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2017-01-19sysctl: Drop reference added by grab_header in proc_sys_readdirZhou Chengming
commit 93362fa47fe98b62e4a34ab408c4a418432e7939 upstream. Fixes CVE-2016-9191, proc_sys_readdir doesn't drop reference added by grab_header when return from !dir_emit_dots path. It can cause any path called unregister_sysctl_table will wait forever. The calltrace of CVE-2016-9191: [ 5535.960522] Call Trace: [ 5535.963265] [<ffffffff817cdaaf>] schedule+0x3f/0xa0 [ 5535.968817] [<ffffffff817d33fb>] schedule_timeout+0x3db/0x6f0 [ 5535.975346] [<ffffffff817cf055>] ? wait_for_completion+0x45/0x130 [ 5535.982256] [<ffffffff817cf0d3>] wait_for_completion+0xc3/0x130 [ 5535.988972] [<ffffffff810d1fd0>] ? wake_up_q+0x80/0x80 [ 5535.994804] [<ffffffff8130de64>] drop_sysctl_table+0xc4/0xe0 [ 5536.001227] [<ffffffff8130de17>] drop_sysctl_table+0x77/0xe0 [ 5536.007648] [<ffffffff8130decd>] unregister_sysctl_table+0x4d/0xa0 [ 5536.014654] [<ffffffff8130deff>] unregister_sysctl_table+0x7f/0xa0 [ 5536.021657] [<ffffffff810f57f5>] unregister_sched_domain_sysctl+0x15/0x40 [ 5536.029344] [<ffffffff810d7704>] partition_sched_domains+0x44/0x450 [ 5536.036447] [<ffffffff817d0761>] ? __mutex_unlock_slowpath+0x111/0x1f0 [ 5536.043844] [<ffffffff81167684>] rebuild_sched_domains_locked+0x64/0xb0 [ 5536.051336] [<ffffffff8116789d>] update_flag+0x11d/0x210 [ 5536.057373] [<ffffffff817cf61f>] ? mutex_lock_nested+0x2df/0x450 [ 5536.064186] [<ffffffff81167acb>] ? cpuset_css_offline+0x1b/0x60 [ 5536.070899] [<ffffffff810fce3d>] ? trace_hardirqs_on+0xd/0x10 [ 5536.077420] [<ffffffff817cf61f>] ? mutex_lock_nested+0x2df/0x450 [ 5536.084234] [<ffffffff8115a9f5>] ? css_killed_work_fn+0x25/0x220 [ 5536.091049] [<ffffffff81167ae5>] cpuset_css_offline+0x35/0x60 [ 5536.097571] [<ffffffff8115aa2c>] css_killed_work_fn+0x5c/0x220 [ 5536.104207] [<ffffffff810bc83f>] process_one_work+0x1df/0x710 [ 5536.110736] [<ffffffff810bc7c0>] ? process_one_work+0x160/0x710 [ 5536.117461] [<ffffffff810bce9b>] worker_thread+0x12b/0x4a0 [ 5536.123697] [<ffffffff810bcd70>] ? process_one_work+0x710/0x710 [ 5536.130426] [<ffffffff810c3f7e>] kthread+0xfe/0x120 [ 5536.135991] [<ffffffff817d4baf>] ret_from_fork+0x1f/0x40 [ 5536.142041] [<ffffffff810c3e80>] ? kthread_create_on_node+0x230/0x230 One cgroup maintainer mentioned that "cgroup is trying to offline a cpuset css, which takes place under cgroup_mutex. The offlining ends up trying to drain active usages of a sysctl table which apprently is not happening." The real reason is that proc_sys_readdir doesn't drop reference added by grab_header when return from !dir_emit_dots path. So this cpuset offline path will wait here forever. See here for details: http://www.openwall.com/lists/oss-security/2016/11/04/13 Fixes: f0c3b5093add ("[readdir] convert procfs") Reported-by: CAI Qian <caiqian@redhat.com> Tested-by: Yang Shukui <yangshukui@huawei.com> Signed-off-by: Zhou Chengming <zhouchengming1@huawei.com> Acked-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-28proc: fix NULL dereference when reading /proc/<pid>/auxvLeon Yu
Reading auxv of any kernel thread results in NULL pointer dereferencing in auxv_read() where mm can be NULL. Fix that by checking for NULL mm and bailing out early. This is also the original behavior changed by recent commit c5317167854e ("proc: switch auxv to use of __mem_open()"). # cat /proc/2/auxv Unable to handle kernel NULL pointer dereference at virtual address 000000a8 Internal error: Oops: 17 [#1] PREEMPT SMP ARM CPU: 3 PID: 113 Comm: cat Not tainted 4.9.0-rc1-ARCH+ #1 Hardware name: BCM2709 task: ea3b0b00 task.stack: e99b2000 PC is at auxv_read+0x24/0x4c LR is at do_readv_writev+0x2fc/0x37c Process cat (pid: 113, stack limit = 0xe99b2210) Call chain: auxv_read do_readv_writev vfs_readv default_file_splice_read splice_direct_to_actor do_splice_direct do_sendfile SyS_sendfile64 ret_fast_syscall Fixes: c5317167854e ("proc: switch auxv to use of __mem_open()") Link: http://lkml.kernel.org/r/1476966200-14457-1-git-send-email-chianglungyu@gmail.com Signed-off-by: Leon Yu <chianglungyu@gmail.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Kees Cook <keescook@chromium.org> Cc: John Stultz <john.stultz@linaro.org> Cc: Mateusz Guzik <mguzik@redhat.com> Cc: Janis Danisevskis <jdanis@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-25proc: don't use FOLL_FORCE for reading cmdline and environmentLinus Torvalds
Now that Lorenzo cleaned things up and made the FOLL_FORCE users explicit, it becomes obvious how some of them don't really need FOLL_FORCE at all. So remove FOLL_FORCE from the proc code that reads the command line and arguments from user space. The mem_rw() function actually does want FOLL_FORCE, because gdd (and possibly many other debuggers) use it as a much more convenient version of PTRACE_PEEKDATA, but we should consider making the FOLL_FORCE part conditional on actually being a ptracer. This does not actually do that, just moves adds a comment to that effect and moves the gup_flags settings next to each other. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-22Merge branch 'mm-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull vmap stack fixes from Ingo Molnar: "This is fallout from CONFIG_HAVE_ARCH_VMAP_STACK=y on x86: stack accesses that used to be just somewhat questionable are now totally buggy. These changes try to do it without breaking the ABI: the fields are left there, they are just reporting zero, or reporting narrower information (the maps file change)" * 'mm-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: mm: Change vm_is_stack_for_task() to vm_is_stack_for_current() fs/proc: Stop trying to report thread stacks fs/proc: Stop reporting eip and esp in /proc/PID/stat mm/numa: Remove duplicated include from mprotect.c
