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2012-07-30kernel/sys.c: avoid argv_free(NULL)Andrew Morton
If argv_split() failed, the code will end up calling argv_free(NULL). Fix it up and clean things up a bit. Addresses Coverity report 703573. Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Kees Cook <keescook@chromium.org> Cc: Serge Hallyn <serge.hallyn@canonical.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: WANG Cong <xiyou.wangcong@gmail.com> Cc: Alan Cox <alan@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-30prctl: remove redunant assignment of "error" to zeroSasikantha babu
Just setting the "error" to error number is enough on failure and It doesn't require to set "error" variable to zero in each switch case, since it was already initialized with zero. And also removed return 0 in switch case with break statement Signed-off-by: Sasikantha babu <sasikanth.v19@gmail.com> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Serge E. Hallyn <serge@hallyn.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-11c/r: prctl: less paranoid prctl_set_mm_exe_file()Konstantin Khlebnikov
"no other files mapped" requirement from my previous patch (c/r: prctl: update prctl_set_mm_exe_file() after mm->num_exe_file_vmas removal) is too paranoid, it forbids operation even if there mapped one shared-anon vma. Let's check that current mm->exe_file already unmapped, in this case exe_file symlink already outdated and its changing is reasonable. Plus, this patch fixes exit code in case operation success. Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Reported-by: Cyrill Gorcunov <gorcunov@openvz.org> Tested-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Kees Cook <keescook@chromium.org> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Tejun Heo <tj@kernel.org> Cc: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-20c/r: prctl: Move PR_GET_TID_ADDRESS to a proper placeCyrill Gorcunov
During merging of PR_GET_TID_ADDRESS patch the code has been misplaced (it happened to appear under PR_MCE_KILL) in result noone can use this option. Fix it by moving code snippet to a proper place. Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Acked-by: Kees Cook <keescook@chromium.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Andrey Vagin <avagin@openvz.org> Cc: Serge Hallyn <serge.hallyn@canonical.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-07c/r: prctl: drop VMA flags test on PR_SET_MM_ stack data assignmentCyrill Gorcunov
In commit b76437579d13 ("procfs: mark thread stack correctly in proc/<pid>/maps") the stack allocated via clone() is marked in /proc/<pid>/maps as [stack:%d] thus it might be out of the former mm->start_stack/end_stack values (and even has some custom VMA flags set). So to be able to restore mm->start_stack/end_stack drop vma flags test, but still require the underlying VMA to exist. As always note this feature is under CONFIG_CHECKPOINT_RESTORE and requires CAP_SYS_RESOURCE to be granted. Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Oleg Nesterov <oleg@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Serge Hallyn <serge.hallyn@canonical.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-07c/r: prctl: add ability to get clear_tid_addressCyrill Gorcunov
Zero is written at clear_tid_address when the process exits. This functionality is used by pthread_join(). We already have sys_set_tid_address() to change this address for the current task but there is no way to obtain it from user space. Without the ability to find this address and dump it we can't restore pthread'ed apps which call pthread_join() once they have been restored. This patch introduces the PR_GET_TID_ADDRESS prctl option which allows the current process to obtain own clear_tid_address. This feature is available iif CONFIG_CHECKPOINT_RESTORE is set. [akpm@linux-foundation.org: fix prctl numbering] Signed-off-by: Andrew Vagin <avagin@openvz.org> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Pedro Alves <palves@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Tejun Heo <tj@kernel.org> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-07c/r: prctl: add minimal address test to PR_SET_MMCyrill Gorcunov
Make sure the address being set is greater than mmap_min_addr (as suggested by Kees Cook). Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Acked-by: Kees Cook <keescook@chromium.org> Cc: Serge Hallyn <serge.hallyn@canonical.com> Cc: Tejun Heo <tj@kernel.org> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-07c/r: prctl: update prctl_set_mm_exe_file() after mm->num_exe_file_vmas removalKonstantin Khlebnikov
A fix for commit b32dfe377102 ("c/r: prctl: add ability to set new mm_struct::exe_file"). After removing mm->num_exe_file_vmas kernel keeps mm->exe_file until final mmput(), it never becomes NULL while task is alive. We can check for other mapped files in mm instead of checking mm->num_exe_file_vmas, and mark mm with flag MMF_EXE_FILE_CHANGED in order to forbid second changing of mm->exe_file. Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Kees Cook <keescook@chromium.org> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Tejun Heo <tj@kernel.org> Cc: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-31c/r: prctl: add ability to set new mm_struct::exe_fileCyrill Gorcunov
When we do restore we would like to have a way to setup a former mm_struct::exe_file so that /proc/pid/exe would point to the original executable file a process had at checkpoint time. For this the PR_SET_MM_EXE_FILE code is introduced. This option takes a file descriptor which will be set as a source for new /proc/$pid/exe symlink. Note it allows to change /proc/$pid/exe if there are no VM_EXECUTABLE vmas present for current process, simply because this feature is a special to C/R and mm::num_exe_file_vmas become meaningless after that. To minimize the amount of transition the /proc/pid/exe symlink might have, this feature is implemented in one-shot manner. Thus once changed the symlink can't be changed again. This should help sysadmins to monitor the symlinks over all process running in a system. In particular one could make a snapshot of processes and ring alarm if there unexpected changes of /proc/pid/exe's in a system. Note -- this feature is available iif CONFIG_CHECKPOINT_RESTORE is set and the caller must have CAP_SYS_RESOURCE capability granted, otherwise the request to change symlink will be rejected. Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Kees Cook <keescook@chromium.org> Cc: Tejun Heo <tj@kernel.org> Cc: Matt Helsley <matthltc@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-31c/r: prctl: extend PR_SET_MM to set up more mm_struct entriesCyrill Gorcunov
