user/sven/linux.git/kernel, branch v4.4.166

namei: allow restricted O_CREAT of FIFOs and regular files

2018-12-01T08:46:41Z

commit 30aba6656f61ed44cba445a3c0d38b296fa9e8f5 upstream. Disallows open of FIFOs or regular files not owned by the user in world writable sticky directories, unless the owner is the same as that of the directory or the file is opened without the O_CREAT flag. The purpose is to make data spoofing attacks harder. This protection can be turned on and off separately for FIFOs and regular files via sysctl, just like the symlinks/hardlinks protection. This patch is based on Openwall's "HARDEN_FIFO" feature by Solar Designer. This is a brief list of old vulnerabilities that could have been prevented by this feature, some of them even allow for privilege escalation: CVE-2000-1134 CVE-2007-3852 CVE-2008-0525 CVE-2009-0416 CVE-2011-4834 CVE-2015-1838 CVE-2015-7442 CVE-2016-7489 This list is not meant to be complete. It's difficult to track down all vulnerabilities of this kind because they were often reported without any mention of this particular attack vector. In fact, before hardlinks/symlinks restrictions, fifos/regular files weren't the favorite vehicle to exploit them. [s.mesoraca16@gmail.com: fix bug reported by Dan Carpenter] Link: https://lkml.kernel.org/r/20180426081456.GA7060@mwanda Link: http://lkml.kernel.org/r/1524829819-11275-1-git-send-email-s.mesoraca16@gmail.com [keescook@chromium.org: drop pr_warn_ratelimited() in favor of audit changes in the future] [keescook@chromium.org: adjust commit subjet] Link: http://lkml.kernel.org/r/20180416175918.GA13494@beast Signed-off-by: Salvatore Mesoraca Signed-off-by: Kees Cook Suggested-by: Solar Designer Suggested-by: Kees Cook Cc: Al Viro Cc: Dan Carpenter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Cc: Loic Signed-off-by: Greg Kroah-Hartman

sched/core: Allow __sched_setscheduler() in interrupts when PI is not used

2018-12-01T08:46:41Z

commit 896bbb2522587e3b8eb2a0d204d43ccc1042a00d upstream. When priority inheritance was added back in 2.6.18 to sched_setscheduler(), it added a path to taking an rt-mutex wait_lock, which is not IRQ safe. As PI is not a common occurrence, lockdep will likely never trigger if sched_setscheduler was called from interrupt context. A BUG_ON() was added to trigger if __sched_setscheduler() was ever called from interrupt context because there was a possibility to take the wait_lock. Today the wait_lock is irq safe, but the path to taking it in sched_setscheduler() is the same as the path to taking it from normal context. The wait_lock is taken with raw_spin_lock_irq() and released with raw_spin_unlock_irq() which will indiscriminately enable interrupts, which would be bad in interrupt context. The problem is that normalize_rt_tasks, which is called by triggering the sysrq nice-all-RT-tasks was changed to call __sched_setscheduler(), and this is done from interrupt context! Now __sched_setscheduler() takes a "pi" parameter that is used to know if the priority inheritance should be called or not. As the BUG_ON() only cares about calling the PI code, it should only bug if called from interrupt context with the "pi" parameter set to true. Reported-by: Laurent Dufour Tested-by: Laurent Dufour Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Peter Zijlstra (Intel) Cc: Andrew Morton Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Fixes: dbc7f069b93a ("sched: Use replace normalize_task() with __sched_setscheduler()") Link: http://lkml.kernel.org/r/20170308124654.10e598f2@gandalf.local.home Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

kdb: Use strscpy with destination buffer size

2018-12-01T08:46:35Z

[ Upstream commit c2b94c72d93d0929f48157eef128c4f9d2e603ce ] gcc 8.1.0 warns with: kernel/debug/kdb/kdb_support.c: In function ‘kallsyms_symbol_next’: kernel/debug/kdb/kdb_support.c:239:4: warning: ‘strncpy’ specified bound depends on the length of the source argument [-Wstringop-overflow=] strncpy(prefix_name, name, strlen(name)+1); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ kernel/debug/kdb/kdb_support.c:239:31: note: length computed here Use strscpy() with the destination buffer size, and use ellipses when displaying truncated symbols. v2: Use strscpy() Signed-off-by: Prarit Bhargava Cc: Jonathan Toppins Cc: Jason Wessel Cc: Daniel Thompson Cc: kgdb-bugreport@lists.sourceforge.net Reviewed-by: Daniel Thompson Signed-off-by: Daniel Thompson Signed-off-by: Sasha Levin

genirq: Fix race on spurious interrupt detection

2018-11-21T08:27:35Z

commit 746a923b863a1065ef77324e1e43f19b1a3eab5c upstream. Commit 1e77d0a1ed74 ("genirq: Sanitize spurious interrupt detection of threaded irqs") made detection of spurious interrupts work for threaded handlers by: a) incrementing a counter every time the thread returns IRQ_HANDLED, and b) checking whether that counter has increased every time the thread is woken. However for oneshot interrupts, the commit unmasks the interrupt before incrementing the counter. If another interrupt occurs right after unmasking but before the counter is incremented, that interrupt is incorrectly considered spurious: time | irq_thread() | irq_thread_fn() | action->thread_fn() | irq_finalize_oneshot() | unmask_threaded_irq() /* interrupt is unmasked */ | | /* interrupt fires, incorrectly deemed spurious */ | | atomic_inc(&desc->threads_handled); /* counter is incremented */ v This is observed with a hi3110 CAN controller receiving data at high volume (from a separate machine sending with "cangen -g 0 -i -x"): The controller signals a huge number of interrupts (hundreds of millions per day) and every second there are about a dozen which are deemed spurious. In theory with high CPU load and the presence of higher priority tasks, the number of incorrectly detected spurious interrupts might increase beyond the 99,900 threshold and cause disablement of the interrupt. In practice it just increments the spurious interrupt count. But that can cause people to waste time investigating it over and over. Fix it by moving the accounting before the invocation of irq_finalize_oneshot(). [ tglx: Folded change log update ] Fixes: 1e77d0a1ed74 ("genirq: Sanitize spurious interrupt detection of threaded irqs") Signed-off-by: Lukas Wunner Signed-off-by: Thomas Gleixner Cc: Mathias Duckeck Cc: Akshay Bhat Cc: Casey Fitzpatrick Cc: stable@vger.kernel.org # v3.16+ Link: https://lkml.kernel.org/r/1dfd8bbd16163940648045495e3e9698e63b50ad.1539867047.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman

printk: Fix panic caused by passing log_buf_len to command line

2018-11-21T08:27:35Z

commit 277fcdb2cfee38ccdbe07e705dbd4896ba0c9930 upstream. log_buf_len_setup does not check input argument before passing it to simple_strtoull. The argument would be a NULL pointer if "log_buf_len", without its value, is set in command line and thus causes the following panic. PANIC: early exception 0xe3 IP 10:ffffffffaaeacd0d error 0 cr2 0x0 [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.19.0-rc4-yocto-standard+ #1 [ 0.000000] RIP: 0010:_parse_integer_fixup_radix+0xd/0x70 ... [ 0.000000] Call Trace: [ 0.000000] simple_strtoull+0x29/0x70 [ 0.000000] memparse+0x26/0x90 [ 0.000000] log_buf_len_setup+0x17/0x22 [ 0.000000] do_early_param+0x57/0x8e [ 0.000000] parse_args+0x208/0x320 [ 0.000000] ? rdinit_setup+0x30/0x30 [ 0.000000] parse_early_options+0x29/0x2d [ 0.000000] ? rdinit_setup+0x30/0x30 [ 0.000000] parse_early_param+0x36/0x4d [ 0.000000] setup_arch+0x336/0x99e [ 0.000000] start_kernel+0x6f/0x4ee [ 0.000000] x86_64_start_reservations+0x24/0x26 [ 0.000000] x86_64_start_kernel+0x6f/0x72 [ 0.000000] secondary_startup_64+0xa4/0xb0 This patch adds a check to prevent the panic. Link: http://lkml.kernel.org/r/1538239553-81805-1-git-send-email-zhe.he@windriver.com Cc: stable@vger.kernel.org Cc: rostedt@goodmis.org Cc: linux-kernel@vger.kernel.org Signed-off-by: He Zhe Reviewed-by: Sergey Senozhatsky Signed-off-by: Petr Mladek Signed-off-by: Greg Kroah-Hartman

