- 14 Aug, 2008 1 commit
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David Howells authored
Fix the setting of PF_SUPERPRIV by __capable() as it could corrupt the flags the target process if that is not the current process and it is trying to change its own flags in a different way at the same time. __capable() is using neither atomic ops nor locking to protect t->flags. This patch removes __capable() and introduces has_capability() that doesn't set PF_SUPERPRIV on the process being queried. This patch further splits security_ptrace() in two: (1) security_ptrace_may_access(). This passes judgement on whether one process may access another only (PTRACE_MODE_ATTACH for ptrace() and PTRACE_MODE_READ for /proc), and takes a pointer to the child process. current is the parent. (2) security_ptrace_traceme(). This passes judgement on PTRACE_TRACEME only, and takes only a pointer to the parent process. current is the child. In Smack and commoncap, this uses has_capability() to determine whether the parent will be permitted to use PTRACE_ATTACH if normal checks fail. This does not set PF_SUPERPRIV. Two of the instances of __capable() actually only act on current, and so have been changed to calls to capable(). Of the places that were using __capable(): (1) The OOM killer calls __capable() thrice when weighing the killability of a process. All of these now use has_capability(). (2) cap_ptrace() and smack_ptrace() were using __capable() to check to see whether the parent was allowed to trace any process. As mentioned above, these have been split. For PTRACE_ATTACH and /proc, capable() is now used, and for PTRACE_TRACEME, has_capability() is used. (3) cap_safe_nice() only ever saw current, so now uses capable(). (4) smack_setprocattr() rejected accesses to tasks other than current just after calling __capable(), so the order of these two tests have been switched and capable() is used instead. (5) In smack_file_send_sigiotask(), we need to allow privileged processes to receive SIGIO on files they're manipulating. (6) In smack_task_wait(), we let a process wait for a privileged process, whether or not the process doing the waiting is privileged. I've tested this with the LTP SELinux and syscalls testscripts. Signed-off-by:David Howells <dhowells@redhat.com> Acked-by:
Serge Hallyn <serue@us.ibm.com> Acked-by:
Casey Schaufler <casey@schaufler-ca.com> Acked-by:
Andrew G. Morgan <morgan@kernel.org> Acked-by:
Al Viro <viro@zeniv.linux.org.uk> Signed-off-by:
James Morris <jmorris@namei.org>
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- 24 Jul, 2008 1 commit
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Andrew G. Morgan authored
To date, we've tried hard to confine filesystem support for capabilities to the security modules. This has left a lot of the code in kernel/capability.c in a state where it looks like it supports something that filesystem support for capabilities actually suppresses when the LSM security/commmoncap.c code runs. What is left is a lot of code that uses sub-optimal locking in the main kernel With this change we refactor the main kernel code and make it explicit which locks are needed and that the only remaining kernel races in this area are associated with non-filesystem capability code. Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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- 04 Jul, 2008 1 commit
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Andrew G. Morgan authored
This commit includes a bugfix for the fragile setuid fixup code in the case that filesystem capabilities are supported (in access()). The effect of this fix is gated on filesystem capability support because changing securebits is only supported when filesystem capabilities support is configured.) [akpm@linux-foundation.org: coding-style fixes] Signed-off-by:
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- 31 May, 2008 1 commit
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Andrew G. Morgan authored
Source code out there hard-codes a notion of what the _LINUX_CAPABILITY_VERSION #define means in terms of the semantics of the raw capability system calls capget() and capset(). Its unfortunate, but true. Since the confusing header file has been in a released kernel, there is software that is erroneously using 64-bit capabilities with the semantics of 32-bit compatibilities. These recently compiled programs may suffer corruption of their memory when sys_getcap() overwrites more memory than they are coded to expect, and the raising of added capabilities when using sys_capset(). As such, this patch does a number of things to clean up the situation for all. It 1. forces the _LINUX_CAPABILITY_VERSION define to always retain its legacy value. 2. adopts a new #define strategy for the kernel's internal implementation of the preferred magic. 3. deprecates v2 capability magic in favor of a new (v3) magic number. The functionality of v3 is entirely equivalent to v2, the only difference being that the v2 magic causes the kernel to log a "deprecated" warning so the admin can find applications that may be using v2 inappropriately. [User space code continues to be encouraged to use the libcap API which protects the application from details like this. libcap-2.10 is the first to support v3 capabilities.] Fixes issue reported in https://bugzilla.redhat.com/show_bug.cgi?id=447518 . Thanks to Bojan Smojver for the report. [akpm@linux-foundation.org: s/depreciate/deprecate/g] [akpm@linux-foundation.org: be robust about put_user size] [akpm@linux-foundation.org: coding-style fixes] Signed-off-by:Chris Wright <chrisw@sous-sol.org>
