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* execve: use 'struct filename *' for executable name passingLinus Torvalds2014-02-051-24/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This changes 'do_execve()' to get the executable name as a 'struct filename', and to free it when it is done. This is what the normal users want, and it simplifies and streamlines their error handling. The controlled lifetime of the executable name also fixes a use-after-free problem with the trace_sched_process_exec tracepoint: the lifetime of the passed-in string for kernel users was not at all obvious, and the user-mode helper code used UMH_WAIT_EXEC to serialize the pathname allocation lifetime with the execve() having finished, which in turn meant that the trace point that happened after mm_release() of the old process VM ended up using already free'd memory. To solve the kernel string lifetime issue, this simply introduces "getname_kernel()" that works like the normal user-space getname() function, except with the source coming from kernel memory. As Oleg points out, this also means that we could drop the tcomm[] array from 'struct linux_binprm', since the pathname lifetime now covers setup_new_exec(). That would be a separate cleanup. Reported-by: Igor Zhbanov <i.zhbanov@samsung.com> Tested-by: Steven Rostedt <rostedt@goodmis.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs/exec.c: call arch_pick_mmap_layout() only onceRichard Weinberger2014-01-231-1/+0
| | | | | | | | | | | | | | Currently both setup_new_exec() and flush_old_exec() issue a call to arch_pick_mmap_layout(). As setup_new_exec() and flush_old_exec() are always called pairwise arch_pick_mmap_layout() is called twice. This patch removes one call from setup_new_exec() to have it only called once. Signed-off-by: Richard Weinberger <richard@nod.at> Tested-by: Pat Erley <pat-lkml@erley.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* exec: avoid propagating PF_NO_SETAFFINITY into userspace childZhang Yi2014-01-231-2/+2
| | | | | | | | | | | | | Userspace process doesn't want the PF_NO_SETAFFINITY, but its parent may be a kernel worker thread which has PF_NO_SETAFFINITY set, and this worker thread can do kernel_thread() to create the child. Clearing this flag in usersapce child to enable its migrating capability. Signed-off-by: Zhang Yi <zhang.yi20@zte.com.cn> Acked-by: Oleg Nesterov <oleg@redhat.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>
* exec: kill task_struct->did_execOleg Nesterov2014-01-231-1/+0
| | | | | | | | | | | | We can kill either task->did_exec or PF_FORKNOEXEC, they are mutually exclusive. The patch kills ->did_exec because it has a single user. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* exec: move the final allow_write_access/fput into free_bprm()Oleg Nesterov2014-01-231-15/+5
| | | | | | | | | | | | Both success/failure paths cleanup bprm->file, we can move this code into free_bprm() to simlify and cleanup this logic. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Al Viro <viro@zeniv.linux.org.uk> 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>
* exec:check_unsafe_exec: kill the dead -EAGAIN and clear_in_exec logicOleg Nesterov2014-01-231-21/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | fs_struct->in_exec == T means that this ->fs is used by a single process (thread group), and one of the treads does do_execve(). To avoid the mt-exec races this code has the following complications: 1. check_unsafe_exec() returns -EBUSY if ->in_exec was already set by another thread. 2. do_execve_common() records "clear_in_exec" to ensure that the error path can only clear ->in_exec if it was set by current. However, after 9b1bf12d5d51 "signals: move cred_guard_mutex from task_struct to signal_struct" we do not need these complications: 1. We can't race with our sub-thread, this is called under per-process ->cred_guard_mutex. And we can't race with another CLONE_FS task, we already checked that this fs is not shared. We can remove the dead -EAGAIN logic. 2. "out_unmark:" in do_execve_common() is either called under ->cred_guard_mutex, or after de_thread() which kills other threads, so we can't race with sub-thread which could set ->in_exec. And if ->fs is shared with another process ->in_exec should be false anyway. We can clear in_exec unconditionally. This also means that check_unsafe_exec() can be void. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* exec:check_unsafe_exec: use while_each_thread() rather than next_thread()Oleg Nesterov2014-01-231-1/+2
| | | | | | | | | | | | | | | | | | | next_thread() should be avoided, change check_unsafe_exec() to use while_each_thread(). Nobody except signal->curr_target actually needs next_thread-like code, and we need to change (fix) this interface. This particular code is fine, p == current. But in general the code like this can loop forever if p exits and next_thread(t) can't reach the unhashed thread. This also saves 32 bytes. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* coredump: make __get_dumpable/get_dumpable inline, kill fs/coredump.hOleg Nesterov2014-01-231-18/+0
| | | | | | | | | | | | | | | | | | | 1. Remove fs/coredump.h. It is not clear why do we need it, it only declares __get_dumpable(), signal.c includes it for no reason. 2. Now that get_dumpable() and __get_dumpable() are really trivial make them inline in linux/sched.h. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Alex Kelly <alex.page.kelly@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Petr Matousek <pmatouse@redhat.com> Cc: Vasily Kulikov <segoon@openwall.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* coredump: kill MMF_DUMPABLE and MMF_DUMP_SECURELYOleg Nesterov2014-01-231-15/+6