kbuild: fix kernel/bounds.c 'W=1' warning

2018-11-21T08:27:35Z

commit 6a32c2469c3fbfee8f25bcd20af647326650a6cf upstream. Building any configuration with 'make W=1' produces a warning: kernel/bounds.c:16:6: warning: no previous prototype for 'foo' [-Wmissing-prototypes] When also passing -Werror, this prevents us from building any other files. Nobody ever calls the function, but we can't make it 'static' either since we want the compiler output. Calling it 'main' instead however avoids the warning, because gcc does not insist on having a declaration for main. Link: http://lkml.kernel.org/r/20181005083313.2088252-1-arnd@arndb.de Signed-off-by: Arnd Bergmann Reported-by: Kieran Bingham Reviewed-by: Kieran Bingham Cc: David Laight Cc: Masahiro Yamada Cc: Greg Kroah-Hartman Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

signal: Always deliver the kernel's SIGKILL and SIGSTOP to a pid namespace init

2018-11-21T08:27:33Z

[ Upstream commit 3597dfe01d12f570bc739da67f857fd222a3ea66 ] Instead of playing whack-a-mole and changing SEND_SIG_PRIV to SEND_SIG_FORCED throughout the kernel to ensure a pid namespace init gets signals sent by the kernel, stop allowing a pid namespace init to ignore SIGKILL or SIGSTOP sent by the kernel. A pid namespace init is only supposed to be able to ignore signals sent from itself and children with SIG_DFL. Fixes: 921cf9f63089 ("signals: protect cinit from unblocked SIG_DFL signals") Reviewed-by: Thomas Gleixner Signed-off-by: "Eric W. Biederman" Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

kprobes: Return error if we fail to reuse kprobe instead of BUG_ON()

2018-11-21T08:27:32Z

[ Upstream commit 819319fc93461c07b9cdb3064f154bd8cfd48172 ] Make reuse_unused_kprobe() to return error code if it fails to reuse unused kprobe for optprobe instead of calling BUG_ON(). Signed-off-by: Masami Hiramatsu Cc: Anil S Keshavamurthy Cc: David S . Miller Cc: Linus Torvalds Cc: Naveen N . Rao Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/153666124040.21306.14150398706331307654.stgit@devbox Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

locking/lockdep: Fix debug_locks off performance problem

2018-11-21T08:27:31Z

[ Upstream commit 9506a7425b094d2f1d9c877ed5a78f416669269b ] It was found that when debug_locks was turned off because of a problem found by the lockdep code, the system performance could drop quite significantly when the lock_stat code was also configured into the kernel. For instance, parallel kernel build time on a 4-socket x86-64 server nearly doubled. Further analysis into the cause of the slowdown traced back to the frequent call to debug_locks_off() from the __lock_acquired() function probably due to some inconsistent lockdep states with debug_locks off. The debug_locks_off() function did an unconditional atomic xchg to write a 0 value into debug_locks which had already been set to 0. This led to severe cacheline contention in the cacheline that held debug_locks. As debug_locks is being referenced in quite a few different places in the kernel, this greatly slow down the system performance. To prevent that trashing of debug_locks cacheline, lock_acquired() and lock_contended() now checks the state of debug_locks before proceeding. The debug_locks_off() function is also modified to check debug_locks before calling __debug_locks_off(). Signed-off-by: Waiman Long Cc: Andrew Morton Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Will Deacon Link: http://lkml.kernel.org/r/1539913518-15598-1-git-send-email-longman@redhat.com Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

cpuidle: Do not access cpuidle_devices when !CONFIG_CPU_IDLE

2018-11-10T15:41:43Z

commit 9bd616e3dbedfc103f158197c8ad93678849b1ed upstream. The cpuidle_devices per-CPU variable is only defined when CPU_IDLE is enabled. Commit c8cc7d4de7a4 ("sched/idle: Reorganize the idle loop") removed the #ifdef CONFIG_CPU_IDLE around cpuidle_idle_call() with the compiler optimising away __this_cpu_read(cpuidle_devices). However, with CONFIG_UBSAN && !CONFIG_CPU_IDLE, this optimisation no longer happens and the kernel fails to link since cpuidle_devices is not defined. This patch introduces an accessor function for the current CPU cpuidle device (returning NULL when !CONFIG_CPU_IDLE) and uses it in cpuidle_idle_call(). Signed-off-by: Catalin Marinas Cc: 4.5+ # 4.5+ Signed-off-by: Rafael J. Wysocki Cc: Guenter Roeck Signed-off-by: Greg Kroah-Hartman