user/sven/linux.git/include, branch v5.0.16

cpu/speculation: Add 'mitigations=' cmdline option

2019-05-14T17:17:13Z

commit 98af8452945c55652de68536afdde3b520fec429 upstream Keeping track of the number of mitigations for all the CPU speculation bugs has become overwhelming for many users. It's getting more and more complicated to decide which mitigations are needed for a given architecture. Complicating matters is the fact that each arch tends to have its own custom way to mitigate the same vulnerability. Most users fall into a few basic categories: a) they want all mitigations off; b) they want all reasonable mitigations on, with SMT enabled even if it's vulnerable; or c) they want all reasonable mitigations on, with SMT disabled if vulnerable. Define a set of curated, arch-independent options, each of which is an aggregation of existing options: - mitigations=off: Disable all mitigations. - mitigations=auto: [default] Enable all the default mitigations, but leave SMT enabled, even if it's vulnerable. - mitigations=auto,nosmt: Enable all the default mitigations, disabling SMT if needed by a mitigation. Currently, these options are placeholders which don't actually do anything. They will be fleshed out in upcoming patches. Signed-off-by: Josh Poimboeuf Signed-off-by: Thomas Gleixner Tested-by: Jiri Kosina (on x86) Reviewed-by: Jiri Kosina Cc: Borislav Petkov Cc: "H . Peter Anvin" Cc: Andy Lutomirski Cc: Peter Zijlstra Cc: Jiri Kosina Cc: Waiman Long Cc: Andrea Arcangeli Cc: Jon Masters Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Cc: linuxppc-dev@lists.ozlabs.org Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: linux-s390@vger.kernel.org Cc: Catalin Marinas Cc: Will Deacon Cc: linux-arm-kernel@lists.infradead.org Cc: linux-arch@vger.kernel.org Cc: Greg Kroah-Hartman Cc: Tyler Hicks Cc: Linus Torvalds Cc: Randy Dunlap Cc: Steven Price Cc: Phil Auld Link: https://lkml.kernel.org/r/b07a8ef9b7c5055c3a4637c87d07c296d5016fe0.1555085500.git.jpoimboe@redhat.com Signed-off-by: Greg Kroah-Hartman

x86/speculation/mds: Add sysfs reporting for MDS

2019-05-14T17:17:11Z

commit 8a4b06d391b0a42a373808979b5028f5c84d9c6a upstream Add the sysfs reporting file for MDS. It exposes the vulnerability and mitigation state similar to the existing files for the other speculative hardware vulnerabilities. Signed-off-by: Thomas Gleixner Reviewed-by: Greg Kroah-Hartman Reviewed-by: Borislav Petkov Reviewed-by: Jon Masters Tested-by: Jon Masters Signed-off-by: Greg Kroah-Hartman

Bluetooth: Align minimum encryption key size for LE and BR/EDR connections

2019-05-10T16:36:13Z

commit d5bb334a8e171b262e48f378bd2096c0ea458265 upstream. The minimum encryption key size for LE connections is 56 bits and to align LE with BR/EDR, enforce 56 bits of minimum encryption key size for BR/EDR connections as well. Signed-off-by: Marcel Holtmann Signed-off-by: Johan Hedberg Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

nvmet: fix discover log page when offsets are used

2019-05-10T16:36:11Z

[ Upstream commit d808b7f759b50acf0784ce6230ffa63e12ef465d ] The nvme target hadn't been taking the Get Log Page offset parameter into consideration, and so has been returning corrupted log pages when offsets are used. Since many tools, including nvme-cli, split the log request to 4k, we've been breaking discovery log responses when more than 3 subsystems exist. Fix the returned data by internally generating the entire discovery log page and copying only the requested bytes into the user buffer. The command log page offset type has been modified to a native __le64 to make it easier to extract the value from a command. Signed-off-by: Keith Busch Tested-by: Minwoo Im Reviewed-by: Chaitanya Kulkarni Reviewed-by: Hannes Reinecke Reviewed-by: James Smart Signed-off-by: Christoph Hellwig Signed-off-by: Sasha Levin

blk-mq: introduce blk_mq_complete_request_sync()

2019-05-10T16:36:11Z

[ Upstream commit 1b8f21b74c3c9c82fce5a751d7aefb7cc0b8d33d ] In NVMe's error handler, follows the typical steps of tearing down hardware for recovering controller: 1) stop blk_mq hw queues 2) stop the real hw queues 3) cancel in-flight requests via blk_mq_tagset_busy_iter(tags, cancel_request, ...) cancel_request(): mark the request as abort blk_mq_complete_request(req); 4) destroy real hw queues However, there may be race between #3 and #4, because blk_mq_complete_request() may run q->mq_ops->complete(rq) remotelly and asynchronously, and ->complete(rq) may be run after #4. This patch introduces blk_mq_complete_request_sync() for fixing the above race. Cc: Sagi Grimberg Cc: Bart Van Assche Cc: James Smart Cc: linux-nvme@lists.infradead.org Reviewed-by: Keith Busch Reviewed-by: Christoph Hellwig Signed-off-by: Ming Lei Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

KEYS: trusted: fix -Wvarags warning

2019-05-10T16:36:10Z

[ Upstream commit be24b37e22c20cbaa891971616784dd0f35211e8 ] Fixes the warning reported by Clang: security/keys/trusted.c:146:17: warning: passing an object that undergoes default argument promotion to 'va_start' has undefined behavior [-Wvarargs] va_start(argp, h3); ^ security/keys/trusted.c:126:37: note: parameter of type 'unsigned char' is declared here unsigned char *h2, unsigned char h3, ...) ^ Specifically, it seems that both the C90 (4.8.1.1) and C11 (7.16.1.4) standards explicitly call this out as undefined behavior: The parameter parmN is the identifier of the rightmost parameter in the variable parameter list in the function definition (the one just before the ...). If the parameter parmN is declared with ... or with a type that is not compatible with the type that results after application of the default argument promotions, the behavior is undefined. Link: https://github.com/ClangBuiltLinux/linux/issues/41 Link: https://www.eskimo.com/~scs/cclass/int/sx11c.html Suggested-by: David Laight Suggested-by: Denis Kenzior Suggested-by: James Bottomley Suggested-by: Nathan Chancellor Signed-off-by: Nick Desaulniers Reviewed-by: Nathan Chancellor Tested-by: Nathan Chancellor Reviewed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen Signed-off-by: James Morris Signed-off-by: Sasha Levin

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

2019-05-10T16:36:08Z

[ 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

ASoC: dpcm: prevent snd_soc_dpcm use after free

2019-05-10T16:36:05Z

[ Upstream commit a9764869779081e8bf24da07ac040e8f3efcf13a ] The dpcm get from fe_clients/be_clients may be free before use Add a spin lock at snd_soc_card level, to protect the dpcm instance. The lock may be used in atomic context, so use spin lock. Use irq spin lock version, since the lock may be used in interrupts. possible race condition between void dpcm_be_disconnect( ... list_del(&dpcm->list_be); list_del(&dpcm->list_fe); kfree(dpcm); ... and for_each_dpcm_fe() for_each_dpcm_be*() race condition example Thread 1: snd_soc_dapm_mixer_update_power() -> soc_dpcm_runtime_update() -> dpcm_be_disconnect() -> kfree(dpcm); Thread 2: dpcm_fe_dai_trigger() -> dpcm_be_dai_trigger() -> snd_soc_dpcm_can_be_free_stop() -> if (dpcm->fe == fe) Excpetion Scenario: two FE link to same BE FE1 -> BE FE2 -> Thread 1: switch of mixer between FE2 -> BE Thread 2: pcm_stop FE1 Exception: Unable to handle kernel paging request at virtual address dead0000000000e0 pc=<> [] dpcm_be_dai_trigger+0x29c/0x47c sound/soc/soc-pcm.c:3226 if (dpcm->fe == fe) lr=<> [] dpcm_fe_dai_do_trigger+0x94/0x26c Backtrace: [] notify_die+0x68/0xb8 [] die+0x118/0x2a8 [] __do_kernel_fault+0x13c/0x14c [] do_translation_fault+0x64/0xa0 [] do_mem_abort+0x4c/0xd0 [] el1_da+0x24/0x40 [] dpcm_be_dai_trigger+0x29c/0x47c [] dpcm_fe_dai_do_trigger+0x94/0x26c [] dpcm_fe_dai_trigger+0x3c/0x44 [] snd_pcm_do_stop+0x50/0x5c [] snd_pcm_action+0xb4/0x13c [] snd_pcm_drop+0xa0/0x128 [] snd_pcm_common_ioctl+0x9d8/0x30f0 [] snd_pcm_ioctl_compat+0x29c/0x2f14 [] compat_SyS_ioctl+0x128/0x244 [] el0_svc_naked+0x34/0x38 [] 0xffffffffffffffff Signed-off-by: KaiChieh Chuang Signed-off-by: Mark Brown Signed-off-by: Sasha Levin