2016-10-20fs/proc: Stop trying to report thread stacksAndy Lutomirski
This reverts more of: b76437579d13 ("procfs: mark thread stack correctly in proc/<pid>/maps") ... which was partially reverted by: 65376df58217 ("proc: revert /proc/<pid>/maps [stack:TID] annotation") Originally, /proc/PID/task/TID/maps was the same as /proc/TID/maps. In current kernels, /proc/PID/maps (or /proc/TID/maps even for threads) shows "[stack]" for VMAs in the mm's stack address range. In contrast, /proc/PID/task/TID/maps uses KSTK_ESP to guess the target thread's stack's VMA. This is racy, probably returns garbage and, on arches with CONFIG_TASK_INFO_IN_THREAD=y, is also crash-prone: KSTK_ESP is not safe to use on tasks that aren't known to be running ordinary process-context kernel code. This patch removes the difference and just shows "[stack]" for VMAs in the mm's stack range. This is IMO much more sensible -- the actual "stack" address really is treated specially by the VM code, and the current thread stack isn't even well-defined for programs that frequently switch stacks on their own. Reported-by: Jann Horn <jann@thejh.net> Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Linux API <linux-api@vger.kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tycho Andersen <tycho.andersen@canonical.com> Link: http://lkml.kernel.org/r/3e678474ec14e0a0ec34c611016753eea2e1b8ba.1475257877.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-20fs/proc: Stop reporting eip and esp in /proc/PID/statAndy Lutomirski
Reporting these fields on a non-current task is dangerous. If the task is in any state other than normal kernel code, they may contain garbage or even kernel addresses on some architectures. (x86_64 used to do this. I bet lots of architectures still do.) With CONFIG_THREAD_INFO_IN_TASK=y, it can OOPS, too. As far as I know, there are no use programs that make any material use of these fields, so just get rid of them. Reported-by: Jann Horn <jann@thejh.net> Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Linux API <linux-api@vger.kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Cc: Tycho Andersen <tycho.andersen@canonical.com> Link: http://lkml.kernel.org/r/a5fed4c3f4e33ed25d4bb03567e329bc5a712bcc.1475257877.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-19mm: replace access_remote_vm() write parameter with gup_flagsLorenzo Stoakes
This removes the 'write' argument from access_remote_vm() and replaces it with 'gup_flags' as use of this function previously silently implied FOLL_FORCE, whereas after this patch callers explicitly pass this flag. We make this explicit as use of FOLL_FORCE can result in surprising behaviour (and hence bugs) within the mm subsystem. Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull more vfs updates from Al Viro: ">rename2() work from Miklos + current_time() from Deepa" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs: Replace current_fs_time() with current_time() fs: Replace CURRENT_TIME_SEC with current_time() for inode timestamps fs: Replace CURRENT_TIME with current_time() for inode timestamps fs: proc: Delete inode time initializations in proc_alloc_inode() vfs: Add current_time() api vfs: add note about i_op->rename changes to porting fs: rename "rename2" i_op to "rename" vfs: remove unused i_op->rename fs: make remaining filesystems use .rename2 libfs: support RENAME_NOREPLACE in simple_rename() fs: support RENAME_NOREPLACE for local filesystems ncpfs: fix unused variable warning
2016-10-11Merge remote-tracking branch 'ovl/rename2' into for-linusAl Viro
2016-10-10Merge branch 'work.misc' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull misc vfs updates from Al Viro: "Assorted misc bits and pieces. There are several single-topic branches left after this (rename2 series from Miklos, current_time series from Deepa Dinamani, xattr series from Andreas, uaccess stuff from from me) and I'd prefer to send those separately" * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (39 commits) proc: switch auxv to use of __mem_open() hpfs: support FIEMAP cifs: get rid of unused arguments of CIFSSMBWrite() posix_acl: uapi header split posix_acl: xattr representation cleanups fs/aio.c: eliminate redundant loads in put_aio_ring_file fs/internal.h: add const to ns_dentry_operations declaration compat: remove compat_printk() fs/buffer.c: make __getblk_slow() static proc: unsigned file descriptors fs/file: more unsigned file descriptors fs: compat: remove redundant check of nr_segs cachefiles: Fix attempt to read i_blocks after deleting file [ver #2] cifs: don't use memcpy() to copy struct iov_iter get rid of separate multipage fault-in primitives fs: Avoid premature clearing of capabilities fs: Give dentry to inode_change_ok() instead of inode fuse: Propagate dentry down to inode_change_ok() ceph: Propagate dentry down to inode_change_ok() xfs: Propagate dentry down to inode_change_ok() ...
