cc: Alexey Dobriyan Cc: Andrew Morton Cc: Arnd Bergmann Cc: Christoph Hellwig Cc: David S. Miller Cc: Davidlohr Bueso Cc: Elena Reshetova Cc: Eric Biggers Cc: Eric W. Biederman Cc: Greg KH Cc: Hans Liljestrand Cc: James Bottomley Cc: Jann Horn Cc: Linus Torvalds Cc: Manfred Spraul Cc: Peter Zijlstra Cc: Rik van Riel Cc: Serge E. Hallyn Cc: Thomas Gleixner Cc: arozansk@redhat.com Cc: axboe@kernel.dk Cc: kernel-hardening@lists.openwall.com Cc: linux-arch Link: http://lkml.kernel.org/r/20170815161924.GA133115@beast Signed-off-by: Ingo Molnar

kernel.h: handle pointers to arrays better in container_of()

2017-07-12T23:25:59Z

If the first parameter of container_of() is a pointer to a non-const-qualified array type (and the third parameter names a non-const-qualified array member), the local variable __mptr will be defined with a const-qualified array type. In ISO C, these types are incompatible. They work as expected in GNU C, but some versions will issue warnings. For example, GCC 4.9 produces the warning "initialization from incompatible pointer type". Here is an example of where the problem occurs: ------------------------------------------------------- #include #include MODULE_LICENSE("GPL"); struct st { int a; char b[16]; }; static int __init example_init(void) { struct st t = { .a = 101, .b = "hello" }; char (*p)[16] = &t.b; struct st *x = container_of(p, struct st, b); printk(KERN_DEBUG "%p %p\n", (void *)&t, (void *)x); return 0; } static void __exit example_exit(void) { } module_init(example_init); module_exit(example_exit); ------------------------------------------------------- Building the module with gcc-4.9 results in these warnings (where '{m}' is the module source and '{k}' is the kernel source): ------------------------------------------------------- In file included from {m}/example.c:1:0: {m}/example.c: In function `example_init': {k}/include/linux/kernel.h:854:48: warning: initialization from incompatible pointer type const typeof( ((type *)0)->member ) *__mptr = (ptr); \ ^ {m}/example.c:14:17: note: in expansion of macro `container_of' struct st *x = container_of(p, struct st, b); ^ {k}/include/linux/kernel.h:854:48: warning: (near initialization for `x') const typeof( ((type *)0)->member ) *__mptr = (ptr); \ ^ {m}/example.c:14:17: note: in expansion of macro `container_of' struct st *x = container_of(p, struct st, b); ^ ------------------------------------------------------- Replace the type checking performed by the macro to avoid these warnings. Make sure `*(ptr)` either has type compatible with the member, or has type compatible with `void`, ignoring qualifiers. Raise compiler errors if this is not true. This is stronger than the previous behaviour, which only resulted in compiler warnings for a type mismatch. [arnd@arndb.de: fix new warnings for container_of()] Link: http://lkml.kernel.org/r/20170620200940.90557-1-arnd@arndb.de Link: http://lkml.kernel.org/r/20170525120316.24473-7-abbotti@mev.co.uk Signed-off-by: Ian Abbott Signed-off-by: Arnd Bergmann Acked-by: Michal Nazarewicz Acked-by: Kees Cook Cc: Hidehiro Kawai Cc: Borislav Petkov Cc: Rasmus Villemoes Cc: Johannes Berg Cc: Peter Zijlstra Cc: Alexander Potapenko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

init: Introduce SYSTEM_SCHEDULING state

2017-05-23T08:01:38Z

might_sleep() debugging and smp_processor_id() debugging should be active right after the scheduler starts working. The init task can invoke smp_processor_id() from preemptible context as it is pinned on the boot cpu until sched_smp_init() removes the pinning and lets it schedule on all non isolated cpus. Add a new state which allows to enable those checks earlier and add it to the xen do_poweroff() function. No functional change. Tested-by: Mark Rutland Signed-off-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Boris Ostrovsky Acked-by: Mark Rutland Cc: Greg Kroah-Hartman Cc: Juergen Gross Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Steven Rostedt Link: http://lkml.kernel.org/r/20170516184736.196214622@linutronix.de Signed-off-by: Ingo Molnar

Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6

2017-05-02T22:53:46Z

Pull crypto updates from Herbert Xu: "Here is the crypto update for 4.12: API: - Add batch registration for acomp/scomp - Change acomp testing to non-unique compressed result - Extend algorithm name limit to 128 bytes - Require setkey before accept(2) in algif_aead Algorithms: - Add support for deflate rfc1950 (zlib) Drivers: - Add accelerated crct10dif for powerpc - Add crc32 in stm32 - Add sha384/sha512 in ccp - Add 3des/gcm(aes) for v5 devices in ccp - Add Queue Interface (QI) backend support in caam - Add new Exynos RNG driver - Add ThunderX ZIP driver - Add driver for hardware random generator on MT7623 SoC" * 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (101 commits) crypto: stm32 - Fix OF module alias information crypto: algif_aead - Require setkey before accept(2) crypto: scomp - add support for deflate rfc1950 (zlib) crypto: scomp - allow registration of multiple scomps crypto: ccp - Change ISR handler method for a v5 CCP crypto: ccp - Change ISR handler method for a v3 CCP crypto: crypto4xx - rename ce_ring_contol to ce_ring_control crypto: testmgr - Allow ecb(cipher_null) in FIPS mode Revert "crypto: arm64/sha - Add constant operand modifier to ASM_EXPORT" crypto: ccp - Disable interrupts early on unload crypto: ccp - Use only the relevant interrupt bits hwrng: mtk - Add driver for hardware random generator on MT7623 SoC dt-bindings: hwrng: Add Mediatek hardware random generator bindings crypto: crct10dif-vpmsum - Fix missing preempt_disable() crypto: testmgr - replace compression known answer test crypto: acomp - allow registration of multiple acomps hwrng: n2 - Use devm_kcalloc() in n2rng_probe() crypto: chcr - Fix error handling related to 'chcr_alloc_shash' padata: get_next is never NULL crypto: exynos - Add new Exynos RNG driver ...