During checkpoint we dump whole process memory to a file and the dump includes process stack memory. But among stack data itself, the stack carries additional parameters such as command line arguments, environment data and auxiliary vector. So when we do restore procedure and once we've restored stack data itself we need to setup mm_struct::arg_start/end, env_start/end, so restored process would be able to find command line arguments and environment data it had at checkpoint time. The same applies to auxiliary vector. For this reason additional PR_SET_MM_(ARG_START | ARG_END | ENV_START | ENV_END | AUXV) codes are introduced. Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Acked-by: Kees Cook <keescook@chromium.org> Cc: Tejun Heo <tj@kernel.org> Cc: Andrew Vagin <avagin@openvz.org> Cc: Serge Hallyn <serge.hallyn@canonical.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Vasiliy Kulikov <segoon@openwall.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-31kmod: convert two call sites to call_usermodehelper_fns()Boaz Harrosh
Both kernel/sys.c && security/keys/request_key.c where inlining the exact same code as call_usermodehelper_fns(); So simply convert these sites to directly use call_usermodehelper_fns(). Signed-off-by: Boaz Harrosh <bharrosh@panasas.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-31sethostname/setdomainname: notify userspace when there is a change in ↵Sasikantha babu
uts_kern_table sethostname() and setdomainname() notify userspace on failure (without modifying uts_kern_table). Change things so that we only notify userspace on success, when uts_kern_table was actually modified. Signed-off-by: Sasikantha babu <sasikanth.v19@gmail.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: WANG Cong <amwang@redhat.com> Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-23Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull user namespace enhancements from Eric Biederman: "This is a course correction for the user namespace, so that we can reach an inexpensive, maintainable, and reasonably complete implementation. Highlights: - Config guards make it impossible to enable the user namespace and code that has not been converted to be user namespace safe. - Use of the new kuid_t type ensures the if you somehow get past the config guards the kernel will encounter type errors if you enable user namespaces and attempt to compile in code whose permission checks have not been updated to be user namespace safe. - All uids from child user namespaces are mapped into the initial user namespace before they are processed. Removing the need to add an additional check to see if the user namespace of the compared uids remains the same. - With the user namespaces compiled out the performance is as good or better than it is today. - For most operations absolutely nothing changes performance or operationally with the user namespace enabled. - The worst case performance I could come up with was timing 1 billion cache cold stat operations with the user namespace code enabled. This went from 156s to 164s on my laptop (or 156ns to 164ns per stat operation). - (uid_t)-1 and (gid_t)-1 are reserved as an internal error value. Most uid/gid setting system calls treat these value specially anyway so attempting to use -1 as a uid would likely cause entertaining failures in userspace. - If setuid is called with a uid that can not be mapped setuid fails. I have looked at sendmail, login, ssh and every other program I could think of that would call setuid and they all check for and handle the case where setuid fails. - If stat or a similar system call is called from a context in which we can not map a uid we lie and return overflowuid. The LFS experience suggests not lying and returning an error code might be better, but the historical precedent with uids is different and I can not think of anything that would break by lying about a uid we can't map. - Capabilities are localized to the current user namespace making it safe to give the initial user in a user namespace all capabilities. My git tree covers all of the modifications needed to convert the core kernel and enough changes to make a system bootable to runlevel 1." Fix up trivial conflicts due to nearby independent changes in fs/stat.c * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (46 commits) userns: Silence silly gcc warning. cred: use correct cred accessor with regards to rcu read lock userns: Convert the move_pages, and migrate_pages permission checks to use uid_eq userns: Convert cgroup permission checks to use uid_eq userns: Convert tmpfs to use kuid and kgid where appropriate userns: Convert sysfs to use kgid/kuid where appropriate userns: Convert sysctl permission checks to use kuid and kgids. userns: Convert proc to use kuid/kgid where appropriate userns: Convert ext4 to user kuid/kgid where appropriate userns: Convert ext3 to use kuid/kgid where appropriate userns: Convert ext2 to use kuid/kgid where appropriate. userns: Convert devpts to use kuid/kgid where appropriate userns: Convert binary formats to use kuid/kgid where appropriate userns: Add negative depends on entries to avoid building code that is userns unsafe userns: signal remove unnecessary map_cred_ns userns: Teach inode_capable to understand inodes whose uids map to other namespaces. userns: Fail exec for suid and sgid binaries with ids outside our user namespace. userns: Convert stat to return values mapped from kuids and kgids userns: Convert user specfied uids and gids in chown into kuids and kgid userns: Use uid_eq gid_eq helpers when comparing kuids and kgids in the vfs ...