2016-10-08Merge remote-tracking branch 'jk/vfs' into work.miscAl Viro
2016-10-08cred: simpler, 1D supplementary groupsAlexey Dobriyan
Current supplementary groups code can massively overallocate memory and is implemented in a way so that access to individual gid is done via 2D array. If number of gids is <= 32, memory allocation is more or less tolerable (140/148 bytes). But if it is not, code allocates full page (!) regardless and, what's even more fun, doesn't reuse small 32-entry array. 2D array means dependent shifts, loads and LEAs without possibility to optimize them (gid is never known at compile time). All of the above is unnecessary. Switch to the usual trailing-zero-len-array scheme. Memory is allocated with kmalloc/vmalloc() and only as much as needed. Accesses become simpler (LEA 8(gi,idx,4) or even without displacement). Maximum number of gids is 65536 which translates to 256KB+8 bytes. I think kernel can handle such allocation. On my usual desktop system with whole 9 (nine) aux groups, struct group_info shrinks from 148 bytes to 44 bytes, yay! Nice side effects: - "gi->gid[i]" is shorter than "GROUP_AT(gi, i)", less typing, - fix little mess in net/ipv4/ping.c should have been using GROUP_AT macro but this point becomes moot, - aux group allocation is persistent and should be accounted as such. Link: http://lkml.kernel.org/r/20160817201927.GA2096@p183.telecom.by Signed-off-by: Alexey Dobriyan <adobriyan@gmail.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>
2016-10-08mm, proc: fix region lost in /proc/self/smapsRobert Ho
Recently, Redhat reported that nvml test suite failed on QEMU/KVM, more detailed info please refer to: https://bugzilla.redhat.com/show_bug.cgi?id=1365721 Actually, this bug is not only for NVDIMM/DAX but also for any other file systems. This simple test case abstracted from nvml can easily reproduce this bug in common environment: -------------------------- testcase.c ----------------------------- int is_pmem_proc(const void *addr, size_t len) { const char *caddr = addr; FILE *fp; if ((fp = fopen("/proc/self/smaps", "r")) == NULL) { printf("!/proc/self/smaps"); return 0; } int retval = 0; /* assume false until proven otherwise */ char line[PROCMAXLEN]; /* for fgets() */ char *lo = NULL; /* beginning of current range in smaps file */ char *hi = NULL; /* end of current range in smaps file */ int needmm = 0; /* looking for mm flag for current range */ while (fgets(line, PROCMAXLEN, fp) != NULL) { static const char vmflags[] = "VmFlags:"; static const char mm[] = " wr"; /* check for range line */ if (sscanf(line, "%p-%p", &lo, &hi) == 2) { if (needmm) { /* last range matched, but no mm flag found */ printf("never found mm flag.\n"); break; } else if (caddr < lo) { /* never found the range for caddr */ printf("#######no match for addr %p.\n", caddr); break; } else if (caddr < hi) { /* start address is in this range */ size_t rangelen = (size_t)(hi - caddr); /* remember that matching has started */ needmm = 1; /* calculate remaining range to search for */ if (len > rangelen) { len -= rangelen; caddr += rangelen; printf("matched %zu bytes in range " "%p-%p, %zu left over.\n", rangelen, lo, hi, len); } else { len = 0; printf("matched all bytes in range " "%p-%p.\n", lo, hi); } } } else if (needmm && strncmp(line, vmflags, sizeof(vmflags) - 1) == 0) { if (strstr(&line[sizeof(vmflags) - 1], mm) != NULL) { printf("mm flag found.\n"); if (len == 0) { /* entire range matched */ retval = 1; break; } needmm = 0; /* saw what was needed */ } else { /* mm flag not set for some or all of range */ printf("range has no mm flag.\n"); break; } } } fclose(fp); printf("returning %d.\n", retval); return retval; } void *Addr; size_t Size; /* * worker -- the work each thread performs */ static void * worker(void *arg) { int *ret = (int *)arg; *ret = is_pmem_proc(Addr, Size); return NULL; } int main(int argc, char *argv[]) { if (argc < 2 || argc > 3) { printf("usage: %s file [env].\n", argv[0]); return -1; } int fd = open(argv[1], O_RDWR); struct stat stbuf; fstat(fd, &stbuf); Size = stbuf.st_size; Addr = mmap(0, stbuf.st_size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); close(fd); pthread_t threads[NTHREAD]; int ret[NTHREAD]; /* kick off NTHREAD threads */ for (int i = 0; i < NTHREAD; i++) pthread_create(&threads[i], NULL, worker, &ret[i]); /* wait for all the threads to complete */ for (int i = 0; i < NTHREAD; i++) pthread_join(threads[i], NULL); /* verify that all the threads return the same value */ for (int i = 1; i < NTHREAD; i++) { if (ret[0] != ret[i]) { printf("Error i %d ret[0] = %d ret[i] = %d.\n", i, ret[0], ret[i]); } } printf("%d", ret[0]); return 0; } It failed as some threads can not find the memory region in "/proc/self/smaps" which is allocated in the main process It is caused by proc fs which uses 'file->version' to indicate the VMA that is the last one has already been handled by read() system call. When the next read() issues, it uses the 'version' to find the VMA, then the next VMA is what we want to handle, the related code is as follows: if (last_addr) { vma = find_vma(mm, last_addr); if (vma && (vma = m_next_vma(priv, vma))) return vma; } However, VMA will be lost if the last VMA is gone, e.g: The process VMA list is A->B->C->D CPU 0 CPU 1 read() system call handle VMA B version = B return to userspace unmap VMA B issue read() again to continue to get the region info find_vma(version) will get VMA C m_next_vma(C) will get VMA D handle D !!! VMA C is lost !!! In order to fix this bug, we make 'file->version' indicate the end address of the current VMA. m_start will then look up a vma which with vma_start < last_vm_end and moves on to the next vma if we found the same or an overlapping vma. This will guarantee that we will not miss an exclusive vma but we can still miss one if the previous vma was shrunk. This is acceptable because guaranteeing "never miss a vma" is simply not feasible. User has to cope with some inconsistencies if the file is not read in one go. [mhocko@suse.com: changelog fixes] Link: http://lkml.kernel.org/r/1475296958-27652-1-git-send-email-robert.hu@intel.com Acked-by: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com> Signed-off-by: Robert Hu <robert.hu@intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Stefan Hajnoczi <stefanha@redhat.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-08proc: fix timerslack_ns CAP_SYS_NICE check when adjusting selfJohn Stultz
