user/sven/linux.git/fs/open.c, branch v4.4.27

vfs: add vfs_select_inode() helper

2016-05-19T00:06:48Z

commit 54d5ca871e72f2bb172ec9323497f01cd5091ec7 upstream. Signed-off-by: Miklos Szeredi Signed-off-by: Greg Kroah-Hartman

fs/coredump: prevent fsuid=0 dumps into user-controlled directories

2016-04-12T16:08:58Z

commit 378c6520e7d29280f400ef2ceaf155c86f05a71a upstream. This commit fixes the following security hole affecting systems where all of the following conditions are fulfilled: - The fs.suid_dumpable sysctl is set to 2. - The kernel.core_pattern sysctl's value starts with "/". (Systems where kernel.core_pattern starts with "|/" are not affected.) - Unprivileged user namespace creation is permitted. (This is true on Linux >=3.8, but some distributions disallow it by default using a distro patch.) Under these conditions, if a program executes under secure exec rules, causing it to run with the SUID_DUMP_ROOT flag, then unshares its user namespace, changes its root directory and crashes, the coredump will be written using fsuid=0 and a path derived from kernel.core_pattern - but this path is interpreted relative to the root directory of the process, allowing the attacker to control where a coredump will be written with root privileges. To fix the security issue, always interpret core_pattern for dumps that are written under SUID_DUMP_ROOT relative to the root directory of init. Signed-off-by: Jann Horn Acked-by: Kees Cook Cc: Al Viro Cc: "Eric W. Biederman" Cc: Andy Lutomirski Cc: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

vfs: Commit to never having exectuables on proc and sysfs.

2015-07-10T15:39:25Z

Today proc and sysfs do not contain any executable files. Several applications today mount proc or sysfs without noexec and nosuid and then depend on there being no exectuables files on proc or sysfs. Having any executable files show on proc or sysfs would cause a user space visible regression, and most likely security problems. Therefore commit to never allowing executables on proc and sysfs by adding a new flag to mark them as filesystems without executables and enforce that flag. Test the flag where MNT_NOEXEC is tested today, so that the only user visible effect will be that exectuables will be treated as if the execute bit is cleared. The filesystems proc and sysfs do not currently incoporate any executable files so this does not result in any user visible effects. This makes it unnecessary to vet changes to proc and sysfs tightly for adding exectuable files or changes to chattr that would modify existing files, as no matter what the individual file say they will not be treated as exectuable files by the vfs. Not having to vet changes to closely is important as without this we are only one proc_create call (or another goof up in the implementation of notify_change) from having problematic executables on proc. Those mistakes are all too easy to make and would create a situation where there are security issues or the assumptions of some program having to be broken (and cause userspace regressions). Signed-off-by: "Eric W. Biederman"

fs: Call security_ops->inode_killpriv on truncate

2015-06-23T22:01:09Z

Comment in include/linux/security.h says that ->inode_killpriv() should be called when setuid bit is being removed and that similar security labels (in fact this applies only to file capabilities) should be removed at this time as well. However we don't call ->inode_killpriv() when we remove suid bit on truncate. We fix the problem by calling ->inode_need_killpriv() and subsequently ->inode_killpriv() on truncate the same way as we do it on file write. After this patch there's only one user of should_remove_suid() - ocfs2 - and indeed it's buggy because it doesn't call ->inode_killpriv() on write. However fixing it is difficult because of special locking constraints. Signed-off-by: Jan Kara Signed-off-by: Al Viro

vfs: add file_path() helper

2015-06-23T22:00:05Z

Turn d_path(&file->f_path, ...); into file_path(file, ...); Signed-off-by: Miklos Szeredi Signed-off-by: Al Viro

overlayfs: Make f_path always point to the overlay and f_inode to the underlay

2015-06-19T07:19:32Z

Make file->f_path always point to the overlay dentry so that the path in /proc/pid/fd is correct and to ensure that label-based LSMs have access to the overlay as well as the underlay (path-based LSMs probably don't need it). Using my union testsuite to set things up, before the patch I see: [root@andromeda union-testsuite]# bash 5 /a/foo107 [root@andromeda union-testsuite]# stat /mnt/a/foo107 ... Device: 23h/35d Inode: 13381 Links: 1 ... [root@andromeda union-testsuite]# stat -L /proc/$$/fd/5 ... Device: 23h/35d Inode: 13381 Links: 1 ... After the patch: [root@andromeda union-testsuite]# bash 5 /mnt/a/foo107 [root@andromeda union-testsuite]# stat /mnt/a/foo107 ... Device: 23h/35d Inode: 40346 Links: 1 ... [root@andromeda union-testsuite]# stat -L /proc/$$/fd/5 ... Device: 23h/35d Inode: 40346 Links: 1 ... Note the change in where /proc/$$/fd/5 points to in the ls command. It was pointing to /a/foo107 (which doesn't exist) and now points to /mnt/a/foo107 (which is correct). The inode accessed, however, is the lower layer. The union layer is on device 25h/37d and the upper layer on 24h/36d. Signed-off-by: David Howells Signed-off-by: Al Viro

