user/sven/linux.git/include/linux/sched.h, branch v3.18.104

pids: make task_tgid_nr_ns() safe

2017-08-25T00:00:10Z

commit dd1c1f2f2028a7b851f701fc6a8ebe39dcb95e7c upstream. This was reported many times, and this was even mentioned in commit 52ee2dfdd4f5 ("pids: refactor vnr/nr_ns helpers to make them safe") but somehow nobody bothered to fix the obvious problem: task_tgid_nr_ns() is not safe because task->group_leader points to nowhere after the exiting task passes exit_notify(), rcu_read_lock() can not help. We really need to change __unhash_process() to nullify group_leader, parent, and real_parent, but this needs some cleanups. Until then we can turn task_tgid_nr_ns() into another user of __task_pid_nr_ns() and fix the problem. Reported-by: Troy Kensinger Signed-off-by: Oleg Nesterov Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

signal: protect SIGNAL_UNKILLABLE from unintentional clearing.

2017-08-11T16:30:16Z

[ Upstream commit 2d39b3cd34e6d323720d4c61bd714f5ae202c022 ] Since commit 00cd5c37afd5 ("ptrace: permit ptracing of /sbin/init") we can now trace init processes. init is initially protected with SIGNAL_UNKILLABLE which will prevent fatal signals such as SIGSTOP, but there are a number of paths during tracing where SIGNAL_UNKILLABLE can be implicitly cleared. This can result in init becoming stoppable/killable after tracing. For example, running: while true; do kill -STOP 1; done & strace -p 1 and then stopping strace and the kill loop will result in init being left in state TASK_STOPPED. Sending SIGCONT to init will resume it, but init will now respond to future SIGSTOP signals rather than ignoring them. Make sure that when setting SIGNAL_STOP_CONTINUED/SIGNAL_STOP_STOPPED that we don't clear SIGNAL_UNKILLABLE. Link: http://lkml.kernel.org/r/20170104122017.25047-1-jamie.iles@oracle.com Signed-off-by: Jamie Iles Acked-by: Oleg Nesterov Cc: Alexander Viro Cc: Ingo Molnar Cc: Peter Zijlstra Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

pipe: limit the per-user amount of pages allocated in pipes

2016-07-12T12:48:19Z

[ Upstream commit 759c01142a5d0f364a462346168a56de28a80f52 ] On no-so-small systems, it is possible for a single process to cause an OOM condition by filling large pipes with data that are never read. A typical process filling 4000 pipes with 1 MB of data will use 4 GB of memory. On small systems it may be tricky to set the pipe max size to prevent this from happening. This patch makes it possible to enforce a per-user soft limit above which new pipes will be limited to a single page, effectively limiting them to 4 kB each, as well as a hard limit above which no new pipes may be created for this user. This has the effect of protecting the system against memory abuse without hurting other users, and still allowing pipes to work correctly though with less data at once. The limit are controlled by two new sysctls : pipe-user-pages-soft, and pipe-user-pages-hard. Both may be disabled by setting them to zero. The default soft limit allows the default number of FDs per process (1024) to create pipes of the default size (64kB), thus reaching a limit of 64MB before starting to create only smaller pipes. With 256 processes limited to 1024 FDs each, this results in 1024*64kB + (256*1024 - 1024) * 4kB = 1084 MB of memory allocated for a user. The hard limit is disabled by default to avoid breaking existing applications that make intensive use of pipes (eg: for splicing). Reported-by: socketpair@gmail.com Reported-by: Tetsuo Handa Mitigates: CVE-2013-4312 (Linux 2.0+) Suggested-by: Linus Torvalds Signed-off-by: Willy Tarreau Signed-off-by: Al Viro Signed-off-by: Sasha Levin

unix: properly account for FDs passed over unix sockets

2016-02-15T20:42:43Z

[ Upstream commit 712f4aad406bb1ed67f3f98d04c044191f0ff593 ] It is possible for a process to allocate and accumulate far more FDs than the process' limit by sending them over a unix socket then closing them to keep the process' fd count low. This change addresses this problem by keeping track of the number of FDs in flight per user and preventing non-privileged processes from having more FDs in flight than their configured FD limit. Reported-by: socketpair@gmail.com Reported-by: Tetsuo Handa Mitigates: CVE-2013-4312 (Linux 2.0+) Suggested-by: Linus Torvalds Acked-by: Hannes Frederic Sowa Signed-off-by: Willy Tarreau Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

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

2014-10-13T14:23:15Z

Pull scheduler updates from Ingo Molnar: "The main changes in this cycle were: - Optimized support for Intel "Cluster-on-Die" (CoD) topologies (Dave Hansen) - Various sched/idle refinements for better idle handling (Nicolas Pitre, Daniel Lezcano, Chuansheng Liu, Vincent Guittot) - sched/numa updates and optimizations (Rik van Riel) - sysbench speedup (Vincent Guittot) - capacity calculation cleanups/refactoring (Vincent Guittot) - Various cleanups to thread group iteration (Oleg Nesterov) - Double-rq-lock removal optimization and various refactorings (Kirill Tkhai) - various sched/deadline fixes ... and lots of other changes" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (72 commits) sched/dl: Use dl_bw_of() under rcu_read_lock_sched() sched/fair: Delete resched_cpu() from idle_balance() sched, time: Fix build error with 64 bit cputime_t on 32 bit systems sched: Improve sysbench performance by fixing spurious active migration sched/x86: Fix up typo in topology detection x86, sched: Add new topology for multi-NUMA-node CPUs sched/rt: Use resched_curr() in task_tick_rt() sched: Use rq->rd in sched_setaffinity() under RCU read lock sched: cleanup: Rename 'out_unlock' to 'out_free_new_mask' sched: Use dl_bw_of() under RCU read lock sched/fair: Remove duplicate code from can_migrate_task() sched, mips, ia64: Remove __ARCH_WANT_UNLOCKED_CTXSW sched: print_rq(): Don't use tasklist_lock sched: normalize_rt_tasks(): Don't use _irqsave for tasklist_lock, use task_rq_lock() sched: Fix the task-group check in tg_has_rt_tasks() sched/fair: Leverage the idle state info when choosing the "idlest" cpu sched: Let the scheduler see CPU idle states sched/deadline: Fix inter- exclusive cpusets migrations sched/deadline: Clear dl_entity params when setscheduling to different class sched/numa: Kill the wrong/dead TASK_DEAD check in task_numa_fault() ...

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

2014-10-13T13:44:12Z

Pull RCU updates from Ingo Molnar: "The main changes in this cycle were: - changes related to No-CBs CPUs and NO_HZ_FULL - RCU-tasks implementation - torture-test updates - miscellaneous fixes - locktorture updates - RCU documentation updates" * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (81 commits) workqueue: Use cond_resched_rcu_qs macro workqueue: Add quiescent state between work items locktorture: Cleanup header usage locktorture: Cannot hold read and write lock locktorture: Fix __acquire annotation for spinlock irq locktorture: Support rwlocks rcu: Eliminate deadlock between CPU hotplug and expedited grace periods locktorture: Document boot/module parameters rcutorture: Rename rcutorture_runnable parameter locktorture: Add test scenario for rwsem_lock locktorture: Add test scenario for mutex_lock locktorture: Make torture scripting account for new _runnable name locktorture: Introduce torture context locktorture: Support rwsems locktorture: Add infrastructure for torturing read locks torture: Address race in module cleanup locktorture: Make statistics generic locktorture: Teach about lock debugging locktorture: Support mutexes locktorture: Add documentation ...

mm: clear __GFP_FS when PF_MEMALLOC_NOIO is set

2014-10-10T02:25:58Z

commit 21caf2fc1931 ("mm: teach mm by current context info to not do I/O during memory allocation") introduces PF_MEMALLOC_NOIO flag to avoid doing I/O inside memory allocation, __GFP_IO is cleared when this flag is set, but __GFP_FS implies __GFP_IO, it should also be cleared. Or it may still run into I/O, like in superblock shrinker. And this will make the kernel run into the deadlock case described in that commit. See Dave Chinner's comment about io in superblock shrinker: Filesystem shrinkers do indeed perform IO from the superblock shrinker and have for years. Even clean inodes can require IO before they can be freed - e.g. on an orphan list, need truncation of post-eof blocks, need to wait for ordered operations to complete before it can be freed, etc. IOWs, Ext4, btrfs and XFS all can issue and/or block on arbitrary amounts of IO in the superblock shrinker context. XFS, in particular, has been doing transactions and IO from the VFS inode cache shrinker since it was first introduced.... Fix this by clearing __GFP_FS in memalloc_noio_flags(), this function has masked all the gfp_mask that will be passed into fs for the processes setting PF_MEMALLOC_NOIO in the direct reclaim path. v1 thread at: https://lkml.org/lkml/2014/9/3/32 Signed-off-by: Junxiao Bi Cc: Dave Chinner Cc: joyce.xue Cc: Ming Lei Cc: Trond Myklebust Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6