In changing from checking ptrace_may_access(p, PTRACE_MODE_ATTACH_FSCREDS) to capable(CAP_SYS_NICE), I missed that ptrace_my_access succeeds when p == current, but the CAP_SYS_NICE doesn't. Thus while the previous commit was intended to loosen the needed privileges to modify a processes timerslack, it needlessly restricted a task modifying its own timerslack via the proc/<tid>/timerslack_ns (which is permitted also via the PR_SET_TIMERSLACK method). This patch corrects this by checking if p == current before checking the CAP_SYS_NICE value. This patch applies on top of my two previous patches currently in -mm Link: http://lkml.kernel.org/r/1471906870-28624-1-git-send-email-john.stultz@linaro.org Signed-off-by: John Stultz <john.stultz@linaro.org> Acked-by: Kees Cook <keescook@chromium.org> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Oren Laadan <orenl@cellrox.com> Cc: Ruchi Kandoi <kandoiruchi@google.com> Cc: Rom Lemarchand <romlem@android.com> Cc: Todd Kjos <tkjos@google.com> Cc: Colin Cross <ccross@android.com> Cc: Nick Kralevich <nnk@google.com> Cc: Dmitry Shmidt <dimitrysh@google.com> Cc: Elliott Hughes <enh@google.com> Cc: Android Kernel Team <kernel-team@android.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-08proc: add LSM hook checks to /proc/<tid>/timerslack_nsJohn Stultz
As requested, this patch checks the existing LSM hooks task_getscheduler/task_setscheduler when reading or modifying the task's timerslack value. Previous versions added new get/settimerslack LSM hooks, but since they checked the same PROCESS__SET/GETSCHED values as existing hooks, it was suggested we just use the existing ones. Link: http://lkml.kernel.org/r/1469132667-17377-2-git-send-email-john.stultz@linaro.org Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: Kees Cook <keescook@chromium.org> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Oren Laadan <orenl@cellrox.com> Cc: Ruchi Kandoi <kandoiruchi@google.com> Cc: Rom Lemarchand <romlem@android.com> Cc: Todd Kjos <tkjos@google.com> Cc: Colin Cross <ccross@android.com> Cc: Nick Kralevich <nnk@google.com> Cc: Dmitry Shmidt <dimitrysh@google.com> Cc: Elliott Hughes <enh@google.com> Cc: James Morris <jmorris@namei.org> Cc: Android Kernel Team <kernel-team@android.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-08proc: relax /proc/<tid>/timerslack_ns capability requirementsJohn Stultz
When an interface to allow a task to change another tasks timerslack was first proposed, it was suggested that something greater then CAP_SYS_NICE would be needed, as a task could be delayed further then what normally could be done with nice adjustments. So CAP_SYS_PTRACE was adopted instead for what became the /proc/<tid>/timerslack_ns interface. However, for Android (where this feature originates), giving the system_server CAP_SYS_PTRACE would allow it to observe and modify all tasks memory. This is considered too high a privilege level for only needing to change the timerslack. After some discussion, it was realized that a CAP_SYS_NICE process can set a task as SCHED_FIFO, so they could fork some spinning processes and set them all SCHED_FIFO 99, in effect delaying all other tasks for an infinite amount of time. So as a CAP_SYS_NICE task can already cause trouble for other tasks, using it as a required capability for accessing and modifying /proc/<tid>/timerslack_ns seems sufficient. Thus, this patch loosens the capability requirements to CAP_SYS_NICE and removes CAP_SYS_PTRACE, simplifying some of the code flow as well. This is technically an ABI change, but as the feature just landed in 4.6, I suspect no one is yet using it. Link: http://lkml.kernel.org/r/1469132667-17377-1-git-send-email-john.stultz@linaro.org Signed-off-by: John Stultz <john.stultz@linaro.org> Reviewed-by: Nick Kralevich <nnk@google.com> Acked-by: Serge Hallyn <serge@hallyn.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Kees Cook <keescook@chromium.org> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Oren Laadan <orenl@cellrox.com> Cc: Ruchi Kandoi <kandoiruchi@google.com> Cc: Rom Lemarchand <romlem@android.com> Cc: Todd Kjos <tkjos@google.com> Cc: Colin Cross <ccross@android.com> Cc: Nick Kralevich <nnk@google.com> Cc: Dmitry Shmidt <dimitrysh@google.com> Cc: Elliott Hughes <enh@google.com> Cc: Android Kernel Team <kernel-team@android.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-08meminfo: break apart a very long seq_printf with #ifdefsJoe Perches
Use a specific routine to emit most lines so that the code is easier to read and maintain. akpm: text data bss dec hex filename 2976 8 0 2984 ba8 fs/proc/meminfo.o before 2669 8 0 2677 a75 fs/proc/meminfo.o after Link: http://lkml.kernel.org/r/8fce7fdef2ba081a4ef531594e97da8a9feebb58.1470810406.git.joe@perches.com Signed-off-by: Joe Perches <joe@perches.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Alexey Dobriyan <adobriyan@gmail.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>
2016-10-08seq/proc: modify seq_put_decimal_[u]ll to take a const char *, not charJoe Perches
Allow some seq_puts removals by taking a string instead of a single char. [akpm@linux-foundation.org: update vmstat_show(), per Joe] Link: http://lkml.kernel.org/r/667e1cf3d436de91a5698170a1e98d882905e956.1470704995.git.joe@perches.com Signed-off-by: Joe Perches <joe@perches.com> Cc: Joe Perches <joe@perches.com> Cc: Andi Kleen <andi@firstfloor.org> 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>
2016-10-08proc: faster /proc/*/statusAlexey Dobriyan
