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path: root/fs/namei.c
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2018-07-12IMA: don't propagate opened through the entire thingAl Viro
just check ->f_mode in ima_appraise_measurement() Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12introduce FMODE_CREATED and switch to itAl Viro
Parallel to FILE_CREATED, goes into ->f_mode instead of *opened. NFS is a bit of a wart here - it doesn't have file at the point where FILE_CREATED used to be set, so we need to propagate it there (for now). IMA is another one (here and everywhere)... Note that this needs do_dentry_open() to leave old bits in ->f_mode alone - we want it to preserve FMODE_CREATED if it had been already set (no other bit can be there). Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12switch all remaining checks for FILE_OPENED to FMODE_OPENEDAl Viro
... and don't bother with setting FILE_OPENED at all. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12now we can fold open_check_o_direct() into do_dentry_open()Al Viro
These checks are better off in do_dentry_open(); the reason we couldn't put them there used to be that callers couldn't tell what kind of cleanup would do_dentry_open() failure call for. Now that we have FMODE_OPENED, cleanup is the same in all cases - it's simply fput(). So let's fold that into do_dentry_open(), as Christoph's patch tried to. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12lift fput() on late failures into path_openat()Al Viro
Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12fold put_filp() into fput()Al Viro
Just check FMODE_OPENED in __fput() and be done with that... Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12get rid of cred argument of vfs_open() and do_dentry_open()Al Viro
always equal to ->f_cred Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12pass ->f_flags value to alloc_empty_file()Al Viro
... and have it set the f_flags-derived part of ->f_mode. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12pass creds to get_empty_filp(), make sure dentry_open() passes the right credsAl Viro
... and rename get_empty_filp() to alloc_empty_file(). dentry_open() gets creds as argument, but the only thing that sees those is security_file_open() - file->f_cred still ends up with current_cred(). For almost all callers it's the same thing, but there are several broken cases. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-06-16Merge branch 'afs-proc' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull AFS updates from Al Viro: "Assorted AFS stuff - ended up in vfs.git since most of that consists of David's AFS-related followups to Christoph's procfs series" * 'afs-proc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: afs: Optimise callback breaking by not repeating volume lookup afs: Display manually added cells in dynamic root mount afs: Enable IPv6 DNS lookups afs: Show all of a server's addresses in /proc/fs/afs/servers afs: Handle CONFIG_PROC_FS=n proc: Make inline name size calculation automatic afs: Implement network namespacing afs: Mark afs_net::ws_cell as __rcu and set using rcu functions afs: Fix a Sparse warning in xdr_decode_AFSFetchStatus() proc: Add a way to make network proc files writable afs: Rearrange fs/afs/proc.c to remove remaining predeclarations. afs: Rearrange fs/afs/proc.c to move the show routines up afs: Rearrange fs/afs/proc.c by moving fops and open functions down afs: Move /proc management functions to the end of the file
2018-06-15afs: Display manually added cells in dynamic root mountDavid Howells
Alter the dynroot mount so that cells created by manipulation of /proc/fs/afs/cells and /proc/fs/afs/rootcell and by specification of a root cell as a module parameter will cause directories for those cells to be created in the dynamic root superblock for the network namespace[*]. To this end: (1) Only one dynamic root superblock is now created per network namespace and this is shared between all attempts to mount it. This makes it easier to find the superblock to modify. (2) When a dynamic root superblock is created, the list of cells is walked and directories created for each cell already defined. (3) When a new cell is added, if a dynamic root superblock exists, a directory is created for it. (4) When a cell is destroyed, the directory is removed. (5) These directories are created by calling lookup_one_len() on the root dir which automatically creates them if they don't exist. [*] Inasmuch as network namespaces are currently supported here. Signed-off-by: David Howells <dhowells@redhat.com>
2018-06-12treewide: kmalloc() -> kmalloc_array()Kees Cook
The kmalloc() function has a 2-factor argument form, kmalloc_array(). This patch replaces cases of: kmalloc(a * b, gfp) with: kmalloc_array(a * b, gfp) as well as handling cases of: kmalloc(a * b * c, gfp) with: kmalloc(array3_size(a, b, c), gfp) as it's slightly less ugly than: kmalloc_array(array_size(a, b), c, gfp) This does, however, attempt to ignore constant size factors like: kmalloc(4 * 1024, gfp) though any constants defined via macros get caught up in the conversion. Any factors with a sizeof() of "unsigned char", "char", and "u8" were dropped, since they're redundant. The tools/ directory was manually excluded, since it has its own implementation of kmalloc(). The Coccinelle script used for this was: // Fix redundant parens around sizeof(). @@ type TYPE; expression THING, E; @@ ( kmalloc( - (sizeof(TYPE)) * E + sizeof(TYPE) * E , ...) | kmalloc( - (sizeof(THING)) * E + sizeof(THING) * E , ...) ) // Drop single-byte sizes and redundant parens. @@ expression COUNT; typedef u8; typedef __u8; @@ ( kmalloc( - sizeof(u8) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(__u8) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(char) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(unsigned char) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(u8) * COUNT + COUNT , ...) | kmalloc( - sizeof(__u8) * COUNT + COUNT , ...) | kmalloc( - sizeof(char) * COUNT + COUNT , ...) | kmalloc( - sizeof(unsigned char) * COUNT + COUNT , ...) ) // 2-factor product with sizeof(type/expression) and identifier or constant. @@ type TYPE; expression THING; identifier COUNT_ID; constant COUNT_CONST; @@ ( - kmalloc + kmalloc_array ( - sizeof(TYPE) * (COUNT_ID) + COUNT_ID, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * COUNT_ID + COUNT_ID, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * (COUNT_CONST) + COUNT_CONST, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * COUNT_CONST + COUNT_CONST, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (COUNT_ID) + COUNT_ID, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * COUNT_ID + COUNT_ID, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (COUNT_CONST) + COUNT_CONST, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * COUNT_CONST + COUNT_CONST, sizeof(THING) , ...) ) // 2-factor product, only identifiers. @@ identifier SIZE, COUNT; @@ - kmalloc + kmalloc_array ( - SIZE * COUNT + COUNT, SIZE , ...) // 3-factor product with 1 sizeof(type) or sizeof(expression), with // redundant parens removed. @@ expression THING; identifier STRIDE, COUNT; type TYPE; @@ ( kmalloc( - sizeof(TYPE) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(THING) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) ) // 3-factor product with 2 sizeof(variable), with redundant parens removed. @@ expression THING1, THING2; identifier COUNT; type TYPE1, TYPE2; @@ ( kmalloc( - sizeof(TYPE1) * sizeof(TYPE2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kmalloc( - sizeof(THING1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kmalloc( - sizeof(THING1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) ) // 3-factor product, only identifiers, with redundant parens removed. @@ identifier STRIDE, SIZE, COUNT; @@ ( kmalloc( - (COUNT) * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) ) // Any remaining multi-factor products, first at least 3-factor products, // when they're not all constants... @@ expression E1, E2, E3; constant C1, C2, C3; @@ ( kmalloc(C1 * C2 * C3, ...) | kmalloc( - (E1) * E2 * E3 + array3_size(E1, E2, E3) , ...) | kmalloc( - (E1) * (E2) * E3 + array3_size(E1, E2, E3) , ...) | kmalloc( - (E1) * (E2) * (E3) + array3_size(E1, E2, E3) , ...) | kmalloc( - E1 * E2 * E3 + array3_size(E1, E2, E3) , ...) ) // And then all remaining 2 factors products when they're not all constants, // keeping sizeof() as the second factor argument. @@ expression THING, E1, E2; type TYPE; constant C1, C2, C3; @@ ( kmalloc(sizeof(THING) * C2, ...) | kmalloc(sizeof(TYPE) * C2, ...) | kmalloc(C1 * C2 * C3, ...) | kmalloc(C1 * C2, ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * (E2) + E2, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * E2 + E2, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (E2) + E2, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * E2 + E2, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - (E1) * E2 + E1, E2 , ...) | - kmalloc + kmalloc_array ( - (E1) * (E2) + E1, E2 , ...) | - kmalloc + kmalloc_array ( - E1 * E2 + E1, E2 , ...) ) Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-04Merge branch 'userns-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull userns updates from Eric Biederman: "This is the last couple of vfs bits to enable root in a user namespace to mount and manipulate a filesystem with backing store (AKA not a virtual filesystem like proc, but a filesystem where the unprivileged user controls the content). The target filesystem for this work is fuse, and Miklos should be sending you the pull request for the fuse bits this merge window. The two key patches are "evm: Don't update hmacs in user ns mounts" and "vfs: Don't allow changing the link count of an inode with an invalid uid or gid". Those close small gaps in the vfs that would be a problem if an unprivileged fuse filesystem is mounted. The rest of the changes are things that are now safe to allow a root user in a user namespace to do with a filesystem they have mounted. The most interesting development is that remount is now safe" * 'userns-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: fs: Allow CAP_SYS_ADMIN in s_user_ns to freeze and thaw filesystems capabilities: Allow privileged user in s_user_ns to set security.* xattrs fs: Allow superblock owner to access do_remount_sb() fs: Allow superblock owner to replace invalid owners of inodes vfs: Allow userns root to call mknod on owned filesystems. vfs: Don't allow changing the link count of an inode with an invalid uid or gid evm: Don't update hmacs in user ns mounts
2018-06-04Merge branch 'work.misc' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull misc vfs updates from Al Viro: "Misc bits and pieces not fitting into anything more specific" * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: vfs: delete unnecessary assignment in vfs_listxattr Documentation: filesystems: update filesystem locking documentation vfs: namei: use path_equal() in follow_dotdot() fs.h: fix outdated comment about file flags __inode_security_revalidate() never gets NULL opt_dentry make xattr_getsecurity() static vfat: simplify checks in vfat_lookup() get rid of dead code in d_find_alias() it's SB_BORN, not MS_BORN... msdos_rmdir(): kill BS comment remove rpc_rmdir() fs: avoid fdput() after failed fdget() in vfs_dedupe_file_range()
2018-06-04Merge branch 'work.rmdir' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull rmdir update from Al Viro: "More shrink_dcache_parent()-related stuff - killing the main source of potentially contended calls of that on large subtrees" * 'work.rmdir' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: rmdir(),rename(): do shrink_dcache_parent() only on success
2018-06-03Revert "fs: fold open_check_o_direct into do_dentry_open"Al Viro
This reverts commit cab64df194667dc5d9d786f0a895f647f5501c0d. Having vfs_open() in some cases drop the reference to struct file combined with error = vfs_open(path, f, cred); if (error) { put_filp(f); return ERR_PTR(error); } return f; is flat-out wrong. It used to be error = vfs_open(path, f, cred); if (!error) { /* from now on we need fput() to dispose of f */ error = open_check_o_direct(f); if (error) { fput(f); f = ERR_PTR(error); } } else { put_filp(f); f = ERR_PTR(error); } and sure, having that open_check_o_direct() boilerplate gotten rid of is nice, but not that way... Worse, another call chain (via finish_open()) is FUBAR now wrt FILE_OPENED handling - in that case we get error returned, with file already hit by fput() *AND* FILE_OPENED not set. Guess what happens in path_openat(), when it hits if (!(opened & FILE_OPENED)) { BUG_ON(!error); put_filp(file); } The root cause of all that crap is that the callers of do_dentry_open() have no way to tell which way did it fail; while that could be fixed up (by passing something like int *opened to do_dentry_open() and have it marked if we'd called ->open()), it's probably much too late in the cycle to do so right now. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-05-27rmdir(),rename(): do shrink_dcache_parent() only on successAl Viro
Once upon a time ->rmdir() instances used to check if victim inode had more than one (in-core) reference and failed with -EBUSY if it had. The reason was race avoidance - emptiness check is worthless if somebody could just go and create new objects in the victim directory afterwards. With introduction of dcache the checks had been replaced with checking the refcount of dentry. However, since a cached negative lookup leaves a negative child dentry, such check had lead to false positives - with empty foo/ doing stat foo/bar before rmdir foo ended up with -EBUSY unless the negative dentry of foo/bar happened to be evicted by the time of rmdir(2). That had been fixed by doing shrink_dcache_parent() just before the refcount check. At the same time, ext2_rmdir() has grown a private solution that eliminated those -EBUSY - it did something (setting ->i_size to 0) which made any subsequent ext2_add_entry() fail. Unfortunately, even with shrink_dcache_parent() the check had been racy - after all, the victim itself could be found by dcache lookup just after we'd checked its refcount. That got fixed by a new helper (dentry_unhash()) that did shrink_dcache_parent() and unhashed the sucker if its refcount ended up equal to 1. That got called before ->rmdir(), turning the checks in ->rmdir() instances into "if not unhashed fail with -EBUSY". Which reduced the boilerplate nicely, but had an unpleasant side effect - now shrink_dcache_parent() had been done before the emptiness checks, leading to easily triggerable calls of shrink_dcache_parent() on arbitrary large subtrees, quite possibly nested into each other. Several years later the ext2-private trick had been generalized - (in-core) inodes of dead directories are flagged and calls of lookup, readdir and all directory-modifying methods were prevented in so marked directories. Remaining boilerplate in ->rmdir() instances became redundant and some instances got rid of it. In 2011 the call of dentry_unhash() got shifted into ->rmdir() instances and then killed off in all of them. That has lead to another problem, though - in case of successful rmdir we *want* any (negative) child dentries dropped and the victim itself made negative. There's no point keeping cached negative lookups in foo when we can get the negative lookup of foo itself cached. So shrink_dcache_parent() call had been restored; unfortunately, it went into the place where dentry_unhash() used to be, i.e. before the ->rmdir() call. Note that we don't unhash anymore, so any "is it busy" checks would be racy; fortunately, all of them are gone. We should've done that call right *after* successful ->rmdir(). That reduces contention caused by tree-walking in shrink_dcache_parent() and, especially, contention caused by evictions in two nested subtrees going on in parallel. The same goes for directory-overwriting rename() - the story there had been parallel to that of rmdir(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-05-24vfs: Allow userns root to call mknod on owned filesystems.Eric W. Biederman
These filesystems already always set SB_I_NODEV so mknod will not be useful for gaining control of any devices no matter their permissions. This will allow overlayfs and applications like to fakeroot to use device nodes to represent things on disk. Acked-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-05-24vfs: Don't allow changing the link count of an inode with an invalid uid or gidEric W. Biederman
Changing the link count of an inode via unlink or link will cause a write back of that inode. If the uids or gids are invalid (aka not known to the kernel) writing the inode back may change the uid or gid in the filesystem. To prevent possible filesystem and to avoid the need for filesystem maintainers to worry about it don't allow operations on inodes with an invalid uid or gid. Acked-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-05-17vfs: namei: use path_equal() in follow_dotdot()Danilo Krummrich
Use path_equal() to detect whether we're already in root. Signed-off-by: Danilo Krummrich <danilokrummrich@dk-develop.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-04-09Merge branch 'work.namei' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs namei updates from Al Viro: - make lookup_one_len() safe with parent locked only shared(incoming afs series wants that) - fix of getname_kernel() regression from 2015 (-stable fodder, that one). * 'work.namei' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: getname_kernel() needs to make sure that ->name != ->iname in long case make lookup_one_len() safe to use with directory locked shared new helper: __lookup_slow() merge common parts of lookup_one_len{,_unlocked} into common helper
2018-04-08getname_kernel() needs to make sure that ->name != ->iname in long caseAl Viro
missed it in "kill struct filename.separate" several years ago. Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-04-06Merge tag 'audit-pr-20180403' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit Pull audit updates from Paul Moore: "We didn't have anything to send for v4.16, but we're back with a little more than usual for v4.17. Eleven patches in total, most fall into the small fix category, but there are three non-trivial changes worth calling out: - the audit entry filter is being removed after deprecating it for quite a while (years of no one really using it because it turns out to be not very practical) - created our own version of "__mutex_owner()" because the locking folks were upset we were using theirs - improved our handling of kernel command line parameters to make them more forgiving - we fixed auditing of symlink operations Everything passes the audit-testsuite and as of a few minutes ago it merges well with your tree" * tag 'audit-pr-20180403' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit: audit: add refused symlink to audit_names audit: remove path param from link denied function audit: link denied should not directly generate PATH record audit: make ANOM_LINK obey audit_enabled and audit_dummy_context audit: do not panic on invalid boot parameter audit: track the owner of the command mutex ourselves audit: return on memory error to avoid null pointer dereference audit: bail before bug check if audit disabled audit: deprecate the AUDIT_FILTER_ENTRY filter audit: session ID should not set arch quick field pointer audit: update bugtracker and source URIs