2012-05-03userns: Convert ptrace, kill, set_priority permission checks to work with ↵Eric W. Biederman
kuids and kgids Update the permission checks to use the new uid_eq and gid_eq helpers and remove the now unnecessary user_ns equality comparison. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-05-03userns: Convert setting and getting uid and gid system calls to use kuid and ↵Eric W. Biederman
kgid Convert setregid, setgid, setreuid, setuid, setresuid, getresuid, setresgid, getresgid, setfsuid, setfsgid, getuid, geteuid, getgid, getegid, waitpid, waitid, wait4. Convert userspace uids and gids into kuids and kgids before being placed on struct cred. Convert struct cred kuids and kgids into userspace uids and gids when returning them. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-05-03userns: Store uid and gid values in struct cred with kuid_t and kgid_t typesEric W. Biederman
cred.h and a few trivial users of struct cred are changed. The rest of the users of struct cred are left for other patches as there are too many changes to make in one go and leave the change reviewable. If the user namespace is disabled and CONFIG_UIDGID_STRICT_TYPE_CHECKS are disabled the code will contiue to compile and behave correctly. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-04-14seccomp: add system call filtering using BPFWill Drewry
[This patch depends on luto@mit.edu's no_new_privs patch: https://lkml.org/lkml/2012/1/30/264 The whole series including Andrew's patches can be found here: https://github.com/redpig/linux/tree/seccomp Complete diff here: https://github.com/redpig/linux/compare/1dc65fed...seccomp ] This patch adds support for seccomp mode 2. Mode 2 introduces the ability for unprivileged processes to install system call filtering policy expressed in terms of a Berkeley Packet Filter (BPF) program. This program will be evaluated in the kernel for each system call the task makes and computes a result based on data in the format of struct seccomp_data. A filter program may be installed by calling: struct sock_fprog fprog = { ... }; ... prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &fprog); The return value of the filter program determines if the system call is allowed to proceed or denied. If the first filter program installed allows prctl(2) calls, then the above call may be made repeatedly by a task to further reduce its access to the kernel. All attached programs must be evaluated before a system call will be allowed to proceed. Filter programs will be inherited across fork/clone and execve. However, if the task attaching the filter is unprivileged (!CAP_SYS_ADMIN) the no_new_privs bit will be set on the task. This ensures that unprivileged tasks cannot attach filters that affect privileged tasks (e.g., setuid binary). There are a number of benefits to this approach. A few of which are as follows: - BPF has been exposed to userland for a long time - BPF optimization (and JIT'ing) are well understood - Userland already knows its ABI: system call numbers and desired arguments - No time-of-check-time-of-use vulnerable data accesses are possible. - system call arguments are loaded on access only to minimize copying required for system call policy decisions. Mode 2 support is restricted to architectures that enable HAVE_ARCH_SECCOMP_FILTER. In this patch, the primary dependency is on syscall_get_arguments(). The full desired scope of this feature will add a few minor additional requirements expressed later in this series. Based on discussion, SECCOMP_RET_ERRNO and SECCOMP_RET_TRACE seem to be the desired additional functionality. No architectures are enabled in this patch. Signed-off-by: Will Drewry <wad@chromium.org> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Reviewed-by: Indan Zupancic <indan@nul.nu> Acked-by: Eric Paris <eparis@redhat.com> Reviewed-by: Kees Cook <keescook@chromium.org> v18: - rebase to v3.4-rc2 - s/chk/check/ (akpm@linux-foundation.org,jmorris@namei.org) - allocate with GFP_KERNEL|__GFP_NOWARN (indan@nul.nu) - add a comment for get_u32 regarding endianness (akpm@) - fix other typos, style mistakes (akpm@) - added acked-by v17: - properly guard seccomp filter needed headers (leann@ubuntu.com) - tighten return mask to 0x7fff0000 v16: - no change v15: - add a 4 instr penalty when counting a path to account for seccomp_filter size (indan@nul.nu) - drop the max insns to 256KB (indan@nul.nu) - return ENOMEM if the max insns limit has been hit (indan@nul.nu) - move IP checks after args (indan@nul.nu) - drop !user_filter check (indan@nul.nu) - only allow explicit bpf codes (indan@nul.nu) - exit_code -> exit_sig v14: - put/get_seccomp_filter takes struct task_struct (indan@nul.nu,keescook@chromium.org) - adds seccomp_chk_filter and drops general bpf_run/chk_filter user - add seccomp_bpf_load for use by net/core/filter.c - lower max per-process/per-hierarchy: 1MB - moved nnp/capability check prior to allocation (all of the above: indan@nul.nu) v13: - rebase on to 88ebdda6159ffc15699f204c33feb3e431bf9bdc v12: - added a maximum instruction count per path (indan@nul.nu,oleg@redhat.com) - removed copy_seccomp (keescook@chromium.org,indan@nul.nu) - reworded the prctl_set_seccomp comment (indan@nul.nu) v11: - reorder struct seccomp_data to allow future args expansion (hpa@zytor.com) - style clean up, @compat dropped, compat_sock_fprog32 (indan@nul.nu) - do_exit(SIGSYS) (keescook@chromium.org, luto@mit.edu) - pare down Kconfig doc reference. - extra comment clean up v10: - seccomp_data has changed again to be more aesthetically pleasing (hpa@zytor.com) - calling convention is noted in a new u32 field using syscall_get_arch. This allows for cross-calling convention tasks to use seccomp filters. (hpa@zytor.com) - lots of clean up (thanks, Indan!) v9: - n/a v8: - use bpf_chk_filter, bpf_run_filter. update load_fns - Lots of fixes courtesy of indan@nul.nu: -- fix up load behavior, compat fixups, and merge alloc code, -- renamed pc and dropped __packed, use bool compat. -- Added a hidden CONFIG_SECCOMP_FILTER to synthesize non-arch dependencies v7: (massive overhaul thanks to Indan, others) - added CONFIG_HAVE_ARCH_SECCOMP_FILTER - merged into seccomp.c - minimal seccomp_filter.h - no config option (part of seccomp) - no new prctl - doesn't break seccomp on systems without asm/syscall.h (works but arg access always fails) - dropped seccomp_init_task, extra free functions, ... - dropped the no-asm/syscall.h code paths - merges with network sk_run_filter and sk_chk_filter v6: - fix memory leak on attach compat check failure - require no_new_privs || CAP_SYS_ADMIN prior to filter installation. (luto@mit.edu) - s/seccomp_struct_/seccomp_/ for macros/functions (amwang@redhat.com) - cleaned up Kconfig (amwang@redhat.com) - on block, note if the call was compat (so the # means something) v5: - uses syscall_get_arguments (indan@nul.nu,oleg@redhat.com, mcgrathr@chromium.org) - uses