user/sven/linux.git/fs/proc, branch v4.9.12

sysctl: Drop reference added by grab_header in proc_sys_readdir

2017-01-19T19:18:04Z

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] [] schedule+0x3f/0xa0 [ 5535.968817] [] schedule_timeout+0x3db/0x6f0 [ 5535.975346] [] ? wait_for_completion+0x45/0x130 [ 5535.982256] [] wait_for_completion+0xc3/0x130 [ 5535.988972] [] ? wake_up_q+0x80/0x80 [ 5535.994804] [] drop_sysctl_table+0xc4/0xe0 [ 5536.001227] [] drop_sysctl_table+0x77/0xe0 [ 5536.007648] [] unregister_sysctl_table+0x4d/0xa0 [ 5536.014654] [] unregister_sysctl_table+0x7f/0xa0 [ 5536.021657] [] unregister_sched_domain_sysctl+0x15/0x40 [ 5536.029344] [] partition_sched_domains+0x44/0x450 [ 5536.036447] [] ? __mutex_unlock_slowpath+0x111/0x1f0 [ 5536.043844] [] rebuild_sched_domains_locked+0x64/0xb0 [ 5536.051336] [] update_flag+0x11d/0x210 [ 5536.057373] [] ? mutex_lock_nested+0x2df/0x450 [ 5536.064186] [] ? cpuset_css_offline+0x1b/0x60 [ 5536.070899] [] ? trace_hardirqs_on+0xd/0x10 [ 5536.077420] [] ? mutex_lock_nested+0x2df/0x450 [ 5536.084234] [] ? css_killed_work_fn+0x25/0x220 [ 5536.091049] [] cpuset_css_offline+0x35/0x60 [ 5536.097571] [] css_killed_work_fn+0x5c/0x220 [ 5536.104207] [] process_one_work+0x1df/0x710 [ 5536.110736] [] ? process_one_work+0x160/0x710 [ 5536.117461] [] worker_thread+0x12b/0x4a0 [ 5536.123697] [] ? process_one_work+0x710/0x710 [ 5536.130426] [] kthread+0xfe/0x120 [ 5536.135991] [] ret_from_fork+0x1f/0x40 [ 5536.142041] [] ? 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 Tested-by: Yang Shukui Signed-off-by: Zhou Chengming Acked-by: Al Viro Signed-off-by: Eric W. Biederman Signed-off-by: Greg Kroah-Hartman

proc: fix NULL dereference when reading /proc//auxv

2016-10-28T01:43:43Z

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 Acked-by: Oleg Nesterov Acked-by: Michal Hocko Cc: Al Viro Cc: Kees Cook Cc: John Stultz Cc: Mateusz Guzik Cc: Janis Danisevskis Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

proc: don't use FOLL_FORCE for reading cmdline and environment

2016-10-25T02:00:44Z

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

Merge branch 'mm-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2016-10-22T16:39:10Z

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

fs/proc: Stop trying to report thread stacks

2016-10-20T07:21:41Z

This reverts more of: b76437579d13 ("procfs: mark thread stack correctly in proc//maps") ... which was partially reverted by: 65376df58217 ("proc: revert /proc//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 Signed-off-by: Andy Lutomirski Acked-by: Thomas Gleixner Cc: Al Viro Cc: Andrew Morton Cc: Borislav Petkov Cc: Brian Gerst Cc: Johannes Weiner Cc: Kees Cook Cc: Linus Torvalds Cc: Linux API Cc: Peter Zijlstra Cc: Tycho Andersen Link: http://lkml.kernel.org/r/3e678474ec14e0a0ec34c611016753eea2e1b8ba.1475257877.git.luto@kernel.org Signed-off-by: Ingo Molnar

fs/proc: Stop reporting eip and esp in /proc/PID/stat

2016-10-20T07:21:41Z

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 Signed-off-by: Andy Lutomirski Acked-by: Thomas Gleixner Cc: Al Viro Cc: Andrew Morton Cc: Borislav Petkov Cc: Brian Gerst Cc: Kees Cook Cc: Linus Torvalds Cc: Linux API Cc: Peter Zijlstra Cc: Tetsuo Handa Cc: Tycho Andersen Link: http://lkml.kernel.org/r/a5fed4c3f4e33ed25d4bb03567e329bc5a712bcc.1475257877.git.luto@kernel.org Signed-off-by: Ingo Molnar

mm: replace access_remote_vm() write parameter with gup_flags

2016-10-19T15:12:14Z

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 Acked-by: Michal Hocko Signed-off-by: Linus Torvalds

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2016-10-11T03:16:43Z

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

Merge remote-tracking branch 'ovl/rename2' into for-linus

2016-10-11T03:02:51Z

Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2016-10-10T20:04:49Z

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() ...