top(1) opens the following files for every PID: /proc/*/stat /proc/*/statm /proc/*/status This patch switches /proc/*/status away from seq_printf(). The result is 13.5% speedup. Benchmark is open("/proc/self/status")+read+close 1.000.000 million times. BEFORE $ perf stat -r 10 taskset -c 3 ./proc-self-status Performance counter stats for 'taskset -c 3 ./proc-self-status' (10 runs): 10748.474301 task-clock (msec) # 0.954 CPUs utilized ( +- 0.91% ) 12 context-switches # 0.001 K/sec ( +- 1.09% ) 1 cpu-migrations # 0.000 K/sec 104 page-faults # 0.010 K/sec ( +- 0.45% ) 37,424,127,876 cycles # 3.482 GHz ( +- 0.04% ) 8,453,010,029 stalled-cycles-frontend # 22.59% frontend cycles idle ( +- 0.12% ) 3,747,609,427 stalled-cycles-backend # 10.01% backend cycles idle ( +- 0.68% ) 65,632,764,147 instructions # 1.75 insn per cycle # 0.13 stalled cycles per insn ( +- 0.00% ) 13,981,324,775 branches # 1300.773 M/sec ( +- 0.00% ) 138,967,110 branch-misses # 0.99% of all branches ( +- 0.18% ) 11.263885428 seconds time elapsed ( +- 0.04% ) ^^^^^^^^^^^^ AFTER $ perf stat -r 10 taskset -c 3 ./proc-self-status Performance counter stats for 'taskset -c 3 ./proc-self-status' (10 runs): 9010.521776 task-clock (msec) # 0.925 CPUs utilized ( +- 1.54% ) 11 context-switches # 0.001 K/sec ( +- 1.54% ) 1 cpu-migrations # 0.000 K/sec ( +- 11.11% ) 103 page-faults # 0.011 K/sec ( +- 0.60% ) 32,352,310,603 cycles # 3.591 GHz ( +- 0.07% ) 7,849,199,578 stalled-cycles-frontend # 24.26% frontend cycles idle ( +- 0.27% ) 3,269,738,842 stalled-cycles-backend # 10.11% backend cycles idle ( +- 0.73% ) 56,012,163,567 instructions # 1.73 insn per cycle # 0.14 stalled cycles per insn ( +- 0.00% ) 11,735,778,795 branches # 1302.453 M/sec ( +- 0.00% ) 98,084,459 branch-misses # 0.84% of all branches ( +- 0.28% ) 9.741247736 seconds time elapsed ( +- 0.07% ) ^^^^^^^^^^^ Link: http://lkml.kernel.org/r/20160806125608.GB1187@p183.telecom.by Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Andi Kleen <andi@firstfloor.org> 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>
2016-10-08fs/proc/task_mmu.c: make the task_mmu walk_page_range() limit in ↵James Morse
clear_refs_write() obvious Trying to walk all of virtual memory requires architecture specific knowledge. On x86_64, addresses must be sign extended from bit 48, whereas on arm64 the top VA_BITS of address space have their own set of page tables. clear_refs_write() calls walk_page_range() on the range 0 to ~0UL, it provides a test_walk() callback that only expects to be walking over VMAs. Currently walk_pmd_range() will skip memory regions that don't have a VMA, reporting them as a hole. As this call only expects to walk user address space, make it walk 0 to 'highest_vm_end'. Link: http://lkml.kernel.org/r/1472655792-22439-1-git-send-email-james.morse@arm.com Signed-off-by: James Morse <james.morse@arm.com> Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-06Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull namespace updates from Eric Biederman: "This set of changes is a number of smaller things that have been overlooked in other development cycles focused on more fundamental change. The devpts changes are small things that were a distraction until we managed to kill off DEVPTS_MULTPLE_INSTANCES. There is an trivial regression fix to autofs for the unprivileged mount changes that went in last cycle. A pair of ioctls has been added by Andrey Vagin making it is possible to discover the relationships between namespaces when referring to them through file descriptors. The big user visible change is starting to add simple resource limits to catch programs that misbehave. With namespaces in general and user namespaces in particular allowing users to use more kinds of resources, it has become important to have something to limit errant programs. Because the purpose of these limits is to catch errant programs the code needs to be inexpensive to use as it always on, and the default limits need to be high enough that well behaved programs on well behaved systems don't encounter them. To this end, after some review I have implemented per user per user namespace limits, and use them to limit the number of namespaces. The limits being per user mean that one user can not exhause the limits of another user. The limits being per user namespace allow contexts where the limit is 0 and security conscious folks can remove from their threat anlysis the code used to manage namespaces (as they have historically done as it root only). At the same time the limits being per user namespace allow other parts of the system to use namespaces. Namespaces are increasingly being used in application sand boxing scenarios so an all or nothing disable for the entire system for the security conscious folks makes increasing use of these sandboxes impossible. There is also added a limit on the maximum number of mounts present in a single mount namespace. It is nontrivial to guess what a reasonable system wide limit on the number of mount structure in the kernel would be, especially as it various based on how a system is using containers. A limit on the number of mounts in a mount namespace however is much easier to understand and set. In most cases in practice only about 1000 mounts are used. Given that some autofs scenarious have the potential to be 30,000 to 50,000 mounts I have set the default limit for the number of mounts at 100,000 which is well above every known set of users but low enough that the mount hash tables don't degrade unreaonsably. These limits are a start. I expect this estabilishes a pattern that other limits for resources that namespaces use will follow. There has been interest in making inotify event limits per user per user namespace as well as interest expressed in making details about what is going on in the kernel more visible" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (28 commits) autofs: Fix automounts by using current_real_cred()->uid mnt: Add a per mount namespace limit on the number of mounts netns: move {inc,dec}_net_namespaces into #ifdef nsfs: Simplify __ns_get_path tools/testing: add a test to check nsfs ioctl-s nsfs: add ioctl to get a parent namespace nsfs: add ioctl to get an owning user namespace for ns file descriptor kernel: add a helper to get an owning user namespace for a namespace devpts: Change the owner of /dev/pts/ptmx to the mounter of /dev/pts devpts: Remove sync_filesystems devpts: Make devpts_kill_sb safe if fsi is NULL devpts: Simplify devpts_mount by using mount_nodev devpts: Move the creation of /dev/pts/ptmx into fill_super devpts: Move parse_mount_options into fill_super userns: When the per user per user namespace limit is reached return ENOSPC userns; Document per user per user namespace limits. mntns: Add a limit on the number of mount namespaces. netns: Add a limit on the number of net namespaces cgroupns: Add a limit on the number of cgroup namespaces ipcns: Add a limit on the number of ipc namespaces ...