2014-10-08T10:44:48Z

Pull crypto update from Herbert Xu: - add multibuffer infrastructure (single_task_running scheduler helper, OKed by Peter on lkml. - add SHA1 multibuffer implementation for AVX2. - reenable "by8" AVX CTR optimisation after fixing counter overflow. - add APM X-Gene SoC RNG support. - SHA256/SHA512 now handles unaligned input correctly. - set lz4 decompressed length correctly. - fix algif socket buffer allocation failure for 64K page machines. - misc fixes * git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (47 commits) crypto: sha - Handle unaligned input data in generic sha256 and sha512. Revert "crypto: aesni - disable "by8" AVX CTR optimization" crypto: aesni - remove unused defines in "by8" variant crypto: aesni - fix counter overflow handling in "by8" variant hwrng: printk replacement crypto: qat - Removed unneeded partial state crypto: qat - Fix typo in name of tasklet_struct crypto: caam - Dynamic allocation of addresses for various memory blocks in CAAM. crypto: mcryptd - Fix typos in CRYPTO_MCRYPTD description crypto: algif - avoid excessive use of socket buffer in skcipher arm64: dts: add random number generator dts node to APM X-Gene platform. Documentation: rng: Add X-Gene SoC RNG driver documentation hwrng: xgene - add support for APM X-Gene SoC RNG support crypto: mv_cesa - Add missing #define crypto: testmgr - add test for lz4 and lz4hc crypto: lz4,lz4hc - fix decompression crypto: qat - Use pci_enable_msix_exact() instead of pci_enable_msix() crypto: drbg - fix maximum value checks on 32 bit systems crypto: drbg - fix sparse warning for cpu_to_be[32|64] crypto: sha-mb - sha1_mb_alg_state can be static ...

Merge branch 'for-3.17-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

2014-09-27T23:45:33Z

Pull cgroup fixes from Tejun Heo: "This is quite late but these need to be backported anyway. This is the fix for a long-standing cpuset bug which existed from 2009. cpuset makes use of PF_SPREAD_{PAGE|SLAB} flags to modify the task's memory allocation behavior according to the settings of the cpuset it belongs to; unfortunately, when those flags have to be changed, cpuset did so directly even whlie the target task is running, which is obviously racy as task->flags may be modified by the task itself at any time. This obscure bug manifested as corrupt PF_USED_MATH flag leading to a weird crash. The bug is fixed by moving the flag to task->atomic_flags. The first two are prepatory ones to help defining atomic_flags accessors and the third one is the actual fix" * 'for-3.17-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cpuset: PF_SPREAD_PAGE and PF_SPREAD_SLAB should be atomic flags sched: add macros to define bitops for task atomic flags sched: fix confusing PFA_NO_NEW_PRIVS constant

cpuset: PF_SPREAD_PAGE and PF_SPREAD_SLAB should be atomic flags

2014-09-25T02:16:06Z

When we change cpuset.memory_spread_{page,slab}, cpuset will flip PF_SPREAD_{PAGE,SLAB} bit of tsk->flags for each task in that cpuset. This should be done using atomic bitops, but currently we don't, which is broken. Tetsuo reported a hard-to-reproduce kernel crash on RHEL6, which happened when one thread tried to clear PF_USED_MATH while at the same time another thread tried to flip PF_SPREAD_PAGE/PF_SPREAD_SLAB. They both operate on the same task. Here's the full report: https://lkml.org/lkml/2014/9/19/230 To fix this, we make PF_SPREAD_PAGE and PF_SPREAD_SLAB atomic flags. v4: - updated mm/slab.c. (Fengguang Wu) - updated Documentation. Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Miao Xie Cc: Kees Cook Fixes: 950592f7b991 ("cpusets: update tasks' page/slab spread flags in time") Cc: # 2.6.31+ Reported-by: Tetsuo Handa Signed-off-by: Zefan Li Signed-off-by: Tejun Heo