union-based arg storage with hi/lo struct to handle endianness. Compromises between the two alternate proposals to minimize extra arg shuffling and account for endianness assuming userspace uses offsetof(). (mcgrathr@chromium.org, indan@nul.nu) - update Kconfig description - add include/seccomp_filter.h and add its installation - (naive) on-demand syscall argument loading - drop seccomp_t (eparis@redhat.com) v4: - adjusted prctl to make room for PR_[SG]ET_NO_NEW_PRIVS - now uses current->no_new_privs (luto@mit.edu,torvalds@linux-foundation.com) - assign names to seccomp modes (rdunlap@xenotime.net) - fix style issues (rdunlap@xenotime.net) - reworded Kconfig entry (rdunlap@xenotime.net) v3: - macros to inline (oleg@redhat.com) - init_task behavior fixed (oleg@redhat.com) - drop creator entry and extra NULL check (oleg@redhat.com) - alloc returns -EINVAL on bad sizing (serge.hallyn@canonical.com) - adds tentative use of "always_unprivileged" as per torvalds@linux-foundation.org and luto@mit.edu v2: - (patch 2 only) Signed-off-by: James Morris <james.l.morris@oracle.com>
2012-04-14Add PR_{GET,SET}_NO_NEW_PRIVS to prevent execve from granting privsAndy Lutomirski
With this change, calling prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0) disables privilege granting operations at execve-time. For example, a process will not be able to execute a setuid binary to change their uid or gid if this bit is set. The same is true for file capabilities. Additionally, LSM_UNSAFE_NO_NEW_PRIVS is defined to ensure that LSMs respect the requested behavior. To determine if the NO_NEW_PRIVS bit is set, a task may call prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0); It returns 1 if set and 0 if it is not set. If any of the arguments are non-zero, it will return -1 and set errno to -EINVAL. (PR_SET_NO_NEW_PRIVS behaves similarly.) This functionality is desired for the proposed seccomp filter patch series. By using PR_SET_NO_NEW_PRIVS, it allows a task to modify the system call behavior for itself and its child tasks without being able to impact the behavior of a more privileged task. Another potential use is making certain privileged operations unprivileged. For example, chroot may be considered "safe" if it cannot affect privileged tasks. Note, this patch causes execve to fail when PR_SET_NO_NEW_PRIVS is set and AppArmor is in use. It is fixed in a subsequent patch. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Will Drewry <wad@chromium.org> Acked-by: Eric Paris <eparis@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> v18: updated change desc v17: using new define values as per 3.4 Signed-off-by: James Morris <james.l.morris@oracle.com>
2012-04-07userns: Disassociate user_struct from the user_namespace.Eric W. Biederman
Modify alloc_uid to take a kuid and make the user hash table global. Stop holding a reference to the user namespace in struct user_struct. This simplifies the code and makes the per user accounting not care about which user namespace a uid happens to appear in. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-04-07userns: Add kuid_t and kgid_t and associated infrastructure in uidgid.hEric W. Biederman
Start distinguishing between internal kernel uids and gids and values that userspace can use. This is done by introducing two new types: kuid_t and kgid_t. These types and their associated functions are infrastructure are declared in the new header uidgid.h. Ultimately there will be a different implementation of the mapping functions for use with user namespaces. But to keep it simple we introduce the mapping functions first to separate the meat from the mechanical code conversions. Export overflowuid and overflowgid so we can use from_kuid_munged and from_kgid_munged in modular code. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-04-07userns: Use cred->user_ns instead of cred->user->user_nsEric W. Biederman
Optimize performance and prepare for the removal of the user_ns reference from user_struct. Remove the slow long walk through cred->user->user_ns and instead go straight to cred->user_ns. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-04-07userns: Remove unnecessary cast to struct user_struct when copying cred->user.Eric W. Biederman
In struct cred the user member is and has always been declared struct user_struct *user. At most a constant struct cred will have a constant pointer to non-constant user_struct so remove this unnecessary cast. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-03-28pidns: add reboot_pid_ns() to handle the reboot syscallDaniel Lezcano
In the case of a child pid namespace, rebooting the system does not really makes sense. When the pid namespace is used in conjunction with the other namespaces in order to create a linux container, the reboot syscall leads to some problems. A container can reboot the host. That can be fixed by dropping the sys_reboot capability but we are unable to correctly to poweroff/ halt/reboot a container and the container stays stuck at the shutdown time with the container's init process waiting indefinitively. After several attempts, no solution from userspace was found to reliabily handle the shutdown from a container. This patch propose to make the init process of the child pid namespace to exit with a signal status set to : SIGINT if the child pid namespace called "halt/poweroff" and SIGHUP if the child pid namespace called "reboot". When the reboot syscall is called and we are not in the initial pid namespace, we kill the pid namespace for "HALT", "POWEROFF", "RESTART", and "RESTART2". Otherwise we return EINVAL. Returning EINVAL is also an easy way to check if this feature is supported by the kernel when invoking another 'reboot' option like CAD. By this way the parent process of the child pid namespace knows if it rebooted or not and can take the right decision. Test case: ========== #include <alloca.h> #include <stdio.h> #include <sched.h> #include <unistd.h> #include <signal.h> #include <sys/reboot.h> #include <sys/types.h> #include <sys/wait.h> #include <linux/reboot.h> static int do_reboot(void *arg) { int *cmd = arg; if (reboot(*cmd)) printf("failed to reboot(%d): %m\n", *cmd); } int test_reboot(int cmd, int sig) { long stack_size = 4096; void *stack = alloca(stack_size) + stack_size; int status; pid_t ret; ret = clone(do_reboot, stack, CLONE_NEWPID | SIGCHLD, &cmd); if (ret < 0) { printf("failed to clone: %m\n"); return -1; } if (wait(&status) < 0) { printf("unexpected wait error: %m\n"); return -1; } if (!WIFSIGNALED(status)) { printf("child process exited but was not signaled\n"); return -1; } if (WTERMSIG(status) != sig) { printf("signal termination is not the one expected\n"); return -1; } return 0; } int main(int argc, char *argv[]) { int status; status = test_reboot(LINUX_REBOOT_CMD_RESTART, SIGHUP); if (status < 0) return 1; printf("reboot(LINUX_REBOOT_CMD_RESTART) succeed\n"); status = test_reboot(LINUX_REBOOT_CMD_RESTART2, SIGHUP); if (status < 0) return 1; printf("reboot(LINUX_REBOOT_CMD_RESTART2) succeed\n"); status = test_reboot(LINUX_REBOOT_CMD_HALT, SIGINT); if (status < 0) return 1; printf("reboot(LINUX_REBOOT_CMD_HALT) succeed\n"); status = test_reboot(LINUX_REBOOT_CMD_POWER_OFF, SIGINT); if (status < 0) return 1; printf("reboot(LINUX_REBOOT_CMD_POWERR_OFF) succeed\n"); status = test_reboot(LINUX_REBOOT_CMD_CAD_ON, -1); if (status >= 0) { printf("reboot(LINUX_REBOOT_CMD_CAD_ON) should have failed\n"); return 1; } printf("reboot(LINUX_REBOOT_CMD_CAD_ON) has failed as expected\n"); return 0; } [akpm@linux-foundation.org: tweak and add comments] [akpm@linux-foundation.org: checkpatch fixes] Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Tested-by: Serge Hallyn <serge.hallyn@canonical.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-23prctl: add PR_{SET,GET}_CHILD_SUBREAPER to allow simple process supervisionLennart Poettering
