user/sven/linux.git/kernel, branch v5.2.2

genirq: Add optional hardware synchronization for shutdown

2019-07-21T07:00:39Z

commit 62e0468650c30f0298822c580f382b16328119f6 upstream. free_irq() ensures that no hardware interrupt handler is executing on a different CPU before actually releasing resources and deactivating the interrupt completely in a domain hierarchy. But that does not catch the case where the interrupt is on flight at the hardware level but not yet serviced by the target CPU. That creates an interesing race condition: CPU 0 CPU 1 IRQ CHIP interrupt is raised sent to CPU1 Unable to handle immediately (interrupts off, deep idle delay) mask() ... free() shutdown() synchronize_irq() release_resources() do_IRQ() -> resources are not available That might be harmless and just trigger a spurious interrupt warning, but some interrupt chips might get into a wedged state. Utilize the existing irq_get_irqchip_state() callback for the synchronization in free_irq(). synchronize_hardirq() is not using this mechanism as it might actually deadlock unter certain conditions, e.g. when called with interrupts disabled and the target CPU is the one on which the synchronization is invoked. synchronize_irq() uses it because that function cannot be called from non preemtible contexts as it might sleep. No functional change intended and according to Marc the existing GIC implementations where the driver supports the callback should be able to cope with that core change. Famous last words. Fixes: 464d12309e1b ("x86/vector: Switch IOAPIC to global reservation mode") Reported-by: Robert Hodaszi Signed-off-by: Thomas Gleixner Reviewed-by: Marc Zyngier Tested-by: Marc Zyngier Link: https://lkml.kernel.org/r/20190628111440.279463375@linutronix.de Signed-off-by: Greg Kroah-Hartman

genirq: Fix misleading synchronize_irq() documentation

2019-07-21T07:00:39Z

commit 1d21f2af8571c6a6a44e7c1911780614847b0253 upstream. The function might sleep, so it cannot be called from interrupt context. Not even with care. Signed-off-by: Thomas Gleixner Cc: Marc Zyngier Link: https://lkml.kernel.org/r/20190628111440.189241552@linutronix.de Signed-off-by: Greg Kroah-Hartman

genirq: Delay deactivation in free_irq()

2019-07-21T07:00:39Z

commit 4001d8e8762f57d418b66e4e668601791900a1dd upstream. When interrupts are shutdown, they are immediately deactivated in the irqdomain hierarchy. While this looks obviously correct there is a subtle issue: There might be an interrupt in flight when free_irq() is invoking the shutdown. This is properly handled at the irq descriptor / primary handler level, but the deactivation might completely disable resources which are required to acknowledge the interrupt. Split the shutdown code and deactivate the interrupt after synchronization in free_irq(). Fixup all other usage sites where this is not an issue to invoke the combined shutdown_and_deactivate() function instead. This still might be an issue if the interrupt in flight servicing is delayed on a remote CPU beyond the invocation of synchronize_irq(), but that cannot be handled at that level and needs to be handled in the synchronize_irq() context. Fixes: f8264e34965a ("irqdomain: Introduce new interfaces to support hierarchy irqdomains") Reported-by: Robert Hodaszi Signed-off-by: Thomas Gleixner Reviewed-by: Marc Zyngier Link: https://lkml.kernel.org/r/20190628111440.098196390@linutronix.de Signed-off-by: Greg Kroah-Hartman

ptrace: Fix ->ptracer_cred handling for PTRACE_TRACEME

2019-07-04T17:00:41Z

Fix two issues: When called for PTRACE_TRACEME, ptrace_link() would obtain an RCU reference to the parent's objective credentials, then give that pointer to get_cred(). However, the object lifetime rules for things like struct cred do not permit unconditionally turning an RCU reference into a stable reference. PTRACE_TRACEME records the parent's credentials as if the parent was acting as the subject, but that's not the case. If a malicious unprivileged child uses PTRACE_TRACEME and the parent is privileged, and at a later point, the parent process becomes attacker-controlled (because it drops privileges and calls execve()), the attacker ends up with control over two processes with a privileged ptrace relationship, which can be abused to ptrace a suid binary and obtain root privileges. Fix both of these by always recording the credentials of the process that is requesting the creation of the ptrace relationship: current_cred() can't change under us, and current is the proper subject for access control. This change is theoretically userspace-visible, but I am not aware of any code that it will actually break. Fixes: 64b875f7ac8a ("ptrace: Capture the ptracer's creds not PT_PTRACE_CAP") Signed-off-by: Jann Horn Acked-by: Oleg Nesterov Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds

Merge tag 'trace-v5.2-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2019-07-04T01:26:17Z