| | | | | | | | | | | | | | | | | | | Nobody actually needs MMF_DUMPABLE/MMF_DUMP_SECURELY, they are only used to enforce the encoding of SUID_DUMP_* enum in mm->flags & MMF_DUMPABLE_MASK. Now that set_dumpable() updates both bits atomically we can kill them and simply store the value "as is" in 2 lower bits. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Alex Kelly <alex.page.kelly@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Petr Matousek <pmatouse@redhat.com> Cc: Vasily Kulikov <segoon@openwall.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* coredump: set_dumpable: fix the theoretical race with itselfOleg Nesterov2014-01-231-34/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | set_dumpable() updates MMF_DUMPABLE_MASK in a non-trivial way to ensure that get_dumpable() can't observe the intermediate state, but this all can't help if multiple threads call set_dumpable() at the same time. And in theory commit_creds()->set_dumpable(SUID_DUMP_ROOT) racing with sys_prctl()->set_dumpable(SUID_DUMP_DISABLE) can result in SUID_DUMP_USER. Change this code to update both bits atomically via cmpxchg(). Note: this assumes that it is safe to mix bitops and cmpxchg. IOW, if, say, an architecture implements cmpxchg() using the locking (like arch/parisc/lib/bitops.c does), then it should use the same locks for set_bit/etc. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Alex Kelly <alex.page.kelly@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Petr Matousek <pmatouse@redhat.com> Cc: Vasily Kulikov <segoon@openwall.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge git://git.infradead.org/users/eparis/auditLinus Torvalds2013-11-211-4/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull audit updates from Eric Paris: "Nothing amazing. Formatting, small bug fixes, couple of fixes where we didn't get records due to some old VFS changes, and a change to how we collect execve info..." Fixed conflict in fs/exec.c as per Eric and linux-next. * git://git.infradead.org/users/eparis/audit: (28 commits) audit: fix type of sessionid in audit_set_loginuid() audit: call audit_bprm() only once to add AUDIT_EXECVE information audit: move audit_aux_data_execve contents into audit_context union audit: remove unused envc member of audit_aux_data_execve audit: Kill the unused struct audit_aux_data_capset audit: do not reject all AUDIT_INODE filter types audit: suppress stock memalloc failure warnings since already managed audit: log the audit_names record type audit: add child record before the create to handle case where create fails audit: use given values in tty_audit enable api audit: use nlmsg_len() to get message payload length audit: use memset instead of trying to initialize field by field audit: fix info leak in AUDIT_GET requests audit: update AUDIT_INODE filter rule to comparator function audit: audit feature to set loginuid immutable audit: audit feature to only allow unsetting the loginuid audit: allow unsetting the loginuid (with priv) audit: remove CONFIG_AUDIT_LOGINUID_IMMUTABLE audit: loginuid functions coding style selinux: apply selinux checks on new audit message types ...
| * audit: call audit_bprm() only once to add AUDIT_EXECVE informationRichard Guy Briggs2013-11-051-4/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move the audit_bprm() call from search_binary_handler() to exec_binprm(). This allows us to get rid of the mm member of struct audit_aux_data_execve since bprm->mm will equal current->mm. This also mitigates the issue that ->argc could be modified by the load_binary() call in search_binary_handler(). audit_bprm() was being called to add an AUDIT_EXECVE record to the audit context every time search_binary_handler() was recursively called. Only one reference is necessary. Reported-by: Oleg Nesterov <onestero@redhat.com> Cc: Eric Paris <eparis@redhat.com> Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Eric Paris <eparis@redhat.com> --- This patch is against 3.11, but was developed on Oleg's post-3.11 patches that introduce exec_binprm().
* | Merge branch 'akpm' (patches from Andrew Morton)Linus Torvalds2013-11-131-0/+6
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge first patch-bomb from Andrew Morton: "Quite a lot of other stuff is banked up awaiting further next->mainline merging, but this batch contains: - Lots of random misc patches - OCFS2 - Most of MM - backlight updates - lib/ updates - printk updates - checkpatch updates - epoll tweaking - rtc updates - hfs - hfsplus - documentation - procfs - update gcov to gcc-4.7 format - IPC" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (269 commits) ipc, msg: fix message length check for negative values ipc/util.c: remove unnecessary work pending test devpts: plug the memory leak in kill_sb ./Makefile: export initial ramdisk compression config option init/Kconfig: add option to disable kernel compression drivers: w1: make w1_slave::flags long to avoid memory corruption drivers/w1/masters/ds1wm.cuse dev_get_platdata() drivers/memstick/core/ms_block.c: fix unreachable state in h_msb_read_page() drivers/memstick/core/mspro_block.c: fix attributes array allocation drivers/pps/clients/pps-gpio.c: remove redundant of_match_ptr kernel/panic.c: reduce 1 byte usage for print tainted buffer gcov: reuse kbasename helper kernel/gcov/fs.c: use pr_warn() kernel/module.c: use pr_foo() gcov: compile specific gcov implementation based on gcc version gcov: add support for gcc 4.7 gcov format gcov: move gcov structs definitions to a gcc version specific file kernel/taskstats.c: return -ENOMEM when alloc memory fails in add_del_listener() kernel/taskstats.c: add nla_nest_cancel() for failure processing between nla_nest_start() and nla_nest_end() kernel/sysctl_binary.c: use scnprintf() instead of snprintf() ...