2016-10-05proc: switch auxv to use of __mem_open()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-10-05Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds
Pull networking updates from David Miller: 1) BBR TCP congestion control, from Neal Cardwell, Yuchung Cheng and co. at Google. https://lwn.net/Articles/701165/ 2) Do TCP Small Queues for retransmits, from Eric Dumazet. 3) Support collect_md mode for all IPV4 and IPV6 tunnels, from Alexei Starovoitov. 4) Allow cls_flower to classify packets in ip tunnels, from Amir Vadai. 5) Support DSA tagging in older mv88e6xxx switches, from Andrew Lunn. 6) Support GMAC protocol in iwlwifi mwm, from Ayala Beker. 7) Support ndo_poll_controller in mlx5, from Calvin Owens. 8) Move VRF processing to an output hook and allow l3mdev to be loopback, from David Ahern. 9) Support SOCK_DESTROY for UDP sockets. Also from David Ahern. 10) Congestion control in RXRPC, from David Howells. 11) Support geneve RX offload in ixgbe, from Emil Tantilov. 12) When hitting pressure for new incoming TCP data SKBs, perform a partial rathern than a full purge of the OFO queue (which could be huge). From Eric Dumazet. 13) Convert XFRM state and policy lookups to RCU, from Florian Westphal. 14) Support RX network flow classification to igb, from Gangfeng Huang. 15) Hardware offloading of eBPF in nfp driver, from Jakub Kicinski. 16) New skbmod packet action, from Jamal Hadi Salim. 17) Remove some inefficiencies in snmp proc output, from Jia He. 18) Add FIB notifications to properly propagate route changes to hardware which is doing forwarding offloading. From Jiri Pirko. 19) New dsa driver for qca8xxx chips, from John Crispin. 20) Implement RFC7559 ipv6 router solicitation backoff, from Maciej Żenczykowski. 21) Add L3 mode to ipvlan, from Mahesh Bandewar. 22) Support 802.1ad in mlx4, from Moshe Shemesh. 23) Support hardware LRO in mediatek driver, from Nelson Chang. 24) Add TC offloading to mlx5, from Or Gerlitz. 25) Convert various drivers to ethtool ksettings interfaces, from Philippe Reynes. 26) TX max rate limiting for cxgb4, from Rahul Lakkireddy. 27) NAPI support for ath10k, from Rajkumar Manoharan. 28) Support XDP in mlx5, from Rana Shahout and Saeed Mahameed. 29) UDP replicast support in TIPC, from Richard Alpe. 30) Per-queue statistics for qed driver, from Sudarsana Reddy Kalluru. 31) Support BQL in thunderx driver, from Sunil Goutham. 32) TSO support in alx driver, from Tobias Regnery. 33) Add stream parser engine and use it in kcm. 34) Support async DHCP replies in ipconfig module, from Uwe Kleine-König. 35) DSA port fast aging for mv88e6xxx driver, from Vivien Didelot. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1715 commits) mlxsw: switchx2: Fix misuse of hard_header_len mlxsw: spectrum: Fix misuse of hard_header_len net/faraday: Stop NCSI device on shutdown net/ncsi: Introduce ncsi_stop_dev() net/ncsi: Rework the channel monitoring net/ncsi: Allow to extend NCSI request properties net/ncsi: Rework request index allocation net/ncsi: Don't probe on the reserved channel ID (0x1f) net/ncsi: Introduce NCSI_RESERVED_CHANNEL net/ncsi: Avoid unused-value build warning from ia64-linux-gcc net: Add netdev all_adj_list refcnt propagation to fix panic net: phy: Add Edge-rate driver for Microsemi PHYs. vmxnet3: Wake queue from reset work i40e: avoid NULL pointer dereference and recursive errors on early PCI error qed: Add RoCE ll2 & GSI support qed: Add support for memory registeration verbs qed: Add support for QP verbs qed: PD,PKEY and CQ verb support qed: Add support for RoCE hw init qede: Add qedr framework ...