Userspace service managers/supervisors need to track their started services. Many services daemonize by double-forking and get implicitly re-parented to PID 1. The service manager will no longer be able to receive the SIGCHLD signals for them, and is no longer in charge of reaping the children with wait(). All information about the children is lost at the moment PID 1 cleans up the re-parented processes. With this prctl, a service manager process can mark itself as a sort of 'sub-init', able to stay as the parent for all orphaned processes created by the started services. All SIGCHLD signals will be delivered to the service manager. Receiving SIGCHLD and doing wait() is in cases of a service-manager much preferred over any possible asynchronous notification about specific PIDs, because the service manager has full access to the child process data in /proc and the PID can not be re-used until the wait(), the service-manager itself is in charge of, has happened. As a side effect, the relevant parent PID information does not get lost by a double-fork, which results in a more elaborate process tree and 'ps' output: before: # ps afx 253 ? Ss 0:00 /bin/dbus-daemon --system --nofork 294 ? Sl 0:00 /usr/libexec/polkit-1/polkitd 328 ? S 0:00 /usr/sbin/modem-manager 608 ? Sl 0:00 /usr/libexec/colord 658 ? Sl 0:00 /usr/libexec/upowerd 819 ? Sl 0:00 /usr/libexec/imsettings-daemon 916 ? Sl 0:00 /usr/libexec/udisks-daemon 917 ? S 0:00 \_ udisks-daemon: not polling any devices after: # ps afx 294 ? Ss 0:00 /bin/dbus-daemon --system --nofork 426 ? Sl 0:00 \_ /usr/libexec/polkit-1/polkitd 449 ? S 0:00 \_ /usr/sbin/modem-manager 635 ? Sl 0:00 \_ /usr/libexec/colord 705 ? Sl 0:00 \_ /usr/libexec/upowerd 959 ? Sl 0:00 \_ /usr/libexec/udisks-daemon 960 ? S 0:00 | \_ udisks-daemon: not polling any devices 977 ? Sl 0:00 \_ /usr/libexec/packagekitd This prctl is orthogonal to PID namespaces. PID namespaces are isolated from each other, while a service management process usually requires the services to live in the same namespace, to be able to talk to each other. Users of this will be the systemd per-user instance, which provides init-like functionality for the user's login session and D-Bus, which activates bus services on-demand. Both need init-like capabilities to be able to properly keep track of the services they start. Many thanks to Oleg for several rounds of review and insights. [akpm@linux-foundation.org: fix comment layout and spelling] [akpm@linux-foundation.org: add lengthy code comment from Oleg] Reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Lennart Poettering <lennart@poettering.net> Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Acked-by: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-15prctl: use CAP_SYS_RESOURCE for PR_SET_MM optionCyrill Gorcunov
CAP_SYS_ADMIN is already overloaded left and right, so to have more fine-grained access control use CAP_SYS_RESOURCE here. The CAP_SYS_RESOUCE is chosen because this prctl option allows a current process to adjust some fields of memory map descriptor which rather represents what the process owns: pointers to code, data, stack segments, command line, auxiliary vector data and etc. Suggested-by: Michael Kerrisk <mtk.manpages@gmail.com> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul Bolle <pebolle@tiscali.nl> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-12c/r: prctl: add PR_SET_MM codes to set up mm_struct entriesCyrill Gorcunov
When we restore a task we need to set up text, data and data heap sizes from userspace to the values a task had at checkpoint time. This patch adds auxilary prctl codes for that. While most of them have a statistical nature (their values are involved into calculation of /proc/<pid>/statm output) the start_brk and brk values are used to compute an allowed size of program data segment expansion. Which means an arbitrary changes of this values might be dangerous operation. So to restrict access the following requirements applied to prctl calls: - The process has to have CAP_SYS_ADMIN capability granted. - For all opcodes except start_brk/brk members an appropriate VMA area must exist and should fit certain VMA flags, such as: - code segment must be executable but not writable; - data segment must not be executable. start_brk/brk values must not intersect with data segment and must not exceed RLIMIT_DATA resource limit. Still the main guard is CAP_SYS_ADMIN capability check. Note the kernel should be compiled with CONFIG_CHECKPOINT_RESTORE support otherwise these prctl calls will return -EINVAL. [akpm@linux-foundation.org: cache current->mm in a local, saving 200 bytes text] Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Tejun Heo <tj@kernel.org> Cc: Andrew Vagin <avagin@openvz.org> Cc: Serge Hallyn <serge.hallyn@canonical.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Vasiliy Kulikov <segoon@openwall.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-12-15[S390] cputime: add sparse checking and cleanupMartin Schwidefsky
Make cputime_t and cputime64_t nocast to enable sparse checking to detect incorrect use of cputime. Drop the cputime macros for simple scalar operations. The conversion macros are still needed. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-11-06Merge branch 'modsplit-Oct31_2011' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux * 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits) Revert "tracing: Include module.h in define_trace.h" irq: don't put module.h into irq.h for tracking irqgen modules. bluetooth: macroize two small inlines to avoid module.h ip_vs.h: fix implicit use of module_get/module_put from module.h nf_conntrack.h: fix up fallout from implicit moduleparam.h presence include: replace linux/module.h with "struct module" wherever possible include: convert various register fcns to macros to avoid include chaining crypto.h: remove unused crypto_tfm_alg_modname() inline uwb.h: fix implicit use of asm/page.h for PAGE_SIZE pm_runtime.h: explicitly requires notifier.h linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h miscdevice.h: fix up implicit use of lists and types stop_machine.h: fix implicit use of smp.h for smp_processor_id of: fix implicit use of errno.h in include/linux/of.h of_platform.h: delete needless include <linux/module.h> acpi: remove module.h include from platform/aclinux.h miscdevice.h: delete unnecessary inclusion of module.h device_cgroup.h: delete needless include <linux/module.h> net: sch_generic remove redundant use of <linux/module.h> net: inet_timewait_sock doesnt need <linux/module.h> ... Fix up trivial conflicts (other header files, and removal of the ab3550 mfd driver) in - drivers/media/dvb/frontends/dibx000_common.c - drivers/media/video/{mt9m111.c,ov6650.c} - drivers/mfd/ab3550-core.c - include/linux/dmaengine.h
2011-11-02sysctl: add support for poll()Lucas De Marchi
Adding support for poll() in sysctl fs allows userspace to receive notifications of changes in sysctl entries. This adds a infrastructure to allow files in sysctl fs to be pollable and implements it for hostname and domainname. [akpm@linux-foundation.org: s/declare/define/ for definitions] Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi> Cc: Greg KH <gregkh@suse.de> Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31kernel: fix several implicit usasges of kmod.hPaul Gortmaker
These files were implicitly relying on <linux/kmod.h> coming in via module.h, as without it we get things like: kernel/power/suspend.c:100: error: implicit declaration of function ‘usermodehelper_disable’ kernel/power/suspend.c:109: error: implicit declaration of function ‘usermodehelper_enable’ kernel/power/user.c:254: error: implicit declaration of function ‘usermodehelper_disable’ kernel/power/user.c:261: error: implicit declaration of function ‘usermodehelper_enable’ kernel/sys.c:317: error: implicit declaration of function ‘usermodehelper_disable’ kernel/sys.c:1816: error: implicit declaration of function ‘call_usermodehelper_setup’ kernel/sys.c:1822: error: implicit declaration of function ‘call_usermodehelper_setfns’ kernel/sys.c:1824: error: implicit declaration of function ‘call_usermodehelper_exec’ Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31kernel: Map most files to use export.h instead of module.hPaul Gortmaker
The changed files were only including linux/module.h for the EXPORT_SYMBOL infrastructure, and nothing else. Revector them onto the isolated export header for faster compile times. Nothing to see here but a whole lot of instances of: -#include <linux/module.h> +#include <linux/export.h> This commit is only changing the kernel dir; next targets will probably be mm, fs, the arch dirs, etc. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-24Merge branch 'master' of ra.kernel.org:/pub/scm/linux/kernel/git/davem/netDavid S. Miller
2011-10-17Avoid using variable-length arrays in kernel/sys.cLinus Torvalds
The size is always valid, but variable-length arrays generate worse code for no good reason (unless the function happens to be inlined and the compiler sees the length for the simple constant it is). Also, there seems to be some code generation problem on POWER, where Henrik Bakken reports that register r28 can get corrupted under some subtle circumstances (interrupt happening at the wrong time?). That all indicates some seriously broken compiler issues, but since variable length arrays are bad regardless, there's little point in trying to chase it down. "Just don't do that, then". Reported-by: Henrik Grindal Bakken <henribak@cisco.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-09-28connector: add comm change event report to proc connectorVladimir Zapolskiy
Add an event to monitor comm value changes of tasks. Such an event becomes vital, if someone desires to control threads of a process in different manner. A natural characteristic of threads is its comm value, and helpfully application developers have an opportunity to change it in runtime. Reporting about such events via proc connector allows to fine-grain monitoring and control potentials, for instance a process control daemon listening to proc connector and following comm value policies can place specific threads to assigned cgroup partitions. It might be possible to achieve a pale partial one-shot likeness without this update, if an application changes comm value of a thread generator task beforehand, then a new thread is cloned, and after that proc connector listener gets the fork event and reads new thread's comm value from procfs stat file, but this change visibly simplifies and extends the matter. Signed-off-by: Vladimir Zapolskiy <vzapolskiy@gmail.com> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Cc: David Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-08-25Add a personality to report 2.6.x version numbersAndi Kleen
I ran into a couple of programs which broke with the new Linux 3.0 version. Some of those were binary only. I tried to use LD_PRELOAD to work around it, but it was quite difficult and in one case impossible because of a mix of 32bit and 64bit executables. For example, all kind of management software from HP doesnt work, unless we pretend to run a 2.6 kernel. $ uname -a Linux svivoipvnx001 3.0.0-08107-g97cd98f #1062 SMP Fri Aug 12 18:11:45 CEST 2011 i686 i686 i386 GNU/Linux $ hpacucli ctrl all show Error: No controllers detected. $ rpm -qf /usr/sbin/hpacucli hpacucli-8.75-12.0 Another notable case is that Python now reports "linux3" from sys.platform(); which in turn can break things that were checking sys.platform() == "linux2": https://bugzilla.mozilla.org/show_bug.cgi?id=664564 It seems pretty clear to me though it's a bug in the apps that are using '==' instead of .startswith(), but this allows us to unbreak broken programs. This patch adds a UNAME26 personality that makes the kernel report a 2.6.40+x version number instead. The x is the x in 3.x. I know this is somewhat ugly, but I didn't find a better workaround, and compatibility to existing programs is important. Some programs also read /proc/sys/kernel/osrelease. This can be worked around in user space with mount --bind (and a mount namespace) To use: wget ftp://ftp.kernel.org/pub/linux/kernel/people/ak/uname26/uname26.c gcc -o uname26 uname26.c ./uname26 program Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-08-11move RLIMIT_NPROC check from set_user() to do_execve_common()Vasiliy Kulikov
The patch http://lkml.org/lkml/2003/7/13/226 introduced an RLIMIT_NPROC check in set_user() to check for NPROC exceeding via setuid() and similar functions. Before the check there was a possibility to greatly exceed the allowed number of processes by an unprivileged user if the program relied on rlimit only. But the check created new security threat: many poorly written programs simply don't check setuid() return code and believe it cannot fail if executed with root privileges. So, the check is removed in this patch because of too often privilege escalations related to buggy programs. The NPROC can still be enforced in the common code flow of daemons spawning user processes. Most of daemons do fork()+setuid()+execve(). The check introduced in execve() (1) enforces the same limit as in setuid() and (2) doesn't create similar security issues. Neil Brown suggested to track what specific process has exceeded the limit by setting PF_NPROC_EXCEEDED process flag. With the change only this process would fail on execve(), and other processes' execve() behaviour is not changed. Solar Designer suggested to re-check whether NPROC limit is still exceeded at the moment of execve(). If the process was sleeping for days between set*uid() and execve(), and the NPROC counter step down under the limit, the defered execve() failure because NPROC limit was exceeded days ago would be unexpected. If the limit is not exceeded anymore, we clear the flag on successful calls to execve() and fork(). The flag is also cleared on successful calls to set_user() as the limit was exceeded for the previous user, not the current one. Similar check was introduced in -ow patches (without the process flag). v3 - clear PF_NPROC_EXCEEDED on successful calls to set_user(). Reviewed-by: James Morris <jmorris@namei.org> Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Acked-by: NeilBrown <neilb@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-25notifiers: sys: move reboot notifiers into reboot.hAmerigo Wang
It is not necessary to share the same notifier.h. This patch already moves register_reboot_notifier() and unregister_reboot_notifier() from kernel/notifier.c to kernel/sys.c. [amwang@redhat.com: make allyesconfig succeed on ppc64] Signed-off-by: WANG Cong <amwang@redhat.com> Cc: David Miller <davem@davemloft.net> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Greg KH <greg@kroah.com> Signed-off-by: WANG Cong <amwang@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-19Merge branch 'driver-core-next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6 * 'driver-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6: (44 commits) debugfs: Silence DEBUG_STRICT_USER_COPY_CHECKS=y warning sysfs: remove "last sysfs file:" line from the oops messages drivers/base/memory.c: fix warning due to "memory hotplug: Speed up add/remove when blocks are larger than PAGES_PER_SECTION" memory hotplug: Speed up add/remove when blocks are larger than PAGES_PER_SECTION SYSFS: Fix erroneous comments for sysfs_update_group(). driver core: remove the driver-model structures from the documentation driver core: Add the device driver-model structures to kerneldoc Translated Documentation/email-clients.txt RAW driver: Remove call to kobject_put(). reboot: disable usermodehelper to prevent fs access efivars: prevent oops on unload when efi is not enabled Allow setting of number of raw devices as a module parameter Introduce CONFIG_GOOGLE_FIRMWARE driver: Google Memory Console driver: Google EFI SMI x86: Better comments for get_bios_ebda() x86: get_bios_ebda_length() misc: fix ti-st build issues params.c: Use new strtobool function to process boolean inputs debugfs: move to new strtobool ... Fix up trivial conflicts in fs/debugfs/file.c due to the same patch being applied twice, and an unrelated cleanup nearby.
2011-05-11PM: Remove sysdev suspend, resume and shutdown operationsRafael J. Wysocki
Since suspend, resume and shutdown operations in struct sysdev_class and struct sysdev_driver are not used any more, remove them. Also drop sysdev_suspend(), sysdev_resume() and sysdev_shutdown() used for executing those operations and modify all of their users accordingly. This reduces kernel code size quite a bit and reduces its complexity. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-05-06reboot: disable usermodehelper to prevent fs accessKay Sievers
In case CONFIG_UEVENT_HELPER_PATH is not set to "", which it should be on every system, the kernel forks processes during shutdown, which try to access the rootfs, even when the binary does not exist. It causes exceptions and long delays in the disk driver, which gets read requests at the time it tries to shut down the disk. This patch disables all kernel-forked processes during reboot to allow a clean poweroff. Cc: Tejun Heo <htejun@gmail.com> Tested-By: Anton Guda <atu@dmeti.dp.ua> Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-03-23userns: user namespaces: convert all capable checks in kernel/sys.cSerge E. Hallyn
This allows setuid/setgid in containers. It also fixes some corner cases where kernel logic foregoes capability checks when uids are equivalent. The latter will need to be done throughout the whole kernel. Changelog: Jan 11: Use nsown_capable() as suggested by Bastian Blank. Jan 11: Fix logic errors in uid checks pointed out by Bastian. Feb 15: allow prlimit to current (was regression in previous version) Feb 23: remove debugging printks, uninline set_one_prio_perm and make it bool, and document its return value. Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Daniel Lezcano <daniel.lezcano@free.fr> Acked-by: David Howells <dhowells@redhat.com> Cc: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23userns: allow sethostname in a containerSerge E. Hallyn
Changelog: Feb 23: let clone_uts_ns() handle setting uts->user_ns To do so we need to pass in the task_struct who'll get the utsname, so we can get its user_ns. Feb 23: As per Oleg's coment, just pass in tsk, instead of two of its members. Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Daniel Lezcano <daniel.lezcano@free.fr> Acked-by: David Howells <dhowells@redhat.com> Cc: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-15PM / Core: Introduce struct syscore_ops for core subsystems PMRafael J. Wysocki
Some subsystems need to carry out suspend/resume and shutdown operations with one CPU on-line and interrupts disabled. The only way to register such operations is to define a sysdev class and a sysdev specifically for this purpose which is cumbersome and inefficient. Moreover, the arguments taken by sysdev suspend, resume and shutdown callbacks are practically never necessary. For this reason, introduce a simpler interface allowing subsystems to register operations to be executed very late during system suspend and shutdown and very early during resume in the form of strcut syscore_ops objects. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-01-31Fix prlimit64 for suid/sgid processesKacper Kornet
Since check_prlimit_permission always fails in the case of SUID/GUID processes, such processes are not able to read or set their own limits. This commit changes this by assuming that process can always read/change its own limits. Signed-off-by: Kacper Kornet <kornet@camk.edu.pl> Acked-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13kmsg_dump: add kmsg_dump() calls to the reboot, halt, poweroff and ↵Seiji Aguchi