| * | exec/ptrace: fix get_dumpable() incorrect testsKees Cook2013-11-131-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The get_dumpable() return value is not boolean. Most users of the function actually want to be testing for non-SUID_DUMP_USER(1) rather than SUID_DUMP_DISABLE(0). The SUID_DUMP_ROOT(2) is also considered a protected state. Almost all places did this correctly, excepting the two places fixed in this patch. Wrong logic: if (dumpable == SUID_DUMP_DISABLE) { /* be protective */ } or if (dumpable == 0) { /* be protective */ } or if (!dumpable) { /* be protective */ } Correct logic: if (dumpable != SUID_DUMP_USER) { /* be protective */ } or if (dumpable != 1) { /* be protective */ } Without this patch, if the system had set the sysctl fs/suid_dumpable=2, a user was able to ptrace attach to processes that had dropped privileges to that user. (This may have been partially mitigated if Yama was enabled.) The macros have been moved into the file that declares get/set_dumpable(), which means things like the ia64 code can see them too. CVE-2013-2929 Reported-by: Vasily Kulikov <segoon@openwall.com> Signed-off-by: Kees Cook <keescook@chromium.org> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Merge branch 'for-linus' of ↵Linus Torvalds2013-11-131-20/+15
|\ \ \ | |/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs updates from Al Viro: "All kinds of stuff this time around; some more notable parts: - RCU'd vfsmounts handling - new primitives for coredump handling - files_lock is gone - Bruce's delegations handling series - exportfs fixes plus misc stuff all over the place" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (101 commits) ecryptfs: ->f_op is never NULL locks: break delegations on any attribute modification locks: break delegations on link locks: break delegations on rename locks: helper functions for delegation breaking locks: break delegations on unlink namei: minor vfs_unlink cleanup locks: implement delegations locks: introduce new FL_DELEG lock flag vfs: take i_mutex on renamed file vfs: rename I_MUTEX_QUOTA now that it's not used for quotas vfs: don't use PARENT/CHILD lock classes for non-directories vfs: pull ext4's double-i_mutex-locking into common code exportfs: fix quadratic behavior in filehandle lookup exportfs: better variable name exportfs: move most of reconnect_path to helper function exportfs: eliminate unused "noprogress" counter exportfs: stop retrying once we race with rename/remove exportfs: clear DISCONNECTED on all parents sooner exportfs: more detailed comment for path_reconnect ...
| * | file->f_op is never NULL...Al Viro2013-10-241-20/+15
| | | | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | | sched/numa: Call task_numa_free() from do_execve()Rik van Riel2013-10-091-0/+1
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It is possible for a task in a numa group to call exec, and have the new (unrelated) executable inherit the numa group association from its former self. This has the potential to break numa grouping, and is trivial to fix. Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1381141781-10992-51-git-send-email-mgorman@suse.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | exec: cleanup the error handling in search_binary_handler()Oleg Nesterov2013-09-111-8/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The error hanling and ret-from-loop look confusing and inconsistent. - "retval >= 0" simply returns - "!bprm->file" returns too but with read_unlock() because binfmt_lock was already re-acquired - "retval != -ENOEXEC || bprm->mm == NULL" does "break" and relies on the same check after the main loop Consolidate these checks into a single if/return statement. need_retry still checks "retval == -ENOEXEC", but this and -ENOENT before the main loop are not needed. This is only for pathological and impossible list_empty(&formats) case. It is not clear why do we check "bprm->mm == NULL", probably this should be removed. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Evgeniy Polyakov <zbr@ioremap.net> Cc: Zach Levis <zml@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | exec: don't retry if request_module() failsOleg Nesterov2013-09-111-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A separate one-liner for better documentation. It doesn't make sense to retry if request_module() fails to exec /sbin/modprobe, add the additional "request_module() < 0" check. However, this logic still doesn't look exactly right: 1. It would be better to check "request_module() != 0", the user space modprobe process should report the correct exit code. But I didn't dare to add the user-visible change. 2. The whole ENOEXEC logic looks suboptimal. Suppose that we try to exec a "#!path-to-unsupported-binary" script. In this case request_module() + "retry" will be done twice: first by the "depth == 1" code, and then again by the "depth == 0" caller which doesn't make sense. 3. And note that in the case above bprm->buf was already changed by load_script()->prepare_binprm(), so this looks even more ugly. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Evgeniy Polyakov <zbr@ioremap.net> Cc: Zach Levis <zml@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | exec: cleanup the CONFIG_MODULES logicOleg Nesterov2013-09-111-37/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | search_binary_handler() uses "for (try=0; try<2; try++)" to avoid "goto" but the code looks too complicated and horrible imho. We still need to check "try == 0" before request_module() and add the additional "break" for !CONFIG_MODULES case. Kill this loop and use a simple "bool need_retry" + "goto retry". The code looks much simpler and we do not even need ifdef's, gcc can optimize out the "if (need_retry)" block if !IS_ENABLED(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Evgeniy Polyakov <zbr@ioremap.net> Cc: Zach Levis <zml@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | exec: kill ->load_binary != NULL check in search_binary_handler()Oleg Nesterov2013-09-111-4/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | search_binary_handler() checks ->load_binary != NULL for no reason, this method should be always defined. Turn this check into WARN_ON() and move it into __register_binfmt(). Also, kill the function pointer. The current code looks confusing, as if ->load_binary can go away after read_unlock(&binfmt_lock). But we rely on module_get(fmt->module), this fmt can't be changed or unregistered, otherwise this code is buggy anyway. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Evgeniy Polyakov <zbr@ioremap.net> Cc: Zach Levis <zml@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | exec: move allow_write_access/fput to exec_binprm()Oleg Nesterov2013-09-111-4/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When search_binary_handler() succeeds it does allow_write_access() and fput(), then it clears bprm->file to ensure the caller will not do the same. We can simply move this code to exec_binprm() which is called only once. In fact we could move this to free_bprm() and remove the same code in do_execve_common's error path. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Evgeniy Polyakov <zbr@ioremap.net> Cc: Zach Levis <zml@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | exec: proc_exec_connector() should be called only onceOleg Nesterov2013-09-111-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A separate one-liner with the minor fix. PROC_EVENT_EXEC reports the "exec" event, but this message is sent at least twice if search_binary_handler() is called by ->load_binary() recursively, say, load_script(). Move it to exec_binprm(), this is "depth == 0" code too. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Evgeniy Polyakov <zbr@ioremap.net> Cc: Zach Levis <zml@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | exec: kill "int depth" in search_binary_handler()Oleg Nesterov2013-09-111-5/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Nobody except search_binary_handler() should touch ->recursion_depth, "int depth" buys nothing but complicates the code, kill it. Probably we should also kill "fn" and the !NULL check, ->load_binary should be always defined. And it can not go away after read_unlock() or this code is buggy anyway. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Evgeniy Polyakov <zbr@ioremap.net> Cc: Zach Levis <zml@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | exec: introduce exec_binprm() for "depth == 0" codeOleg Nesterov2013-09-111-14/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | task_pid_nr_ns() and trace/ptrace code in the middle of the recursive search_binary_handler() looks confusing and imho annoying. We only need this code if "depth == 0", lets add a simple helper which calls search_binary_handler() and does trace_sched_process_exec() + ptrace_event(). The patch also moves the setting of task->did_exec, we need to do this only once. Note: we can kill either task->did_exec or PF_FORKNOEXEC. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Evgeniy Polyakov <zbr@ioremap.net> Cc: Zach Levis <zml@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: track vma changes with VM_SOFTDIRTY bitCyrill Gorcunov2013-09-111-1/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pavel reported that in case if vma area get unmapped and then mapped (or expanded) in-place, the soft dirty tracker won't be able to recognize this situation since it works on pte level and ptes are get zapped on unmap, loosing soft dirty bit of course. So to resolve this situation we need to track actions on vma level, there VM_SOFTDIRTY flag comes in. When new vma area created (or old expanded) we set this bit, and keep it here until application calls for clearing soft dirty bit. Thus when user space application track memory changes now it can detect if vma area is renewed. Reported-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Matt Mackall <mpm@selenic.com> Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Rob Landley <rob@landley.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Fix TLB gather virtual address range invalidation corner casesLinus Torvalds2013-08-161-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Ben Tebulin reported: "Since v3.7.2 on two independent machines a very specific Git repository fails in 9/10 cases on git-fsck due to an SHA1/memory failures. This only occurs on a very specific repository and can be reproduced stably on two independent laptops. Git mailing list ran out of ideas and for me this looks like some very exotic kernel issue" and bisected the failure to the backport of commit 53a59fc67f97 ("mm: limit mmu_gather batching to fix soft lockups on !CONFIG_PREEMPT"). That commit itself is not actually buggy, but what it does is to make it much more likely to hit the partial TLB invalidation case, since it introduces a new case in tlb_next_batch() that previously only ever happened when running out of memory. The real bug is that the TLB gather virtual memory range setup is subtly buggered. It was introduced in commit 597e1c3580b7 ("mm/mmu_gather: enable tlb flush range in generic mmu_gather"), and the range handling was already fixed at least once in commit e6c495a96ce0 ("mm: fix the TLB range flushed when __tlb_remove_page() runs out of slots"), but that fix was not complete. The problem with the TLB gather virtual address range is that it isn't set up by the initial tlb_gather_mmu() initialization (which didn't get the TLB range information), but it is set up ad-hoc later by the functions that actually flush the TLB. And so any such case that