2016-09-30Merge branch 'x86/urgent' into x86/asmThomas Gleixner
Get the cr4 fixes so we can apply the final cleanup
2016-09-28fs: Replace CURRENT_TIME with current_time() for inode timestampsDeepa Dinamani
CURRENT_TIME macro is not appropriate for filesystems as it doesn't use the right granularity for filesystem timestamps. Use current_time() instead. CURRENT_TIME is also not y2038 safe. This is also in preparation for the patch that transitions vfs timestamps to use 64 bit time and hence make them y2038 safe. As part of the effort current_time() will be extended to do range checks. Hence, it is necessary for all file system timestamps to use current_time(). Also, current_time() will be transitioned along with vfs to be y2038 safe. Note that whenever a single call to current_time() is used to change timestamps in different inodes, it is because they share the same time granularity. Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Felipe Balbi <balbi@kernel.org> Acked-by: Steven Whitehouse <swhiteho@redhat.com> Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Acked-by: David Sterba <dsterba@suse.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-09-28fs: proc: Delete inode time initializations in proc_alloc_inode()Deepa Dinamani
proc uses new_inode_pseudo() to allocate a new inode. This in turn calls the proc_inode_alloc() callback. But, at this point, inode is still not initialized with the super_block pointer which only happens just before alloc_inode() returns after the call to inode_init_always(). Also, the inode times are initialized again after the call to new_inode_pseudo() in proc_inode_alloc(). The assignemet in proc_alloc_inode() is redundant and also doesn't work after the current_time() api is changed to take struct inode* instead of struct *super_block. This bug was reported after current_time() was used to assign times in proc_alloc_inode(). Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Reported-by: Fengguang Wu <fengguang.wu@intel.com> [0-day test robot] Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-09-27proc: unsigned file descriptorsAlexey Dobriyan
Make struct proc_inode::fd unsigned. This allows better code generation on x86_64 (less sign extensions). Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-09-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
2016-09-22fs: Give dentry to inode_change_ok() instead of inodeJan Kara
inode_change_ok() will be resposible for clearing capabilities and IMA extended attributes and as such will need dentry. Give it as an argument to inode_change_ok() instead of an inode. Also rename inode_change_ok() to setattr_prepare() to better relect that it does also some modifications in addition to checks. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
2016-09-20fs/proc/kcore.c: Add bounce buffer for ktext dataJiri Olsa
We hit hardened usercopy feature check for kernel text access by reading kcore file: usercopy: kernel memory exposure attempt detected from ffffffff8179a01f (<kernel text>) (4065 bytes) kernel BUG at mm/usercopy.c:75! Bypassing this check for kcore by adding bounce buffer for ktext data. Reported-by: Steve Best <sbest@redhat.com> Fixes: f5509cc18daa ("mm: Hardened usercopy") Suggested-by: Kees Cook <keescook@chromium.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-09-20fs/proc/kcore.c: Make bounce buffer global for readJiri Olsa
Next patch adds bounce buffer for ktext area, so it's convenient to have single bounce buffer for both vmalloc/module and ktext cases. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-09-15Merge branch 'linus' into x86/asm, to pick up recent fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-12Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Conflicts: drivers/net/ethernet/mediatek/mtk_eth_soc.c drivers/net/ethernet/qlogic/qed/qed_dcbx.c drivers/net/phy/Kconfig All conflicts were cases of overlapping commits. Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-10Merge branch 'libnvdimm-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm fixes from Dan Williams: "nvdimm fixes for v4.8, two of them are tagged for -stable: - Fix devm_memremap_pages() to use track_pfn_insert(). Otherwise, DAX pmd mappings end up with an uncached pgprot, and unusable performance for the device-dax interface. The device-dax interface appeared in 4.7 so this is tagged for -stable. - Fix a couple VM_BUG_ON() checks in the show_smaps() path to understand DAX pmd entries. This fix is tagged for -stable. - Fix a mis-merge of the nfit machine-check handler to flip the polarity of an if() to match the final version of the patch that Vishal sent for 4.8-rc1. Without this the nfit machine check handler never detects / inserts new 'badblocks' entries which applications use to identify lost portions of files. - For test purposes, fix the nvdimm_clear_poison() path to operate on legacy / simulated nvdimm memory ranges. Without this fix a test can set badblocks, but never clear them on these ranges. - Fix the range checking done by dax_dev_pmd_fault(). This is not tagged for -stable since this problem is mitigated by specifying aligned resources at device-dax setup time. These patches have appeared in a next release over the past week. The recent rebase you can see in the timestamps was to drop an invalid fix as identified by the updated device-dax unit tests [1]. The -mm touches have an ack from Andrew" [1]: "[ndctl PATCH 0/3] device-dax test for recent kernel bugs" https://lists.01.org/pipermail/linux-nvdimm/2016-September/006855.html * 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: libnvdimm: allow legacy (e820) pmem region to clear bad blocks nfit, mce: Fix SPA matching logic in MCE handler mm: fix cache mode of dax pmd mappings mm: fix show_smap() for zone_device-pmd ranges dax: fix mapping size check
2016-09-10mm: fix show_smap() for zone_device-pmd rangesDan Williams
Attempting to dump /proc/<pid>/smaps for a process with pmd dax mappings currently results in the following VM_BUG_ONs: kernel BUG at mm/huge_memory.c:1105! task: ffff88045f16b140 task.stack: ffff88045be14000 RIP: 0010:[<ffffffff81268f9b>] [<ffffffff81268f9b>] follow_trans_huge_pmd+0x2cb/0x340 [..] Call Trace: [<ffffffff81306030>] smaps_pte_range+0xa0/0x4b0 [<ffffffff814c2755>] ? vsnprintf+0x255/0x4c0 [<ffffffff8123c46e>] __walk_page_range+0x1fe/0x4d0 [<ffffffff8123c8a2>] walk_page_vma+0x62/0x80 [<ffffffff81307656>] show_smap+0xa6/0x2b0 kernel BUG at fs/proc/task_mmu.c:585! RIP: 0010:[<ffffffff81306469>] [<ffffffff81306469>] smaps_pte_range+0x499/0x4b0 Call Trace: [<ffffffff814c2795>] ? vsnprintf+0x255/0x4c0 [<ffffffff8123c46e>] __walk_page_range+0x1fe/0x4d0 [<ffffffff8123c8a2>] walk_page_vma+0x62/0x80 [<ffffffff81307696>] show_smap+0xa6/0x2b0 These locations are sanity checking page flags that must be set for an anonymous transparent huge page, but are not set for the zone_device pages associated with dax mappings. Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-09-01Merge branch 'stable-4.8' of git://git.infradead.org/users/pcmoore/auditLinus Torvalds
Pull audit fixes from Paul Moore: "Two small patches to fix some bugs with the audit-by-executable functionality we introduced back in v4.3 (both patches are marked for the stable folks)" * 'stable-4.8' of git://git.infradead.org/users/pcmoore/audit: audit: fix exe_file access in audit_exe_compare mm: introduce get_task_exe_file
2016-08-31mm: introduce get_task_exe_fileMateusz Guzik