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- 05 Feb, 2008 1 commit
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Andrew Morgan authored
The patch supports legacy (32-bit) capability userspace, and where possible translates 32-bit capabilities to/from userspace and the VFS to 64-bit kernel space capabilities. If a capability set cannot be compressed into 32-bits for consumption by user space, the system call fails, with -ERANGE. FWIW libcap-2.00 supports this change (and earlier capability formats) http://www.kernel.org/pub/linux/libs/security/linux-privs/kernel-2.6/ [akpm@linux-foundation.org: coding-syle fixes] [akpm@linux-foundation.org: use get_task_comm()] [ezk@cs.sunysb.edu: build fix] [akpm@linux-foundation.org: do not initialise statics to 0 or NULL] [akpm@linux-foundation.org: unused var] [serue@us.ibm.com: export __cap_ symbols] Signed-off-by:
Erez Zadok <ezk@cs.sunysb.edu> Signed-off-by:
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- 19 Oct, 2007 4 commits
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Pavel Emelyanov authored
The find_pid/_vpid/_pid_ns functions are used to find the struct pid by its id, depending on whic id - global or virtual - is used. The find_vpid() is a macro that pushes the current->nsproxy->pid_ns on the stack to call another function - find_pid_ns(). It turned out, that this dereference together with the push itself cause the kernel text size to grow too much. Move all these out-of-line. Together with the previous patch this saves a bit less that 400 bytes from .text section. Signed-off-by:
Pavel Emelyanov <xemul@openvz.org> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Paul Menage <menage@google.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by:
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Pavel Emelyanov authored
The find_task_by_something is a set of macros are used to find task by pid depending on what kind of pid is proposed - global or virtual one. All of them are wrappers above the most generic one - find_task_by_pid_type_ns() - and just substitute some args for it. It turned out, that dereferencing the current->nsproxy->pid_ns construction and pushing one more argument on the stack inline cause kernel text size to grow. This patch moves all this stuff out-of-line into kernel/pid.c. Together with the next patch it saves a bit less than 400 bytes from the .text section. Signed-off-by:
Ingo Molnar <mingo@elte.hu> Signed-off-by:
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Pavel Emelyanov authored
This is the largest patch in the set. Make all (I hope) the places where the pid is shown to or get from user operate on the virtual pids. The idea is: - all in-kernel data structures must store either struct pid itself or the pid's global nr, obtained with pid_nr() call; - when seeking the task from kernel code with the stored id one should use find_task_by_pid() call that works with global pids; - when showing pid's numerical value to the user the virtual one should be used, but however when one shows task's pid outside this task's namespace the global one is to be used; - when getting the pid from userspace one need to consider this as the virtual one and use appropriate task/pid-searching functions. [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: nuther build fix] [akpm@linux-foundation.org: yet nuther build fix] [akpm@linux-foundation.org: remove unneeded casts] Signed-off-by: Pavel Emelyanov <xemul@openvz.org...
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Serge E. Hallyn authored
is_init() is an ambiguous name for the pid==1 check. Split it into is_global_init() and is_container_init(). A cgroup init has it's tsk->pid == 1. A global init also has it's tsk->pid == 1 and it's active pid namespace is the init_pid_ns. But rather than check the active pid namespace, compare the task structure with 'init_pid_ns.child_reaper', which is initialized during boot to the /sbin/init process and never changes. Changelog: 2.6.22-rc4-mm2-pidns1: - Use 'init_pid_ns.child_reaper' to determine if a given task is the global init (/sbin/init) process. This would improve performance and remove dependence on the task_pid(). 2.6.21-mm2-pidns2: - [Sukadev Bhattiprolu] Changed is_container_init() calls in {powerpc, ppc,avr32}/traps.c for the _exception() call to is_global_init(). This way, we kill only the cgroup if the cgroup's init has a bug rather than force a kernel panic. [akpm@linux-foundation.org: fix comment] [sukadev@us.ibm.com: Use is_global_init() in arch/m32r/mm/fault.c] [bunk@stusta.de: kernel/pid.c: remove unused exports] [sukadev@us.ibm.com: Fix capability.c to work with threaded init] Signed-off-by:Sukadev Bhattiprolu <sukadev@us.ibm.com> Acked-by:
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- 18 Oct, 2007 2 commits
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Daniel Walker authored
Large chunks of 5 spaces instead of tabs. Signed-off-by:
Daniel Walker <dwalker@mvista.com> Cc: Chris Wright <chrisw@sous-sol.org> Signed-off-by:
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Andrew Morgan authored
The non-filesystem capability meaning of CAP_SETPCAP is that a process, p1, can change the capabilities of another process, p2. This is not the meaning that was intended for this capability at all, and this implementation came about purely because, without filesystem capabilities, there was no way to use capabilities without one process bestowing them on another. Since we now have a filesystem support for capabilities we can fix the implementation of CAP_SETPCAP. The most significant thing about this change is that, with it in effect, no process can set the capabilities of another process. The capabilities of a program are set via the capability convolution rules: pI(post-exec) = pI(pre-exec) pP(post-exec) = (X(aka cap_bset) & fP) | (pI(post-exec) & fI) pE(post-exec) = fE ? pP(post-exec) : 0 at exec() time. As such, the only influence the pre-exec() program can have on the post-exec() program's capabilities are through the pI capability set. The correct implementation for CAP_SETPCAP (and that enabled by this patch) is that it can be used to add extra pI capabilities to the current process - to be picked up by subsequent exec()s when the above convolution rules are applied. Here is how it works: Let's say we have a process, p. It has capability sets, pE, pP and pI. Generally, p, can change the value of its own pI to pI' where (pI' & ~pI) & ~pP = 0. That is, the only new things in pI' that were not present in pI need to be present in pP. The role of CAP_SETPCAP is basically to permit changes to pI beyond the above: if (pE & CAP_SETPCAP) { pI' = anything; /* ie., even (pI' & ~pI) & ~pP != 0 */ } This capability is useful for things like login, which (say, via pam_cap) might want to raise certain inheritable capabilities for use by the children of the logged-in user's shell, but those capabilities are not useful to or needed by the login program itself. One such use might be to limit who can run ping. You set the capabilities of the 'ping' program to be "= cap_net_raw+i", and then only shells that have (pI & CAP_NET_RAW) will be able to run it. Without CAP_SETPCAP implemented as described above, login(pam_cap) would have to also have (pP & CAP_NET_RAW) in order to raise this capability and pass it on through the inheritable set. Signed-off-by:
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- 17 Oct, 2007 1 commit
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Adrian Bunk authored
This patch contains the following cleanups that are now possible: - remove the unused security_operations->inode_xattr_getsuffix - remove the no longer used security_operations->unregister_security - remove some no longer required exit code - remove a bunch of no longer used exports Signed-off-by:
Adrian Bunk <bunk@kernel.org> Acked-by:
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- 12 Feb, 2007 1 commit
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Eric W. Biederman authored
There isn't any real advantage to this change except that it allows the old functions to be removed. Which is easier on maintenance and puts the code in a more uniform style. Signed-off-by:
Eric W. Biederman <ebiederm@xmission.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by:
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- 29 Sep, 2006 1 commit
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Sukadev Bhattiprolu authored
This is an updated version of Eric Biederman's is_init() patch. (http://lkml.org/lkml/2006/2/6/280 ). It applies cleanly to 2.6.18-rc3 and replaces a few more instances of ->pid == 1 with is_init(). Further, is_init() checks pid and thus removes dependency on Eric's other patches for now. Eric's original description: There are a lot of places in the kernel where we test for init because we give it special properties. Most significantly init must not die. This results in code all over the kernel test ->pid == 1. Introduce is_init to capture this case. With multiple pid spaces for all of the cases affected we are looking for only the first process on the system, not some other process that has pid == 1. Signed-off-by:
Paul Mackerras <paulus@samba.org> Signed-off-by:
Andrew Morton <akpm@osdl.org> Signed-off-by:
Linus Torvalds <torvalds@osdl.org>
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- 03 Jul, 2006 1 commit
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Ingo Molnar authored
cleanup: remove task_t and convert all the uses to struct task_struct. I introduced it for the scheduler anno and it was a mistake. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by:
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- 25 Mar, 2006 1 commit
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Chris Wright authored
Move capable() to kernel/capability.c and eliminate duplicate implementations. Add __capable() function which can be used to check for capabiilty of any process. Signed-off-by:
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- 11 Jan, 2006 1 commit
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Randy.Dunlap authored
- Move capable() from sched.h to capability.h; - Use <linux/capability.h> where capable() is used (in include/, block/, ipc/, kernel/, a few drivers/, mm/, security/, & sound/; many more drivers/ to go) Signed-off-by:
Randy Dunlap <rdunlap@xenotime.net> Signed-off-by:
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- 27 Jul, 2005 1 commit
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Randy Dunlap authored
Add kerneldoc to kernel/capability.c Signed-off-by:
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- 16 Apr, 2005 1 commit
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Linus Torvalds authored
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
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