forgot to update the TLB range entries would potentially miss TLB invalidates. Rather than try to figure out exactly which particular ad-hoc range setup was missing (I personally suspect it's the hugetlb case in zap_huge_pmd(), which didn't have the same logic as zap_pte_range() did), this patch just gets rid of the problem at the source: make the TLB range information available to tlb_gather_mmu(), and initialize it when initializing all the other tlb gather fields. This makes the patch larger, but conceptually much simpler. And the end result is much more understandable; even if you want to play games with partial ranges when invalidating the TLB contents in chunks, now the range information is always there, and anybody who doesn't want to bother with it won't introduce subtle bugs. Ben verified that this fixes his problem. Reported-bisected-and-tested-by: Ben Tebulin <tebulin@googlemail.com> Build-testing-by: Stephen Rothwell <sfr@canb.auug.org.au> Build-testing-by: Richard Weinberger <richard.weinberger@gmail.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs/exec.c:de_thread: mt-exec should update ->real_start_timeOleg Nesterov2013-07-031-0/+1
| | | | | | | | | | | | | | | | 924b42d5 ("Use boot based time for process start time and boot time in /proc") updated copy_process/do_task_stat but forgot about de_thread(). This breaks "ps axOT" if a sub-thread execs. Note: I think that task->start_time should die. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: John Stultz <johnstul@us.ibm.com> Cc: Tomas Janousek <tjanouse@redhat.com> Cc: Tomas Smetana <tsmetana@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs/exec.c: do_execve_common(): use current_user()Oleg Nesterov2013-07-031-2/+1
| | | | | | | | | | Trivial cleanup. do_execve_common() can use current_user() and avoid the unnecessary "struct cred *cred" var. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs/exec.c:de_thread(): use change_pid() rather than detach_pid/attach_pidOleg Nesterov2013-07-031-2/+1
| | | | | | | | | | | | | | de_thread() can use change_pid() instead of detach + attach. This looks better and this ensures that, say, next_thread() can never see a task with ->pid == NULL. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Sergey Dyasly <dserrg@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-linus' of ↵Linus Torvalds2013-07-031-4/+6
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull second set of VFS changes from Al Viro: "Assorted f_pos race fixes, making do_splice_direct() safe to call with i_mutex on parent, O_TMPFILE support, Jeff's locks.c series, ->d_hash/->d_compare calling conventions changes from Linus, misc stuff all over the place." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits) Document ->tmpfile() ext4: ->tmpfile() support vfs: export lseek_execute() to modules lseek_execute() doesn't need an inode passed to it block_dev: switch to fixed_size_llseek() cpqphp_sysfs: switch to fixed_size_llseek() tile-srom: switch to fixed_size_llseek() proc_powerpc: switch to fixed_size_llseek() ubi/cdev: switch to fixed_size_llseek() pci/proc: switch to fixed_size_llseek() isapnp: switch to fixed_size_llseek() lpfc: switch to fixed_size_llseek() locks: give the blocked_hash its own spinlock locks: add a new "lm_owner_key" lock operation locks: turn the blocked_list into a hashtable locks: convert fl_link to a hlist_node locks: avoid taking global lock if possible when waking up blocked waiters locks: protect most of the file_lock handling with i_lock locks: encapsulate the fl_link list handling locks: make "added" in __posix_lock_file a bool ...
| * allow build_open_flags() to return an errorAl Viro2013-06-291-4/+6
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | perf: Disable monitoring on setuid processes for regular usersStephane Eranian2013-06-261-7/+9
|/ | | | | | | | | | | | | | | | | | There was a a bug in setup_new_exec(), whereby the test to disabled perf monitoring was not correct because the new credentials for the process were not yet committed and therefore the get_dumpable() test was never firing. The patch fixes the problem by moving the perf_event test until after the credentials are committed. Signed-off-by: Stephane Eranian <eranian@google.com> Tested-by: Jiri Olsa <jolsa@redhat.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: <stable@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Merge branch 'for-linus' of ↵Linus Torvalds2013-05-011-0/+9
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull VFS updates from Al Viro, Misc cleanups all over the place, mainly wrt /proc interfaces (switch create_proc_entry to proc_create(), get rid of the deprecated create_proc_read_entry() in favor of using proc_create_data() and seq_file etc). 7kloc removed. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (204 commits) don't bother with deferred freeing of fdtables proc: Move non-public stuff from linux/proc_fs.h to fs/proc/internal.h proc: Make the PROC_I() and PDE() macros internal to procfs proc: Supply a function to remove a proc entry by PDE take cgroup_open() and cpuset_open() to fs/proc/base.c ppc: Clean up scanlog ppc: Clean up rtas_flash driver somewhat hostap: proc: Use remove_proc_subtree() drm: proc: Use remove_proc_subtree() drm: proc: Use minor->index to label things, not PDE->name drm: Constify drm_proc_list[] zoran: Don't print proc_dir_entry data in debug reiserfs: Don't access the proc_dir_entry in r_open(), r_start() r_show() proc: Supply an accessor for getting the data from a PDE's parent airo: Use remove_proc_subtree() rtl8192u: Don't need to save device proc dir PDE rtl8187se: Use a dir under /proc/net/r8180/ proc: Add proc_mkdir_data() proc: Move some bits from linux/proc_fs.h to linux/{of.h,signal.h,tty.h} proc: Move PDE_NET() to fs/proc/proc_net.c ...