Pull tracing fixes from Steven Rostedt: "This includes three fixes: - Fix a deadlock from a previous fix to keep module loading and function tracing text modifications from stepping on each other (this has a few patches to help document the issue in comments) - Fix a crash when the snapshot buffer gets out of sync with the main ring buffer - Fix a memory leak when reading the memory logs" * tag 'trace-v5.2-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ftrace/x86: Anotate text_mutex split between ftrace_arch_code_modify_post_process() and ftrace_arch_code_modify_prepare() tracing/snapshot: Resize spare buffer if size changed tracing: Fix memory leak in tracing_err_log_open() ftrace/x86: Add a comment to why we take text_mutex in ftrace_arch_code_modify_prepare() ftrace/x86: Remove possible deadlock between register_kprobe() and ftrace_run_update_code()

fork: return proper negative error code

2019-07-01T14:43:30Z

Make sure to return a proper negative error code from copy_process() when anon_inode_getfile() fails with CLONE_PIDFD. Otherwise _do_fork() will not detect an error and get_task_pid() will operator on a nonsensical pointer: R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c R13: 00007ffc15fbb0ff R14: 00007ff07e47e9c0 R15: 0000000000000000 kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 7990 Comm: syz-executor290 Not tainted 5.2.0-rc6+ #9 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__read_once_size include/linux/compiler.h:194 [inline] RIP: 0010:get_task_pid+0xe1/0x210 kernel/pid.c:372 Code: 89 ff e8 62 27 5f 00 49 8b 07 44 89 f1 4c 8d bc c8 90 01 00 00 eb 0c e8 0d fe 25 00 49 81 c7 38 05 00 00 4c 89 f8 48 c1 e8 03 <80> 3c 18 00 74 08 4c 89 ff e8 31 27 5f 00 4d 8b 37 e8 f9 47 12 00 RSP: 0018:ffff88808a4a7d78 EFLAGS: 00010203 RAX: 00000000000000a7 RBX: dffffc0000000000 RCX: ffff888088180600 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88808a4a7d90 R08: ffffffff814fb3a8 R09: ffffed1015d66bf8 R10: ffffed1015d66bf8 R11: 1ffff11015d66bf7 R12: 0000000000041ffc R13: 1ffff11011494fbc R14: 0000000000000000 R15: 000000000000053d FS: 00007ff07e47e700(0000) GS:ffff8880aeb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000004b5100 CR3: 0000000094df2000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: _do_fork+0x1b9/0x5f0 kernel/fork.c:2360 __do_sys_clone kernel/fork.c:2454 [inline] __se_sys_clone kernel/fork.c:2448 [inline] __x64_sys_clone+0xc1/0xd0 kernel/fork.c:2448 do_syscall_64+0xfe/0x140 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe Link: https://lore.kernel.org/lkml/000000000000e0dc0d058c9e7142@google.com Reported-and-tested-by: syzbot+002e636502bc4b64eb5c@syzkaller.appspotmail.com Fixes: 6fd2fe494b17 ("copy_process(): don't use ksys_close() on cleanups") Cc: Jann Horn Cc: Al Viro Signed-off-by: Christian Brauner

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

2019-06-30T03:19:17Z

Pull SMP fixes from Thomas Gleixner: "Two small changes for the cpu hotplug code: - Prevent out of bounds access which actually might crash the machine caused by a missing bounds check in the fail injection code - Warn about unsupported migitation mode command line arguments to make people aware that they typoed the paramater. Not necessarily a fix but quite some people tripped over that" * 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: cpu/hotplug: Fix out-of-bounds read when setting fail state cpu/speculation: Warn on unsupported mitigations= parameter

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

2019-06-29T11:39:17Z

Pull perf fixes from Ingo Molnar: "Various fixes, most of them related to bugs perf fuzzing found in the x86 code" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/regs: Use PERF_REG_EXTENDED_MASK perf/x86: Remove pmu->pebs_no_xmm_regs perf/x86: Clean up PEBS_XMM_REGS perf/x86/regs: Check reserved bits perf/x86: Disable extended registers for non-supported PMUs perf/ioctl: Add check for the sample_period value perf/core: Fix perf_sample_regs_user() mm check

Merge tag 'pm-5.2-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

2019-06-29T11:29:45Z

Pull power management fix from Rafael Wysocki: "Avoid skipping bus-level PCI power management during system resume for PCIe ports left in D0 during the preceding suspend transition on platforms where the power states of those ports can change out of the PCI layer's control" * tag 'pm-5.2-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: PCI: PM: Avoid skipping bus-level PM on platforms without ACPI

fork,memcg: alloc_thread_stack_node needs to set tsk->stack

2019-06-29T08:43:45Z

Commit 5eed6f1dff87 ("fork,memcg: fix crash in free_thread_stack on memcg charge fail") corrected two instances, but there was a third instance of this bug. Without setting tsk->stack, if memcg_charge_kernel_stack fails, it'll execute free_thread_stack() on a dangling pointer. Enterprise kernels are compiled with VMAP_STACK=y so this isn't critical, but custom VMAP_STACK=n builds should have some performance advantage, with the drawback of risking to fail fork because compaction didn't succeed. So as long as VMAP_STACK=n is a supported option it's worth fixing it upstream. Link: http://lkml.kernel.org/r/20190619011450.28048-1-aarcange@redhat.com Fixes: 9b6f7e163cd0 ("mm: rework memcg kernel stack accounting") Signed-off-by: Andrea Arcangeli Reviewed-by: Rik van Riel Acked-by: Roman Gushchin Acked-by: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds