kernel/linux.git/lib, branch v4.15.6

swiotlb: suppress warning when __GFP_NOWARN is set

2018-02-22T14:39:54+00:00

commit d0bc0c2a31c95002d37c3cc511ffdcab851b3256 upstream. TTM tries to allocate coherent memory in chunks of 2MB first to improve TLB efficiency and falls back to allocating 4K pages if that fails. Suppress the warning when the 2MB allocations fails since there is a valid fall back path. Signed-off-by: Christian König Reported-by: Mike Galbraith Acked-by: Konrad Rzeszutek Wilk Bug: https://bugs.freedesktop.org/show_bug.cgi?id=104082 Signed-off-by: Christoph Hellwig Signed-off-by: Greg Kroah-Hartman

lib/ubsan: add type mismatch handler for new GCC/Clang

2018-02-16T19:06:59+00:00

commit 42440c1f9911b4b7b8ba3dc4e90c1197bc561211 upstream. UBSAN=y fails to build with new GCC/clang: arch/x86/kernel/head64.o: In function `sanitize_boot_params': arch/x86/include/asm/bootparam_utils.h:37: undefined reference to `__ubsan_handle_type_mismatch_v1' because Clang and GCC 8 slightly changed ABI for 'type mismatch' errors. Compiler now uses new __ubsan_handle_type_mismatch_v1() function with slightly modified 'struct type_mismatch_data'. Let's add new 'struct type_mismatch_data_common' which is independent from compiler's layout of 'struct type_mismatch_data'. And make __ubsan_handle_type_mismatch[_v1]() functions transform compiler-dependent type mismatch data to our internal representation. This way, we can support both old and new compilers with minimal amount of change. Link: http://lkml.kernel.org/r/20180119152853.16806-1-aryabinin@virtuozzo.com Signed-off-by: Andrey Ryabinin Reported-by: Sodagudi Prasad Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

lib/ubsan.c: s/missaligned/misaligned/

2018-02-16T19:06:59+00:00

commit b8fe1120b4ba342b4f156d24e952d6e686b20298 upstream. A vist from the spelling fairy. Cc: David Laight Cc: Andrey Ryabinin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

kasan: rework Kconfig settings

2018-02-16T19:06:53+00:00

commit e7c52b84fb18f08ce49b6067ae6285aca79084a8 upstream. We get a lot of very large stack frames using gcc-7.0.1 with the default -fsanitize-address-use-after-scope --param asan-stack=1 options, which can easily cause an overflow of the kernel stack, e.g. drivers/gpu/drm/i915/gvt/handlers.c:2434:1: warning: the frame size of 46176 bytes is larger than 3072 bytes drivers/net/wireless/ralink/rt2x00/rt2800lib.c:5650:1: warning: the frame size of 23632 bytes is larger than 3072 bytes lib/atomic64_test.c:250:1: warning: the frame size of 11200 bytes is larger than 3072 bytes drivers/gpu/drm/i915/gvt/handlers.c:2621:1: warning: the frame size of 9208 bytes is larger than 3072 bytes drivers/media/dvb-frontends/stv090x.c:3431:1: warning: the frame size of 6816 bytes is larger than 3072 bytes fs/fscache/stats.c:287:1: warning: the frame size of 6536 bytes is larger than 3072 bytes To reduce this risk, -fsanitize-address-use-after-scope is now split out into a separate CONFIG_KASAN_EXTRA Kconfig option, leading to stack frames that are smaller than 2 kilobytes most of the time on x86_64. An earlier version of this patch also prevented combining KASAN_EXTRA with KASAN_INLINE, but that is no longer necessary with gcc-7.0.1. All patches to get the frame size below 2048 bytes with CONFIG_KASAN=y and CONFIG_KASAN_EXTRA=n have been merged by maintainers now, so we can bring back that default now. KASAN_EXTRA=y still causes lots of warnings but now defaults to !COMPILE_TEST to disable it in allmodconfig, and it remains disabled in all other defconfigs since it is a new option. I arbitrarily raise the warning limit for KASAN_EXTRA to 3072 to reduce the noise, but an allmodconfig kernel still has around 50 warnings on gcc-7. I experimented a bit more with smaller stack frames and have another follow-up series that reduces the warning limit for 64-bit architectures to 1280 bytes (without CONFIG_KASAN). With earlier versions of this patch series, I also had patches to address the warnings we get with KASAN and/or KASAN_EXTRA, using a "noinline_if_stackbloat" annotation. That annotation now got replaced with a gcc-8 bugfix (see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81715) and a workaround for older compilers, which means that KASAN_EXTRA is now just as bad as before and will lead to an instant stack overflow in a few extreme cases. This reverts parts of commit 3f181b4d8652 ("lib/Kconfig.debug: disable -Wframe-larger-than warnings with KASAN=y"). Two patches in linux-next should be merged first to avoid introducing warnings in an allmodconfig build: 3cd890dbe2a4 ("media: dvb-frontends: fix i2c access helpers for KASAN") 16c3ada89cff ("media: r820t: fix r820t_write_reg for KASAN") Do we really need to backport this? I think we do: without this patch, enabling KASAN will lead to unavoidable kernel stack overflow in certain device drivers when built with gcc-7 or higher on linux-4.10+ or any version that contains a backport of commit c5caf21ab0cf8. Most people are probably still on older compilers, but it will get worse over time as they upgrade their distros. The warnings we get on kernels older than this should all be for code that uses dangerously large stack frames, though most of them do not cause an actual stack overflow by themselves.The asan-stack option was added in linux-4.0, and commit 3f181b4d8652 ("lib/Kconfig.debug: disable -Wframe-larger-than warnings with KASAN=y") effectively turned off the warning for allmodconfig kernels, so I would like to see this fix backported to any kernels later than 4.0. I have done dozens of fixes for individual functions with stack frames larger than 2048 bytes with asan-stack, and I plan to make sure that all those fixes make it into the stable kernels as well (most are already there). Part of the complication here is that asan-stack (from 4.0) was originally assumed to always require much larger stacks, but that turned out to be a combination of multiple gcc bugs that we have now worked around and fixed, but sanitize-address-use-after-scope (from v4.10) has a much higher inherent stack usage and also suffers from at least three other problems that we have analyzed but not yet fixed upstream, each of them makes the stack usage more severe than it should be. Link: http://lkml.kernel.org/r/20171221134744.2295529-1-arnd@arndb.de Signed-off-by: Arnd Bergmann Acked-by: Andrey Ryabinin Cc: Mauro Carvalho Chehab Cc: Andrey Ryabinin Cc: Alexander Potapenko Cc: Dmitry Vyukov Cc: Andrey Konovalov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

test_firmware: fix missing unlock on error in config_num_requests_store()

2018-02-03T16:58:43+00:00

commit a5e1923356505e46476c2fb518559b7a4d9d25b1 upstream. Add the missing unlock before return from function config_num_requests_store() in the error handling case. Fixes: c92316bf8e94 ("test_firmware: add batched firmware tests") Signed-off-by: Wei Yongjun Signed-off-by: Greg Kroah-Hartman

Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

2018-01-10T16:17:21+00:00

Daniel Borkmann says: ==================== pull-request: bpf 2018-01-09 The following pull-request contains BPF updates for your *net* tree. The main changes are: 1) Prevent out-of-bounds speculation in BPF maps by masking the index after bounds checks in order to fix spectre v1, and add an option BPF_JIT_ALWAYS_ON into Kconfig that allows for removing the BPF interpreter from the kernel in favor of JIT-only mode to make spectre v2 harder, from Alexei. 2) Remove false sharing of map refcount with max_entries which was used in spectre v1, from Daniel. 3) Add a missing NULL psock check in sockmap in order to fix a race, from John. 4) Fix test_align BPF selftest case since a recent change in verifier rejects the bit-wise arithmetic on pointers earlier but test_align update was missing, from Alexei. ==================== Signed-off-by: David S. Miller

bpf: introduce BPF_JIT_ALWAYS_ON config

2018-01-09T21:25:26+00:00

The BPF interpreter has been used as part of the spectre 2 attack CVE-2017-5715. A quote from goolge project zero blog: "At this point, it would normally be necessary to locate gadgets in the host kernel code that can be used to actually leak data by reading from an attacker-controlled location, shifting and masking the result appropriately and then using the result of that as offset to an attacker-controlled address for a load. But piecing gadgets together and figuring out which ones work in a speculation context seems annoying. So instead, we decided to use the eBPF interpreter, which is built into the host kernel - while there is no legitimate way to invoke it from inside a VM, the presence of the code in the host kernel's text section is sufficient to make it usable for the attack, just like with ordinary ROP gadgets." To make attacker job harder introduce BPF_JIT_ALWAYS_ON config option that removes interpreter from the kernel in favor of JIT-only mode. So far eBPF JIT is supported by: x64, arm64, arm32, sparc64, s390, powerpc64, mips64 The start of JITed program is randomized and code page is marked as read-only. In addition "constant blinding" can be turned on with net.core.bpf_jit_harden v2->v3: - move __bpf_prog_ret0 under ifdef (Daniel) v1->v2: - fix init order, test_bpf and cBPF (Daniel's feedback) - fix offloaded bpf (Jakub's feedback) - add 'return 0' dummy in case something can invoke prog->bpf_func - retarget bpf tree. For bpf-next the patch would need one extra hunk. It will be sent when the trees are merged back to net-next Considered doing: int bpf_jit_enable __read_mostly = BPF_EBPF_JIT_DEFAULT; but it seems better to land the patch as-is and in bpf-next remove bpf_jit_enable global variable from all JITs, consolidate in one place and remove this jit_init() function. Signed-off-by: Alexei Starovoitov Signed-off-by: Daniel Borkmann

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

2018-01-05T20:10:06+00:00

Pull crypto fixes from Herbert Xu: "This fixes the following issues: - racy use of ctx->rcvused in af_alg - algif_aead crash in chacha20poly1305 - freeing bogus pointer in pcrypt - build error on MIPS in mpi - memory leak in inside-secure - memory overwrite in inside-secure - NULL pointer dereference in inside-secure - state corruption in inside-secure - build error without CRYPTO_GF128MUL in chelsio - use after free in n2" * 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: crypto: inside-secure - do not use areq->result for partial results crypto: inside-secure - fix request allocations in invalidation path crypto: inside-secure - free requests even if their handling failed crypto: inside-secure - per request invalidation lib/mpi: Fix umul_ppmm() for MIPS64r6 crypto: pcrypt - fix freeing pcrypt instances crypto: n2 - cure use after free crypto: af_alg - Fix race around ctx->rcvused by making it atomic_t crypto: chacha20poly1305 - validate the digest size crypto: chelsio - select CRYPTO_GF128MUL

Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2017-12-31T20:30:34+00:00

Pull timer fixes from Thomas Gleixner: "A pile of fixes for long standing issues with the timer wheel and the NOHZ code: - Prevent timer base confusion accross the nohz switch, which can cause unlocked access and data corruption - Reinitialize the stale base clock on cpu hotplug to prevent subtle side effects including rollovers on 32bit - Prevent an interrupt storm when the timer softirq is already pending caused by tick_nohz_stop_sched_tick() - Move the timer start tracepoint to a place where it actually makes sense - Add documentation to timerqueue functions as they caused confusion several times now" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: timerqueue: Document return values of timerqueue_add/del() timers: Invoke timer_start_debug() where it makes sense nohz: Prevent a timer interrupt storm in tick_nohz_stop_sched_tick() timers: Reinitialize per cpu bases on hotplug timers: Use deferrable base independent of base::nohz_active

Merge tag 'driver-core-4.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

2017-12-31T18:50:05+00:00

Pull driver core fixes from Greg KH: "Here are two driver core fixes for 4.15-rc6, resolving some reported issues. The first is a cacheinfo fix for DT based systems to resolve a reported issue that has been around for a while, and the other is to resolve a regression in the kobject uevent code that showed up in 4.15-rc1. Both have been in linux-next for a while with no reported issues" * tag 'driver-core-4.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: kobject: fix suppressing modalias in uevents delivered over netlink drivers: base: cacheinfo: fix cache type for non-architected system cache