emergency_restart paths We need to know the reason why system rebooted in support service. However, we can't inform our customers of the reason because final messages are lost on current Linux kernel. This patch improves the situation above because the final messages are saved by adding kmsg_dump() to reboot, halt, poweroff and emergency_restart path. Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Marco Stornelli <marco.stornelli@gmail.com> Reviewed-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-30sched: Add 'autogroup' scheduling feature: automated per session task groupsMike Galbraith
A recurring complaint from CFS users is that parallel kbuild has a negative impact on desktop interactivity. This patch implements an idea from Linus, to automatically create task groups. Currently, only per session autogroups are implemented, but the patch leaves the way open for enhancement. Implementation: each task's signal struct contains an inherited pointer to a refcounted autogroup struct containing a task group pointer, the default for all tasks pointing to the init_task_group. When a task calls setsid(), a new task group is created, the process is moved into the new task group, and a reference to the preveious task group is dropped. Child processes inherit this task group thereafter, and increase it's refcount. When the last thread of a process exits, the process's reference is dropped, such that when the last process referencing an autogroup exits, the autogroup is destroyed. At runqueue selection time, IFF a task has no cgroup assignment, its current autogroup is used. Autogroup bandwidth is controllable via setting it's nice level through the proc filesystem: cat /proc/<pid>/autogroup Displays the task's group and the group's nice level. echo <nice level> > /proc/<pid>/autogroup Sets the task group's shares to the weight of nice <level> task. Setting nice level is rate limited for !admin users due to the abuse risk of task group locking. The feature is enabled from boot by default if CONFIG_SCHED_AUTOGROUP=y is selected, but can be disabled via the boot option noautogroup, and can also be turned on/off on the fly via: echo [01] > /proc/sys/kernel/sched_autogroup_enabled ... which will automatically move tasks to/from the root task group. Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Markus Trippelsdorf <markus@trippelsdorf.de> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Paul Turner <pjt@google.com> Cc: Oleg Nesterov <oleg@redhat.com> [ Removed the task_group_path() debug code, and fixed !EVENTFD build failure. ] Signed-off-by: Ingo Molnar <mingo@elte.hu> LKML-Reference: <1290281700.28711.9.camel@maggy.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-08-31pid: make setpgid() system call use RCU read-side critical sectionPaul E. McKenney
[ 23.584719] [ 23.584720] =================================================== [ 23.585059] [ INFO: suspicious rcu_dereference_check() usage. ] [ 23.585176] --------------------------------------------------- [ 23.585176] kernel/pid.c:419 invoked rcu_dereference_check() without protection! [ 23.585176] [ 23.585176] other info that might help us debug this: [ 23.585176] [ 23.585176] [ 23.585176] rcu_scheduler_active = 1, debug_locks = 1 [ 23.585176] 1 lock held by rc.sysinit/728: [ 23.585176] #0: (tasklist_lock){.+.+..}, at: [<ffffffff8104771f>] sys_setpgid+0x5f/0x193 [ 23.585176] [ 23.585176] stack backtrace: [ 23.585176] Pid: 728, comm: rc.sysinit Not tainted 2.6.36-rc2 #2 [ 23.585176] Call Trace: [ 23.585176] [<ffffffff8105b436>] lockdep_rcu_dereference+0x99/0xa2 [ 23.585176] [<ffffffff8104c324>] find_task_by_pid_ns+0x50/0x6a [ 23.585176] [<ffffffff8104c35b>] find_task_by_vpid+0x1d/0x1f [ 23.585176] [<ffffffff81047727>] sys_setpgid+0x67/0x193 [ 23.585176] [<ffffffff810029eb>] system_call_fastpath+0x16/0x1b [ 24.959669] type=1400 audit(1282938522.956:4): avc: denied { module_request } for pid=766 comm="hwclock" kmod="char-major-10-135" scontext=system_u:system_r:hwclock_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclas It turns out that the setpgid() system call fails to enter an RCU read-side critical section before doing a PID-to-task_struct translation. This commit therefore does rcu_read_lock() before the translation, and also does rcu_read_unlock() after the last use of the returned pointer. Reported-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: David Howells <dhowells@redhat.com>
2010-07-16rlimits: implement prlimit64 syscallJiri Slaby
This patch adds the code to support the sys_prlimit64 syscall which modifies-and-returns the rlim values of a selected process atomically. The first parameter, pid, being 0 means current process. Unlike the current implementation, it is a generic interface, architecture indepentent so that we needn't handle compat stuff anymore. In the future, after glibc start to use this we can deprecate sys_setrlimit and sys_getrlimit in favor to clean up the code finally. It also adds a possibility of changing limits of other processes. We check the user's permissions to do that and if it succeeds, the new limits are propagated online. This is good for large scale applications such as SAP or databases where administrators need to change limits time by time (e.g. on crashes increase core size). And it is unacceptable to restart the service. For safety, all rlim users now either use accessors or doesn't need them due to - locking - the fact a process was just forked and nobody else knows about it yet (and nobody can't thus read/write limits) hence it is safe to modify limits now. The limitation is that we currently stay at ulong internal representation. So the rlim64_is_infinity check is used where value is compared against ULONG_MAX on 32-bit which is the maximum value there. And since internally the limits are held in struct rlimit, converters which are used before and after do_prlimit call in sys_prlimit64 are introduced. Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2010-07-16rlimits: switch more rlimit syscalls to do_prlimitJiri Slaby
After we added more generic do_prlimit, switch sys_getrlimit to that. Also switch compat handling, so we can get rid of ugly __user casts and avoid setting process' address limit to kernel data and back. Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2010-07-16rlimits: redo do_setrlimit to more generic do_prlimitJiri Slaby
It now allows also reading of limits. I.e. all read and writes will later use this function. It takes two parameters, new and old limits which can be both NULL. If new is non-NULL, the value in it is set to rlimits. If old is non-NULL, current rlimits are stored there. If both are non-NULL, old are stored prior to setting the new ones, atomically. (Similar to sigaction.) Signed-off-by: Jiri Slaby <jslaby@suse.cz>