| * new helper: read_code()Al Viro2013-04-291-0/+9
| | | | | | | | | | | | | | | | switch binfmts that use ->read() to that (and to kernel_read() in several cases in binfmt_flat - sure, it's nommu, but still, doing ->read() into kmalloc'ed buffer...) Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | exec: do not abuse ->cred_guard_mutex in threadgroup_lock()Oleg Nesterov2013-04-301-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | threadgroup_lock() takes signal->cred_guard_mutex to ensure that thread_group_leader() is stable. This doesn't look nice, the scope of this lock in do_execve() is huge. And as Dave pointed out this can lead to deadlock, we have the following dependencies: do_execve: cred_guard_mutex -> i_mutex cgroup_mount: i_mutex -> cgroup_mutex attach_task_by_pid: cgroup_mutex -> cred_guard_mutex Change de_thread() to take threadgroup_change_begin() around the switch-the-leader code and change threadgroup_lock() to avoid ->cred_guard_mutex. Note that de_thread() can't sleep with ->group_rwsem held, this can obviously deadlock with the exiting leader if the writer is active, so it does threadgroup_change_end() before schedule(). Reported-by: Dave Jones <davej@redhat.com> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | set_task_comm: kill the pointless memset() + wmb()Oleg Nesterov2013-04-301-10/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | set_task_comm() does memset() + wmb() before strlcpy(). This buys nothing and to add to the confusion, the comment is wrong. - We do not need memset() to be "safe from non-terminating string reads", the final char is always zero and we never change it. - wmb() is paired with nothing, it cannot prevent from printing the mixture of the old/new data unless the reader takes the lock. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: John Stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: allow arch code to control the user page table ceilingHugh Dickins2013-04-291-2/+2
|/ | | | | | | | | | | | | | | | | On architectures where a pgd entry may be shared between user and kernel (e.g. ARM+LPAE), freeing page tables needs a ceiling other than 0. This patch introduces a generic USER_PGTABLES_CEILING that arch code can override. It is the responsibility of the arch code setting the ceiling to ensure the complete freeing of the page tables (usually in pgd_free()). [catalin.marinas@arm.com: commit log; shift_arg_pages(), asm-generic/pgtables.h changes] Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: <stable@vger.kernel.org> [3.3+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* coredump: remove redundant defines for dumpable statesKees Cook2013-02-271-5/+5
| | | | | | | | | | | | | | | | | | The existing SUID_DUMP_* defines duplicate the newer SUID_DUMPABLE_* defines introduced in 54b501992dd2 ("coredump: warn about unsafe suid_dumpable / core_pattern combo"). Remove the new ones, and use the prior values instead. Signed-off-by: Kees Cook <keescook@chromium.org> Reported-by: Chen Gang <gang.chen@asianux.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alan Cox <alan@linux.intel.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Doug Ledford <dledford@redhat.com> Cc: Serge Hallyn <serge.hallyn@canonical.com> Cc: James Morris <james.l.morris@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs/exec.c: make bprm_mm_init() staticYuanhan Liu2013-02-261-1/+1
| | | | | | | | There is only one user of bprm_mm_init, and it's inside the same file. Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* new helper: file_inode(file)Al Viro2013-02-221-4/+4
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* fs/exec.c: work around icc miscompilationXi Wang2013-01-111-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | The tricky problem is this check: if (i++ >= max) icc (mis)optimizes this check as: if (++i > max) The check now becomes a no-op since max is MAX_ARG_STRINGS (0x7FFFFFFF). This is "allowed" by the C standard, assuming i++ never overflows, because signed integer overflow is undefined behavior. This optimization effectively reverts the previous commit 362e6663ef23 ("exec.c, compat.c: fix count(), compat_count() bounds checking") that tries to fix the check. This patch simply moves ++ after the check. Signed-off-by: Xi Wang <xi.wang@gmail.com> Cc: Jason Baron <jbaron@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'akpm' (Andrew's patch-bomb)Linus Torvalds2012-12-201-0/+15
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge the rest of Andrew's patches for -rc1: "A bunch of fixes and misc missed-out-on things. That'll do for -rc1. I still have a batch of IPC patches which still have a possible bug report which I'm chasing down." * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (25 commits) keys: use keyring_alloc() to create module signing keyring keys: fix unreachable code sendfile: allows bypassing of notifier events SGI-XP: handle non-fatal traps fat: fix incorrect function comment Documentation: ABI: remove testing/sysfs-devices-node proc: fix inconsistent lock state linux/kernel.h: fix DIV_ROUND_CLOSEST with unsigned divisors memcg: don't register hotcpu notifier from ->css_alloc() checkpatch: warn on uapi #includes that #include <uapi/... revert "rtc: recycle id when unloading a rtc driver" mm: clean up transparent hugepage sysfs error messages hfsplus: add error message for the case of failure of sync fs in delayed_sync_fs() method hfsplus: rework processing of hfs_btree_write() returned error hfsplus: rework processing errors in hfsplus_free_extents() hfsplus: avoid crash on failed block map free kcmp: include linux/ptrace.h drivers/rtc/rtc-imxdi.c: must include <linux/spinlock.h> mm: cma: WARN if freed memory is still in use exec: do not leave bprm->interp on stack ...
