user/sven/linux.git/include/linux/cgroup.h, branch v5.15.103

memcg: fix possible use-after-free in memcg_write_event_control()

2022-12-14T10:37:19Z

commit 4a7ba45b1a435e7097ca0f79a847d0949d0eb088 upstream. memcg_write_event_control() accesses the dentry->d_name of the specified control fd to route the write call. As a cgroup interface file can't be renamed, it's safe to access d_name as long as the specified file is a regular cgroup file. Also, as these cgroup interface files can't be removed before the directory, it's safe to access the parent too. Prior to 347c4a874710 ("memcg: remove cgroup_event->cft"), there was a call to __file_cft() which verified that the specified file is a regular cgroupfs file before further accesses. The cftype pointer returned from __file_cft() was no longer necessary and the commit inadvertently dropped the file type check with it allowing any file to slip through. With the invarients broken, the d_name and parent accesses can now race against renames and removals of arbitrary files and cause use-after-free's. Fix the bug by resurrecting the file type check in __file_cft(). Now that cgroupfs is implemented through kernfs, checking the file operations needs to go through a layer of indirection. Instead, let's check the superblock and dentry type. Link: https://lkml.kernel.org/r/Y5FRm/cfcKPGzWwl@slm.duckdns.org Fixes: 347c4a874710 ("memcg: remove cgroup_event->cft") Signed-off-by: Tejun Heo Reported-by: Jann Horn Acked-by: Roman Gushchin Acked-by: Johannes Weiner Cc: Linus Torvalds Cc: Michal Hocko Cc: Muchun Song Cc: Shakeel Butt Cc: [3.14+] Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

bpf, cgroups: Fix cgroup v2 fallback on v1/v2 mixed mode

2021-09-13T23:35:58Z

Fix cgroup v1 interference when non-root cgroup v2 BPF programs are used. Back in the days, commit bd1060a1d671 ("sock, cgroup: add sock->sk_cgroup") embedded per-socket cgroup information into sock->sk_cgrp_data and in order to save 8 bytes in struct sock made both mutually exclusive, that is, when cgroup v1 socket tagging (e.g. net_cls/net_prio) is used, then cgroup v2 falls back to the root cgroup in sock_cgroup_ptr() (&cgrp_dfl_root.cgrp). The assumption made was "there is no reason to mix the two and this is in line with how legacy and v2 compatibility is handled" as stated in bd1060a1d671. However, with Kubernetes more widely supporting cgroups v2 as well nowadays, this assumption no longer holds, and the possibility of the v1/v2 mixed mode with the v2 root fallback being hit becomes a real security issue. Many of the cgroup v2 BPF programs are also used for policy enforcement, just to pick _one_ example, that is, to programmatically deny socket related system calls like connect(2) or bind(2). A v2 root fallback would implicitly cause a policy bypass for the affected Pods. In production environments, we have recently seen this case due to various circumstances: i) a different 3rd party agent and/or ii) a container runtime such as [0] in the user's environment configuring legacy cgroup v1 net_cls tags, which triggered implicitly mentioned root fallback. Another case is Kubernetes projects like kind [1] which create Kubernetes nodes in a container and also add cgroup namespaces to the mix, meaning programs which are attached to the cgroup v2 root of the cgroup namespace get attached to a non-root cgroup v2 path from init namespace point of view. And the latter's root is out of reach for agents on a kind Kubernetes node to configure. Meaning, any entity on the node setting cgroup v1 net_cls tag will trigger the bypass despite cgroup v2 BPF programs attached to the namespace root. Generally, this mutual exclusiveness does not hold anymore in today's user environments and makes cgroup v2 usage from BPF side fragile and unreliable. This fix adds proper struct cgroup pointer for the cgroup v2 case to struct sock_cgroup_data in order to address these issues; this implicitly also fixes the tradeoffs being made back then with regards to races and refcount leaks as stated in bd1060a1d671, and removes the fallback, so that cgroup v2 BPF programs always operate as expected. [0] https://github.com/nestybox/sysbox/ [1] https://kind.sigs.k8s.io/ Fixes: bd1060a1d671 ("sock, cgroup: add sock->sk_cgroup") Signed-off-by: Daniel Borkmann Signed-off-by: Alexei Starovoitov Acked-by: Stanislav Fomichev Acked-by: Tejun Heo Link: https://lore.kernel.org/bpf/20210913230759.2313-1-daniel@iogearbox.net

Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

2021-07-02T22:14:36Z

Pull SCSI updates from James Bottomley: "This series consists of the usual driver updates (ufs, ibmvfc, megaraid_sas, lpfc, elx, mpi3mr, qedi, iscsi, storvsc, mpt3sas) with elx and mpi3mr being new drivers. The major core change is a rework to drop the status byte handling macros and the old bit shifted definitions and the rest of the updates are minor fixes" * tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (287 commits) scsi: aha1740: Avoid over-read of sense buffer scsi: arcmsr: Avoid over-read of sense buffer scsi: ips: Avoid over-read of sense buffer scsi: ufs: ufs-mediatek: Add missing of_node_put() in ufs_mtk_probe() scsi: elx: libefc: Fix IRQ restore in efc_domain_dispatch_frame() scsi: elx: libefc: Fix less than zero comparison of a unsigned int scsi: elx: efct: Fix pointer error checking in debugfs init scsi: elx: efct: Fix is_originator return code type scsi: elx: efct: Fix link error for _bad_cmpxchg scsi: elx: efct: Eliminate unnecessary boolean check in efct_hw_command_cancel() scsi: elx: efct: Do not use id uninitialized in efct_lio_setup_session() scsi: elx: efct: Fix error handling in efct_hw_init() scsi: elx: efct: Remove redundant initialization of variable lun scsi: elx: efct: Fix spelling mistake "Unexected" -> "Unexpected" scsi: lpfc: Fix build error in lpfc_scsi.c scsi: target: iscsi: Remove redundant continue statement scsi: qla4xxx: Remove redundant continue statement scsi: ppa: Switch to use module_parport_driver() scsi: imm: Switch to use module_parport_driver() scsi: mpt3sas: Fix error return value in _scsih_expander_add() ...

scsi: cgroup: Add cgroup_get_from_id()

2021-06-10T14:01:31Z

Add a new function, cgroup_get_from_id(), to retrieve the cgroup associated with a cgroup id. Also export the function cgroup_get_e_css() as this is needed in blk-cgroup.h. Link: https://lore.kernel.org/r/20210608043556.274139-2-muneendra.kumar@broadcom.com Reviewed-by: Himanshu Madhani Reviewed-by: Hannes Reinecke Acked-by: Tejun Heo Signed-off-by: Muneendra Kumar Signed-off-by: Martin K. Petersen

cgroup: make per-cgroup pressure stall tracking configurable

2021-06-08T18:59:02Z

PSI accounts stalls for each cgroup separately and aggregates it at each level of the hierarchy. This causes additional overhead with psi_avgs_work being called for each cgroup in the hierarchy. psi_avgs_work has been highly optimized, however on systems with large number of cgroups the overhead becomes noticeable. Systems which use PSI only at the system level could avoid this overhead if PSI can be configured to skip per-cgroup stall accounting. Add "cgroup_disable=pressure" kernel command-line option to allow requesting system-wide only pressure stall accounting. When set, it keeps system-wide accounting under /proc/pressure/ but skips accounting for individual cgroups and does not expose PSI nodes in cgroup hierarchy. Signed-off-by: Suren Baghdasaryan Acked-by: Peter Zijlstra (Intel) Acked-by: Johannes Weiner Signed-off-by: Tejun Heo

Merge branch 'for-5.13-fixes' into for-5.14

2021-05-24T17:43:56Z

cgroup: fix spelling mistakes

2021-05-24T16:45:26Z

Fix some spelling mistakes in comments: hierarhcy ==> hierarchy automtically ==> automatically overriden ==> overridden In absense of .. or ==> In absence of .. and assocaited ==> associated taget ==> target initate ==> initiate succeded ==> succeeded curremt ==> current udpated ==> updated Signed-off-by: Zhen Lei Signed-off-by: Tejun Heo

cgroup: inline cgroup_task_freeze()

2021-05-11T01:31:03Z

After the introduction of the cgroup.kill there is only one call site of cgroup_task_freeze() left: cgroup_exit(). cgroup_task_freeze() is currently taking rcu_read_lock() to read task's cgroup flags, but because it's always called with css_set_lock locked, the rcu protection is excessive. Simplify the code by inlining cgroup_task_freeze(). v2: fix build Signed-off-by: Roman Gushchin Reviewed-by: Shakeel Butt Signed-off-by: Tejun Heo

rbtree, perf: Use new rbtree helpers

2021-02-17T13:07:48Z

Reduce rbtree boiler plate by using the new helpers. One noteworthy change is unification of the various (partial) compare functions. We construct a subtree match by forcing the sub-order to always match, see __group_cmp(). Due to 'const' we had to touch cgroup_id(). Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Acked-by: Tejun Heo Acked-by: Davidlohr Bueso

cgroup: Use generic ns_common::count

2020-08-19T12:14:29Z

Switch over cgroup namespaces to use the newly introduced common lifetime counter. Currently every namespace type has its own lifetime counter which is stored in the specific namespace struct. The lifetime counters are used identically for all namespaces types. Namespaces may of course have additional unrelated counters and these are not altered. This introduces a common lifetime counter into struct ns_common. The ns_common struct encompasses information that all namespaces share. That should include the lifetime counter since its common for all of them. It also allows us to unify the type of the counters across all namespaces. Most of them use refcount_t but one uses atomic_t and at least one uses kref. Especially the last one doesn't make much sense since it's just a wrapper around refcount_t since 2016 and actually complicates cleanup operations by having to use container_of() to cast the correct namespace struct out of struct ns_common. Having the lifetime counter for the namespaces in one place reduces maintenance cost. Not just because after switching all namespaces over we will have removed more code than we added but also because the logic is more easily understandable and we indicate to the user that the basic lifetime requirements for all namespaces are currently identical. Signed-off-by: Kirill Tkhai Reviewed-by: Kees Cook Acked-by: Christian Brauner Link: https://lore.kernel.org/r/159644980994.604812.383801057081594972.stgit@localhost.localdomain Signed-off-by: Christian Brauner