clk: x86: Add system specific quirk to mark clocks as critical

2019-05-08T05:22:59Z

commit 7c2e07130090ae001a97a6b65597830d6815e93e upstream. Since commit 648e921888ad ("clk: x86: Stop marking clocks as CLK_IS_CRITICAL"), the pmc_plt_clocks of the Bay Trail SoC are unconditionally gated off. Unfortunately this will break systems where these clocks are used for external purposes beyond the kernel's knowledge. Fix it by implementing a system specific quirk to mark the necessary pmc_plt_clks as critical. Fixes: 648e921888ad ("clk: x86: Stop marking clocks as CLK_IS_CRITICAL") Signed-off-by: David Müller Signed-off-by: Hans de Goede Reviewed-by: Andy Shevchenko Signed-off-by: Stephen Boyd Signed-off-by: Greg Kroah-Hartman

fs: stream_open - opener for stream-like files so that read and write can run simultaneously without deadlock

2019-05-08T05:22:55Z

[ Upstream commit 10dce8af34226d90fa56746a934f8da5dcdba3df ] Commit 9c225f2655e3 ("vfs: atomic f_pos accesses as per POSIX") added locking for file.f_pos access and in particular made concurrent read and write not possible - now both those functions take f_pos lock for the whole run, and so if e.g. a read is blocked waiting for data, write will deadlock waiting for that read to complete. This caused regression for stream-like files where previously read and write could run simultaneously, but after that patch could not do so anymore. See e.g. commit 581d21a2d02a ("xenbus: fix deadlock on writes to /proc/xen/xenbus") which fixes such regression for particular case of /proc/xen/xenbus. The patch that added f_pos lock in 2014 did so to guarantee POSIX thread safety for read/write/lseek and added the locking to file descriptors of all regular files. In 2014 that thread-safety problem was not new as it was already discussed earlier in 2006. However even though 2006'th version of Linus's patch was adding f_pos locking "only for files that are marked seekable with FMODE_LSEEK (thus avoiding the stream-like objects like pipes and sockets)", the 2014 version - the one that actually made it into the tree as 9c225f2655e3 - is doing so irregardless of whether a file is seekable or not. See https://lore.kernel.org/lkml/53022DB1.4070805@gmail.com/ https://lwn.net/Articles/180387 https://lwn.net/Articles/180396 for historic context. The reason that it did so is, probably, that there are many files that are marked non-seekable, but e.g. their read implementation actually depends on knowing current position to correctly handle the read. Some examples: kernel/power/user.c snapshot_read fs/debugfs/file.c u32_array_read fs/fuse/control.c fuse_conn_waiting_read + ... drivers/hwmon/asus_atk0110.c atk_debugfs_ggrp_read arch/s390/hypfs/inode.c hypfs_read_iter ... Despite that, many nonseekable_open users implement read and write with pure stream semantics - they don't depend on passed ppos at all. And for those cases where read could wait for something inside, it creates a situation similar to xenbus - the write could be never made to go until read is done, and read is waiting for some, potentially external, event, for potentially unbounded time -> deadlock. Besides xenbus, there are 14 such places in the kernel that I've found with semantic patch (see below): drivers/xen/evtchn.c:667:8-24: ERROR: evtchn_fops: .read() can deadlock .write() drivers/isdn/capi/capi.c:963:8-24: ERROR: capi_fops: .read() can deadlock .write() drivers/input/evdev.c:527:1-17: ERROR: evdev_fops: .read() can deadlock .write() drivers/char/pcmcia/cm4000_cs.c:1685:7-23: ERROR: cm4000_fops: .read() can deadlock .write() net/rfkill/core.c:1146:8-24: ERROR: rfkill_fops: .read() can deadlock .write() drivers/s390/char/fs3270.c:488:1-17: ERROR: fs3270_fops: .read() can deadlock .write() drivers/usb/misc/ldusb.c:310:1-17: ERROR: ld_usb_fops: .read() can deadlock .write() drivers/hid/uhid.c:635:1-17: ERROR: uhid_fops: .read() can deadlock .write() net/batman-adv/icmp_socket.c:80:1-17: ERROR: batadv_fops: .read() can deadlock .write() drivers/media/rc/lirc_dev.c:198:1-17: ERROR: lirc_fops: .read() can deadlock .write() drivers/leds/uleds.c:77:1-17: ERROR: uleds_fops: .read() can deadlock .write() drivers/input/misc/uinput.c:400:1-17: ERROR: uinput_fops: .read() can deadlock .write() drivers/infiniband/core/user_mad.c:985:7-23: ERROR: umad_fops: .read() can deadlock .write() drivers/gnss/core.c:45:1-17: ERROR: gnss_fops: .read() can deadlock .write() In addition to the cases above another regression caused by f_pos locking is that now FUSE filesystems that implement open with FOPEN_NONSEEKABLE flag, can no longer implement bidirectional stream-like files - for the same reason as above e.g. read can deadlock write locking on file.f_pos in the kernel. FUSE's FOPEN_NONSEEKABLE was added in 2008 in a7c1b990f715 ("fuse: implement