| * exec: do not leave bprm->interp on stackKees Cook2012-12-201-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a series of scripts are executed, each triggering module loading via unprintable bytes in the script header, kernel stack contents can leak into the command line. Normally execution of binfmt_script and binfmt_misc happens recursively. However, when modules are enabled, and unprintable bytes exist in the bprm->buf, execution will restart after attempting to load matching binfmt modules. Unfortunately, the logic in binfmt_script and binfmt_misc does not expect to get restarted. They leave bprm->interp pointing to their local stack. This means on restart bprm->interp is left pointing into unused stack memory which can then be copied into the userspace argv areas. After additional study, it seems that both recursion and restart remains the desirable way to handle exec with scripts, misc, and modules. As such, we need to protect the changes to interp. This changes the logic to require allocation for any changes to the bprm->interp. To avoid adding a new kmalloc to every exec, the default value is left as-is. Only when passing through binfmt_script or binfmt_misc does an allocation take place. For a proof of concept, see DoTest.sh from: http://www.halfdog.net/Security/2012/LinuxKernelBinfmtScriptStackDataDisclosure/ Signed-off-by: Kees Cook <keescook@chromium.org> Cc: halfdog <me@halfdog.net> Cc: P J P <ppandit@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge branch 'for-linus' of ↵Linus Torvalds2012-12-201-21/+0
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal Pull signal handling cleanups from Al Viro: "sigaltstack infrastructure + conversion for x86, alpha and um, COMPAT_SYSCALL_DEFINE infrastructure. Note that there are several conflicts between "unify SS_ONSTACK/SS_DISABLE definitions" and UAPI patches in mainline; resolution is trivial - just remove definitions of SS_ONSTACK and SS_DISABLED from arch/*/uapi/asm/signal.h; they are all identical and include/uapi/linux/signal.h contains the unified variant." Fixed up conflicts as per Al. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: alpha: switch to generic sigaltstack new helpers: __save_altstack/__compat_save_altstack, switch x86 and um to those generic compat_sys_sigaltstack() introduce generic sys_sigaltstack(), switch x86 and um to it new helper: compat_user_stack_pointer() new helper: restore_altstack() unify SS_ONSTACK/SS_DISABLE definitions new helper: current_user_stack_pointer() missing user_stack_pointer() instances Bury the conditionals from kernel_thread/kernel_execve series COMPAT_SYSCALL_DEFINE: infrastructure
| * Bury the conditionals from kernel_thread/kernel_execve seriesAl Viro2012-12-191-21/+0
| | | | | | | | | | | | | | | | | | | | | | | | All architectures have CONFIG_GENERIC_KERNEL_THREAD CONFIG_GENERIC_KERNEL_EXECVE __ARCH_WANT_SYS_EXECVE None of them have __ARCH_WANT_KERNEL_EXECVE and there are only two callers of kernel_execve() (which is a trivial wrapper for do_execve() now) left. Kill the conditionals and make both callers use do_execve(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | Merge branch 'akpm' (Andrew's patch-bomb)Linus Torvalds2012-12-171-5/+5
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge misc patches from Andrew Morton: "Incoming: - lots of misc stuff - backlight tree updates - lib/ updates - Oleg's percpu-rwsem changes - checkpatch - rtc - aoe - more checkpoint/restart support I still have a pile of MM stuff pending - Pekka should be merging later today after which that is good to go. A number of other things are twiddling thumbs awaiting maintainer merges." * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (180 commits) scatterlist: don't BUG when we can trivially return a proper error. docs: update documentation about /proc/<pid>/fdinfo/<fd> fanotify output fs, fanotify: add @mflags field to fanotify output docs: add documentation about /proc/<pid>/fdinfo/<fd> output fs, notify: add procfs fdinfo helper fs, exportfs: add exportfs_encode_inode_fh() helper fs, exportfs: escape nil dereference if no s_export_op present fs, epoll: add procfs fdinfo helper fs, eventfd: add procfs fdinfo helper procfs: add ability to plug in auxiliary fdinfo providers tools/testing/selftests/kcmp/kcmp_test.c: print reason for failure in kcmp_test breakpoint selftests: print failure status instead of cause make error kcmp selftests: print fail status instead of cause make error kcmp selftests: make run_tests fix mem-hotplug selftests: print failure status instead of cause make error cpu-hotplug selftests: print failure status instead of cause make error mqueue selftests: print failure status instead of cause make error vm selftests: print failure status instead of cause make error ubifs: use prandom_bytes mtd: nandsim: use prandom_bytes ...