For more convenient access if one has a pointer to the task. As a minor nit take advantage of the fact that only task lock + rcu are needed to safely grab ->exe_file. This saves mm refcount dance. Use the helper in proc_exe_link. Signed-off-by: Mateusz Guzik <mguzik@redhat.com> Acked-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Acked-by: Richard Guy Briggs <rgb@redhat.com> Cc: <stable@vger.kernel.org> # 4.3.x Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-08-18proc: Fix return address printk conversion specifer in /proc/<pid>/stackJosh Poimboeuf
When printing call return addresses found on a stack, /proc/<pid>/stack can sometimes give a confusing result. If the call instruction was the last instruction in the function (which can happen when calling a noreturn function), '%pS' will incorrectly display the name of the function which happens to be next in the object code, rather than the name of the actual calling function. Use '%pB' instead, which was created for this exact purpose. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Byungchul Park <byungchul.park@lge.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nilay Vaish <nilayvaish@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/47ad2821e5ebdbed1fbf83fb85424ae4fbdf8b6e.1471535549.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-18Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Minor overlapping changes for both merge conflicts. Resolution work done by Stephen Rothwell was used as a reference. Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15net: make net namespace sysctls belong to container's ownerDmitry Torokhov
If net namespace is attached to a user namespace let's make container's root owner of sysctls affecting said network namespace instead of global root. This also allows us to clean up net_ctl_permissions() because we do not need to fudge permissions anymore for the container's owner since it now owns the objects in question. Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15proc: make proc entries inherit ownership from parentDmitry Torokhov
There are certain parameters that belong to net namespace and that are exported in /proc. They should be controllable by the container's owner, but are currently owned by global root and thus not available. Let's change proc code to inherit ownership of parent entry, and when create per-ns "net" proc entry set it up as owned by container's owner. Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-11proc, meminfo: use correct helpers for calculating LRU sizes in meminfoMel Gorman
meminfo_proc_show() and si_mem_available() are using the wrong helpers for calculating the size of the LRUs. The user-visible impact is that there appears to be an abnormally high number of unevictable pages. Link: http://lkml.kernel.org/r/20160805105805.GR2799@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Cc: Dave Chinner <david@fromorbit.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-08sysctl: Stop implicitly passing current into sysctl_table_root.lookupEric W. Biederman
Passing nsproxy into sysctl_table_root.lookup was a premature optimization in attempt to avoid depending on current. The directory /proc/self/sys has not appeared and if and when it does this code will need to be reviewed closely and reworked anyway. So remove the premature optimization. Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Serge Hallyn <serge@hallyn.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2016-08-07Merge branch 'for-linus-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull more vfs updates from Al Viro: "Assorted cleanups and fixes. In the "trivial API change" department - ->d_compare() losing 'parent' argument" * 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: cachefiles: Fix race between inactivating and culling a cache object 9p: use clone_fid() 9p: fix braino introduced in "9p: new helper - v9fs_parent_fid()" vfs: make dentry_needs_remove_privs() internal vfs: remove file_needs_remove_privs() vfs: fix deadlock in file_remove_privs() on overlayfs get rid of 'parent' argument of ->d_compare() cifs, msdos, vfat, hfs+: don't bother with parent in ->d_compare() affs ->d_compare(): don't bother with ->d_inode fold _d_rehash() and __d_rehash() together fold dentry_rcuwalk_invalidate() into its only remaining caller
2016-08-06Merge branch 'work.const-qstr' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull qstr constification updates from Al Viro: "Fairly self-contained bunch - surprising lot of places passes struct qstr * as an argument when const struct qstr * would suffice; it complicates analysis for no good reason. I'd prefer to feed that separately from the assorted fixes (those are in #for-linus and with somewhat trickier topology)" * 'work.const-qstr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: qstr: constify instances in adfs qstr: constify instances in lustre qstr: constify instances in f2fs qstr: constify instances in ext2 qstr: constify instances in vfat qstr: constify instances in procfs qstr: constify instances in fuse qstr constify instances in fs/dcache.c qstr: constify instances in nfs qstr: constify instances in ocfs2 qstr: constify instances in autofs4 qstr: constify instances in hfs qstr: constify instances in hfsplus qstr: constify instances in logfs qstr: constify dentry_init_security
2016-08-03fs/proc: Add compiler check for -Wno-override-init to support gcc < 4.2Geert Uytterhoeven
With gcc < 4.2 (e.g. 4.1.2): CC fs/proc/task_mmu.o cc1: error: unrecognized command line option "-Wno-override-init" To fix this, only enable the compiler option when it is actually supported by the compiler. Fixes: ca52953f5f24 ("fs/proc/task_mmu.c: suppress compilation warnings with W=1") Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Valdis Kletnieks <valdis.kletnieks@vt.edu> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02fs/proc/task_mmu.c: suppress compilation warnings with W=1Valdis Kletnieks
Suppress a bunch of warnings of the form: fs/proc/task_mmu.c: In function 'show_smap_vma_flags': fs/proc/task_mmu.c:635:22: warning: initialized field overwritten [-Wt override-init] [ilog2(VM_READ)] = "rd", ^~~~ fs/proc/task_mmu.c:635:22: note: (near initialization for 'mnemonics[0]') They happen because of the way we intentionally build the table, so silence the warning when building with 'make W=1'. Link: http://lkml.kernel.org/r/8727.1470022083@turing-police.cc.vt.edu Signed-off-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>
2016-08-02procfs: avoid 32-bit time_t in /proc/*/statArnd Bergmann
/proc/stat shows (among lots of other things) the current boottime (i.e. number of seconds since boot). While a 32-bit number is sufficient for this particular case, we want to get rid of the 'struct timespec' suffers from a 32-bit overflow in 2038. This changes the code to use a struct timespec64, which is known to be safe in all cases. Link: http://lkml.kernel.org/r/20160617201247.2292101-1-arnd@arndb.de Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02proc_oom_score: remove tasklist_lock and pid_alive()Oleg Nesterov
This was needed before to ensure that ->signal != 0 and do_each_thread() is safe, see commit b95c35e76b29b ("oom: fix the unsafe usage of badness() in proc_oom_score()") for details. Today tsk->signal can't go away and for_each_thread(tsk) is always safe. Link: http://lkml.kernel.org/r/20160608211921.GA15508@redhat.com Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-31get rid of 'parent' argument of ->d_compare()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>