nonseekable open") to support OSSPD. OSSPD implements /dev/dsp in userspace with FOPEN_NONSEEKABLE flag, with corresponding read and write routines not depending on current position at all, and with both read and write being potentially blocking operations: See https://github.com/libfuse/osspd https://lwn.net/Articles/308445 https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1406 https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1438-L1477 https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1479-L1510 Corresponding libfuse example/test also describes FOPEN_NONSEEKABLE as "somewhat pipe-like files ..." with read handler not using offset. However that test implements only read without write and cannot exercise the deadlock scenario: https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L124-L131 https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L146-L163 https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L209-L216 I've actually hit the read vs write deadlock for real while implementing my FUSE filesystem where there is /head/watch file, for which open creates separate bidirectional socket-like stream in between filesystem and its user with both read and write being later performed simultaneously. And there it is semantically not easy to split the stream into two separate read-only and write-only channels: https://lab.nexedi.com/kirr/wendelin.core/blob/f13aa600/wcfs/wcfs.go#L88-169 Let's fix this regression. The plan is: 1. We can't change nonseekable_open to include &~FMODE_ATOMIC_POS - doing so would break many in-kernel nonseekable_open users which actually use ppos in read/write handlers. 2. Add stream_open() to kernel to open stream-like non-seekable file descriptors. Read and write on such file descriptors would never use nor change ppos. And with that property on stream-like files read and write will be running without taking f_pos lock - i.e. read and write could be running simultaneously. 3. With semantic patch search and convert to stream_open all in-kernel nonseekable_open users for which read and write actually do not depend on ppos and where there is no other methods in file_operations which assume @offset access. 4. Add FOPEN_STREAM to fs/fuse/ and open in-kernel file-descriptors via steam_open if that bit is present in filesystem open reply. It was tempting to change fs/fuse/ open handler to use stream_open instead of nonseekable_open on just FOPEN_NONSEEKABLE flags, but grepping through Debian codesearch shows users of FOPEN_NONSEEKABLE, and in particular GVFS which actually uses offset in its read and write handlers https://codesearch.debian.net/search?q=-%3Enonseekable+%3D https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1080 https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1247-1346 https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1399-1481 so if we would do such a change it will break a real user. 5. Add stream_open and FOPEN_STREAM handling to stable kernels starting from v3.14+ (the kernel where 9c225f2655 first appeared). This will allow to patch OSSPD and other FUSE filesystems that provide stream-like files to return FOPEN_STREAM | FOPEN_NONSEEKABLE in their open handler and this way avoid the deadlock on all kernel versions. This should work because fs/fuse/ ignores unknown open flags returned from a filesystem and so passing FOPEN_STREAM to a kernel that is not aware of this flag cannot hurt. In turn the kernel that is not aware of FOPEN_STREAM will be < v3.14 where just FOPEN_NONSEEKABLE is sufficient to implement streams without read vs write deadlock. This patch adds stream_open, converts /proc/xen/xenbus to it and adds semantic patch to automatically locate in-kernel places that are either required to be converted due to read vs write deadlock, or that are just safe to be converted because read and write do not use ppos and there are no other funky methods in file_operations. Regarding semantic patch I've verified each generated change manually - that it is correct to convert - and each other nonseekable_open instance left - that it is either not correct to convert there, or that it is not converted due to current stream_open.cocci limitations. The script also does not convert files that should be valid to convert, but that currently have .llseek = noop_llseek or generic_file_llseek for unknown reason despite file being opened with nonseekable_open (e.g. drivers/input/mousedev.c) Cc: Michael Kerrisk Cc: Yongzhi Pan Cc: Jonathan Corbet Cc: David Vrabel Cc: Juergen Gross Cc: Miklos Szeredi Cc: Tejun Heo Cc: Kirill Tkhai Cc: Arnd Bergmann Cc: Christoph Hellwig Cc: Greg Kroah-Hartman Cc: Julia Lawall Cc: Nikolaus Rath Cc: Han-Wen Nienhuys Signed-off-by: Kirill Smelkov Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin (Microsoft)