| * | exec: use -ELOOP for max recursion depthKees Cook2012-12-171-5/+5
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To avoid an explosion of request_module calls on a chain of abusive scripts, fail maximum recursion with -ELOOP instead of -ENOEXEC. As soon as maximum recursion depth is hit, the error will fail all the way back up the chain, aborting immediately. This also has the side-effect of stopping the user's shell from attempting to reexecute the top-level file as a shell script. As seen in the dash source: if (cmd != path_bshell && errno == ENOEXEC) { *argv-- = cmd; *argv = cmd = path_bshell; goto repeat; } The above logic was designed for running scripts automatically that lacked the "#!" header, not to re-try failed recursion. On a legitimate -ENOEXEC, things continue to behave as the shell expects. Additionally, when tracking recursion, the binfmt handlers should not be involved. The recursion being tracked is the depth of calls through search_binary_handler(), so that function should be exclusively responsible for tracking the depth. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: halfdog <me@halfdog.net> Cc: P J P <ppandit@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge branch 'for-linus' of ↵Linus Torvalds2012-12-171-6/+3
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull user namespace changes from Eric Biederman: "While small this set of changes is very significant with respect to containers in general and user namespaces in particular. The user space interface is now complete. This set of changes adds support for unprivileged users to create user namespaces and as a user namespace root to create other namespaces. The tyranny of supporting suid root preventing unprivileged users from using cool new kernel features is broken. This set of changes completes the work on setns, adding support for the pid, user, mount namespaces. This set of changes includes a bunch of basic pid namespace cleanups/simplifications. Of particular significance is the rework of the pid namespace cleanup so it no longer requires sending out tendrils into all kinds of unexpected cleanup paths for operation. At least one case of broken error handling is fixed by this cleanup. The files under /proc/<pid>/ns/ have been converted from regular files to magic symlinks which prevents incorrect caching by the VFS, ensuring the files always refer to the namespace the process is currently using and ensuring that the ptrace_mayaccess permission checks are always applied. The files under /proc/<pid>/ns/ have been given stable inode numbers so it is now possible to see if different processes share the same namespaces. Through the David Miller's net tree are changes to relax many of the permission checks in the networking stack to allowing the user namespace root to usefully use the networking stack. Similar changes for the mount namespace and the pid namespace are coming through my tree. Two small changes to add user namespace support were commited here adn in David Miller's -net tree so that I could complete the work on the /proc/<pid>/ns/ files in this tree. Work remains to make it safe to build user namespaces and 9p, afs, ceph, cifs, coda, gfs2, ncpfs, nfs, nfsd, ocfs2, and xfs so the Kconfig guard remains in place preventing that user namespaces from being built when any of those filesystems are enabled. Future design work remains to allow root users outside of the initial user namespace to mount more than just /proc and /sys." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (38 commits) proc: Usable inode numbers for the namespace file descriptors. proc: Fix the namespace inode permission checks. proc: Generalize proc inode allocation userns: Allow unprivilged mounts of proc and sysfs userns: For /proc/self/{uid,gid}_map derive the lower userns from the struct file procfs: Print task uids and gids in the userns that opened the proc file userns: Implement unshare of the user namespace userns: Implent proc namespace operations userns: Kill task_user_ns userns: Make create_new_namespaces take a user_ns parameter userns: Allow unprivileged use of setns. userns: Allow unprivileged users to create new namespaces userns: Allow setting a userns mapping to your current uid. userns: Allow chown and setgid preservation userns: Allow unprivileged users to create user namespaces. userns: Ignore suid and sgid on binaries if the uid or gid can not be mapped userns: fix return value on mntns_install() failure vfs: Allow unprivileged manipulation of the mount namespace. vfs: Only support slave subtrees across different user namespaces vfs: Add a user namespace reference from struct mnt_namespace ...
| * userns: Ignore suid and sgid on binaries if the uid or gid can not be mappedEric W. Biederman2012-11-191-6/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When performing an exec where the binary lives in one user namespace and the execing process lives in another usre namespace there is the possibility that the target uids can not be represented. Instead of failing the exec simply ignore the suid/sgid bits and run the binary with lower privileges. We already do this in the case of MNT_NOSUID so this should be a well tested code path. As the user and group are not changed this should not introduce any security issues. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
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