VFS: Handle lower layer dentry/inode in pathwalk

2015-05-11T12:13:10Z

Make use of d_backing_inode() in pathwalk to gain access to an inode or dentry that's on a lower layer. Signed-off-by: David Howells

Merge tag 'xfs-for-linus-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs

2015-04-24T14:08:41Z

Pull xfs update from Dave Chinner: "This update contains: - RENAME_WHITEOUT support - conversion of per-cpu superblock accounting to use generic counters - new inode mmap lock so that we can lock page faults out of truncate, hole punch and other direct extent manipulation functions to avoid racing mmap writes from causing data corruption - rework of direct IO submission and completion to solve data corruption issue when running concurrent extending DIO writes. Also solves problem of running IO completion transactions in interrupt context during size extending AIO writes. - FALLOC_FL_INSERT_RANGE support for inserting holes into a file via direct extent manipulation to avoid needing to copy data within the file - attribute block header field overflow fix for 64k block size filesystems - Lots of changes to log messaging to be more informative and concise when errors occur. Also prevent a lot of unnecessary log spamming due to cascading failures in error conditions. - lots of cleanups and bug fixes One thing of note is the direct IO fixes that we merged last week after the window opened. Even though a little late, they fix a user reported data corruption and have been pretty well tested. I figured there was not much point waiting another 2 weeks for -rc1 to be released just so I could send them to you..." * tag 'xfs-for-linus-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs: (49 commits) xfs: using generic_file_direct_write() is unnecessary xfs: direct IO EOF zeroing needs to drain AIO xfs: DIO write completion size updates race xfs: DIO writes within EOF don't need an ioend xfs: handle DIO overwrite EOF update completion correctly xfs: DIO needs an ioend for writes xfs: move DIO mapping size calculation xfs: factor DIO write mapping from get_blocks xfs: unlock i_mutex in xfs_break_layouts xfs: kill unnecessary firstused overflow check on attr3 leaf removal xfs: use larger in-core attr firstused field and detect overflow xfs: pass attr geometry to attr leaf header conversion functions xfs: disallow ro->rw remount on norecovery mount xfs: xfs_shift_file_space can be static xfs: Add support FALLOC_FL_INSERT_RANGE for fallocate fs: Add support FALLOC_FL_INSERT_RANGE for fallocate xfs: Fix incorrect positive ENOMEM return xfs: xfs_mru_cache_insert() should use GFP_NOFS xfs: %pF is only for function pointers xfs: fix shadow warning in xfs_da3_root_split() ...

->aio_read and ->aio_write removed

2015-04-12T02:29:43Z

no remaining users Signed-off-by: Al Viro

NFS: fix BUG() crash in notify_change() with patch to chown_common()

2015-04-12T02:24:34Z

We have observed a BUG() crash in fs/attr.c:notify_change(). The crash occurs during an rsync into a filesystem that is exported via NFS. 1.) fs/attr.c:notify_change() modifies the caller's version of attr. 2.) 6de0ec00ba8d ("VFS: make notify_change pass ATTR_KILL_S*ID to setattr operations") introduced a BUG() restriction such that "no function will ever call notify_change() with both ATTR_MODE and ATTR_KILL_S*ID set". Under some circumstances though, it will have assisted in setting the caller's version of attr to this very combination. 3.) 27ac0ffeac80 ("locks: break delegations on any attribute modification") introduced code to handle breaking delegations. This can result in notify_change() being re-called. attr _must_ be explicitly reset to avoid triggering the BUG() established in #2. 4.) The path that that triggers this is via fs/open.c:chmod_common(). The combination of attr flags set here and in the first call to notify_change() along with a later failed break_deleg_wait() results in notify_change() being called again via retry_deleg without resetting attr. Solution is to move retry_deleg in chmod_common() a bit further up to ensure attr is completely reset. There are other places where this seemingly could occur, such as fs/utimes.c:utimes_common(), but the attr flags are not initially set in such a way to trigger this. Fixes: 27ac0ffeac80 ("locks: break delegations on any attribute modification") Reported-by: Eric Meddaugh Tested-by: Eric Meddaugh Signed-off-by: Andrew Elble Signed-off-by: Al Viro