user/sven/linux.git/kernel, branch v4.14.141

genirq: Properly pair kobject_del() with kobject_add()

2019-08-29T06:26:44Z

commit d0ff14fdc987303aeeb7de6f1bd72c3749ae2a9b upstream. If alloc_descs() fails before irq_sysfs_init() has run, free_desc() in the cleanup path will call kobject_del() even though the kobject has not been added with kobject_add(). Fix this by making the call to kobject_del() conditional on whether irq_sysfs_init() has run. This problem surfaced because commit aa30f47cf666 ("kobject: Add support for default attribute groups to kobj_type") makes kobject_del() stricter about pairing with kobject_add(). If the pairing is incorrrect, a WARNING and backtrace occur in sysfs_remove_group() because there is no parent. [ tglx: Add a comment to the code and make it work with CONFIG_SYSFS=n ] Fixes: ecb3f394c5db ("genirq: Expose interrupt information through sysfs") Signed-off-by: Michael Kelley Signed-off-by: Thomas Gleixner Acked-by: Greg Kroah-Hartman Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/1564703564-4116-1-git-send-email-mikelley@microsoft.com Signed-off-by: Greg Kroah-Hartman

bpf: fix bpf_jit_limit knob for PAGE_SIZE >= 64K

2019-08-25T08:50:23Z

[ Upstream commit fdadd04931c2d7cd294dc5b2b342863f94be53a3 ] Michael and Sandipan report: Commit ede95a63b5 introduced a bpf_jit_limit tuneable to limit BPF JIT allocations. At compile time it defaults to PAGE_SIZE * 40000, and is adjusted again at init time if MODULES_VADDR is defined. For ppc64 kernels, MODULES_VADDR isn't defined, so we're stuck with the compile-time default at boot-time, which is 0x9c400000 when using 64K page size. This overflows the signed 32-bit bpf_jit_limit value: root@ubuntu:/tmp# cat /proc/sys/net/core/bpf_jit_limit -1673527296 and can cause various unexpected failures throughout the network stack. In one case `strace dhclient eth0` reported: setsockopt(5, SOL_SOCKET, SO_ATTACH_FILTER, {len=11, filter=0x105dd27f8}, 16) = -1 ENOTSUPP (Unknown error 524) and similar failures can be seen with tools like tcpdump. This doesn't always reproduce however, and I'm not sure why. The more consistent failure I've seen is an Ubuntu 18.04 KVM guest booted on a POWER9 host would time out on systemd/netplan configuring a virtio-net NIC with no noticeable errors in the logs. Given this and also given that in near future some architectures like arm64 will have a custom area for BPF JIT image allocations we should get rid of the BPF_JIT_LIMIT_DEFAULT fallback / default entirely. For 4.21, we have an overridable bpf_jit_alloc_exec(), bpf_jit_free_exec() so therefore add another overridable bpf_jit_alloc_exec_limit() helper function which returns the possible size of the memory area for deriving the default heuristic in bpf_jit_charge_init(). Like bpf_jit_alloc_exec() and bpf_jit_free_exec(), the new bpf_jit_alloc_exec_limit() assumes that module_alloc() is the default JIT memory provider, and therefore in case archs implement their custom module_alloc() we use MODULES_{END,_VADDR} for limits and otherwise for vmalloc_exec() cases like on ppc64 we use VMALLOC_{END,_START}. Additionally, for archs supporting large page sizes, we should change the sysctl to be handled as long to not run into sysctl restrictions in future. Fixes: ede95a63b5e8 ("bpf: add bpf_jit_limit knob to restrict unpriv allocations") Reported-by: Sandipan Das Reported-by: Michael Roth Signed-off-by: Daniel Borkmann Tested-by: Michael Roth Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

bpf: add bpf_jit_limit knob to restrict unpriv allocations

2019-08-25T08:50:03Z

commit ede95a63b5e84ddeea6b0c473b36ab8bfd8c6ce3 upstream. Rick reported that the BPF JIT could potentially fill the entire module space with BPF programs from unprivileged users which would prevent later attempts to load normal kernel modules or privileged BPF programs, for example. If JIT was enabled but unsuccessful to generate the image, then before commit 290af86629b2 ("bpf: introduce BPF_JIT_ALWAYS_ON config") we would always fall back to the BPF interpreter. Nowadays in the case where the CONFIG_BPF_JIT_ALWAYS_ON could be set, then the load will abort with a failure since the BPF interpreter was compiled out. Add a global limit and enforce it for unprivileged users such that in case of BPF interpreter compiled out we fail once the limit has been reached or we fall back to BPF interpreter earlier w/o using module mem if latter was compiled in. In a next step, fair share among unprivileged users can be resolved in particular for the case where we would fail hard once limit is reached. Fixes: 290af86629b2 ("bpf: introduce BPF_JIT_ALWAYS_ON config") Fixes: 0a14842f5a3c ("net: filter: Just In Time compiler for x86-64") Co-Developed-by: Rick Edgecombe Signed-off-by: Daniel Borkmann Acked-by: Alexei Starovoitov Cc: Eric Dumazet Cc: Jann Horn Cc: Kees Cook Cc: LKML Signed-off-by: Alexei Starovoitov Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman

bpf: get rid of pure_initcall dependency to enable jits

2019-08-25T08:50:02Z

commit fa9dd599b4dae841924b022768354cfde9affecb upstream. Having a pure_initcall() callback just to permanently enable BPF JITs under CONFIG_BPF_JIT_ALWAYS_ON is unnecessary and could leave a small race window in future where JIT is still disabled on boot. Since we know about the setting at compilation time anyway, just initialize it properly there. Also consolidate all the individual bpf_jit_enable variables into a single one and move them under one location. Moreover, don't allow for setting unspecified garbage values on them. Signed-off-by: Daniel Borkmann Acked-by: Alexei Starovoitov Signed-off-by: Alexei Starovoitov [bwh: Backported to 4.14 as dependency of commit 2e4a30983b0f "bpf: restrict access to core bpf sysctls": - Adjust context] Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman

perf/core: Fix creating kernel counters for PMUs that override event->cpu

2019-08-16T08:13:55Z

[ Upstream commit 4ce54af8b33d3e21ca935fc1b89b58cbba956051 ] Some hardware PMU drivers will override perf_event.cpu inside their event_init callback. This causes a lockdep splat when initialized through the kernel API: WARNING: CPU: 0 PID: 250 at kernel/events/core.c:2917 ctx_sched_out+0x78/0x208 pc : ctx_sched_out+0x78/0x208 Call trace: ctx_sched_out+0x78/0x208 __perf_install_in_context+0x160/0x248 remote_function+0x58/0x68 generic_exec_single+0x100/0x180 smp_call_function_single+0x174/0x1b8 perf_install_in_context+0x178/0x188 perf_event_create_kernel_counter+0x118/0x160 Fix this by calling perf_install_in_context with event->cpu, just like perf_event_open Signed-off-by: Leonard Crestez Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Mark Rutland Cc: Alexander Shishkin Cc: Arnaldo Carvalho de Melo Cc: Frank Li Cc: Jiri Olsa Cc: Linus Torvalds Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Will Deacon Link: https://lkml.kernel.org/r/c4ebe0503623066896d7046def4d6b1e06e0eb2e.1563972056.git.leonard.crestez@nxp.com Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin

cgroup: Fix css_task_iter_advance_css_set() cset skip condition

2019-08-09T15:53:37Z

commit c596687a008b579c503afb7a64fcacc7270fae9e upstream. While adding handling for dying task group leaders c03cd7738a83 ("cgroup: Include dying leaders with live threads in PROCS iterations") added an inverted cset skip condition to css_task_iter_advance_css_set(). It should skip cset if it's completely empty but was incorrectly testing for the inverse condition for the dying_tasks list. Fix it. Signed-off-by: Tejun Heo Fixes: c03cd7738a83 ("cgroup: Include dying leaders with live threads in PROCS iterations") Reported-by: syzbot+d4bba5ccd4f9a2a68681@syzkaller.appspotmail.com Signed-off-by: Greg Kroah-Hartman

cgroup: css_task_iter_skip()'d iterators must be advanced before accessed

2019-08-09T15:53:36Z

commit cee0c33c546a93957a52ae9ab6bebadbee765ec5 upstream. b636fd38dc40 ("cgroup: Implement css_task_iter_skip()") introduced css_task_iter_skip() which is used to fix task iterations skipping dying threadgroup leaders with live threads. Skipping is implemented as a subportion of full advancing but css_task_iter_next() forgot to fully advance a skipped iterator before determining the next task to visit causing it to return invalid task pointers. Fix it by making css_task_iter_next() fully advance the iterator if it has been skipped since the previous iteration. Signed-off-by: Tejun Heo Reported-by: syzbot Link: http://lkml.kernel.org/r/00000000000097025d058a7fd785@google.com Fixes: b636fd38dc40 ("cgroup: Implement css_task_iter_skip()") Signed-off-by: Greg Kroah-Hartman

cgroup: Include dying leaders with live threads in PROCS iterations

2019-08-09T15:53:36Z

commit c03cd7738a83b13739f00546166969342c8ff014 upstream. CSS_TASK_ITER_PROCS currently iterates live group leaders; however, this means that a process with dying leader and live threads will be skipped. IOW, cgroup.procs might be empty while cgroup.threads isn't, which is confusing to say the least. Fix it by making cset track dying tasks and include dying leaders with live threads in PROCS iteration. Signed-off-by: Tejun Heo Reported-and-tested-by: Topi Miettinen Cc: Oleg Nesterov Signed-off-by: Greg Kroah-Hartman

cgroup: Implement css_task_iter_skip()

2019-08-09T15:53:36Z

commit b636fd38dc40113f853337a7d2a6885ad23b8811 upstream. When a task is moved out of a cset, task iterators pointing to the task are advanced using the normal css_task_iter_advance() call. This is fine but we'll be tracking dying tasks on csets and thus moving tasks from cset->tasks to (to be added) cset->dying_tasks. When we remove a task from cset->tasks, if we advance the iterators, they may move over to the next cset before we had the chance to add the task back on the dying list, which can allow the task to escape iteration. This patch separates out skipping from advancing. Skipping only moves the affected iterators to the next pointer rather than fully advancing it and the following advancing will recognize that the cursor has already been moved forward and do the rest of advancing. This ensures that when a task moves from one list to another in its cset, as long as it moves in the right direction, it's always visible to iteration. This doesn't cause any visible behavior changes. Signed-off-by: Tejun Heo Cc: Oleg Nesterov Signed-off-by: Greg Kroah-Hartman

cgroup: Call cgroup_release() before __exit_signal()

2019-08-09T15:53:36Z

commit 6b115bf58e6f013ca75e7115aabcbd56c20ff31d upstream. cgroup_release() calls cgroup_subsys->release() which is used by the pids controller to uncharge its pid. We want to use it to manage iteration of dying tasks which requires putting it before __unhash_process(). Move cgroup_release() above __exit_signal(). While this makes it uncharge before the pid is freed, pid is RCU freed anyway and the window is very narrow. Signed-off-by: Tejun Heo Cc: Oleg Nesterov Signed-off-by: Greg Kroah-Hartman