2018-04-06make lookup_one_len() safe to use with directory locked sharedAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-04-06new helper: __lookup_slow()Al Viro
lookup_slow() sans locking/unlocking the directory Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-04-06merge common parts of lookup_one_len{,_unlocked} into common helperAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-04-06Merge 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 stuff, including Christoph's I_DIRTY patches" * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs: move I_DIRTY_INODE to fs.h ubifs: fix bogus __mark_inode_dirty(I_DIRTY_SYNC | I_DIRTY_DATASYNC) call ntfs: fix bogus __mark_inode_dirty(I_DIRTY_SYNC | I_DIRTY_DATASYNC) call gfs2: fix bogus __mark_inode_dirty(I_DIRTY_SYNC | I_DIRTY_DATASYNC) calls fs: fold open_check_o_direct into do_dentry_open vfs: Replace stray non-ASCII homoglyph characters with their ASCII equivalents vfs: make sure struct filename->iname is word-aligned get rid of pointless includes of fs_struct.h [poll] annotate SAA6588_CMD_POLL users
2018-04-04Merge branch 'work.dcache' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs dcache updates from Al Viro: "Part of this is what the trylock loop elimination series has turned into, part making d_move() preserve the parent (and thus the path) of victim, plus some general cleanups" * 'work.dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (22 commits) d_genocide: move export to definition fold dentry_lock_for_move() into its sole caller and clean it up make non-exchanging __d_move() copy ->d_parent rather than swap them oprofilefs: don't oops on allocation failure lustre: get rid of pointless casts to struct dentry * debugfs_lookup(): switch to lookup_one_len_unlocked() fold lookup_real() into __lookup_hash() take out orphan externs (empty_string/slash_string) split d_path() and friends into a separate file dcache.c: trim includes fs/dcache: Avoid a try_lock loop in shrink_dentry_list() get rid of trylock loop around dentry_kill() handle move to LRU in retain_dentry() dput(): consolidate the "do we need to retain it?" into an inlined helper split the slow part of lock_parent() off now lock_parent() can't run into killed dentry get rid of trylock loop in locking dentries on shrink list d_delete(): get rid of trylock loop fs/dcache: Move dentry_kill() below lock_parent() fs/dcache: Remove stale comment from dentry_kill() ...
2018-04-02Merge branch 'syscalls-next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/brodo/linux Pull removal of in-kernel calls to syscalls from Dominik Brodowski: "System calls are interaction points between userspace and the kernel. Therefore, system call functions such as sys_xyzzy() or compat_sys_xyzzy() should only be called from userspace via the syscall table, but not from elsewhere in the kernel. At least on 64-bit x86, it will likely be a hard requirement from v4.17 onwards to not call system call functions in the kernel: It is better to use use a different calling convention for system calls there, where struct pt_regs is decoded on-the-fly in a syscall wrapper which then hands processing over to the actual syscall function. This means that only those parameters which are actually needed for a specific syscall are passed on during syscall entry, instead of filling in six CPU registers with random user space content all the time (which may cause serious trouble down the call chain). Those x86-specific patches will be pushed through the x86 tree in the near future. Moreover, rules on how data may be accessed may differ between kernel data and user data. This is another reason why calling sys_xyzzy() is generally a bad idea, and -- at most -- acceptable in arch-specific code. This patchset removes all in-kernel calls to syscall functions in the kernel with the exception of arch/. On top of this, it cleans up the three places where many syscalls are referenced or prototyped, namely kernel/sys_ni.c, include/linux/syscalls.h and include/linux/compat.h" * 'syscalls-next' of git://git.kernel.org/pub/scm/linux/kernel/git/brodo/linux: (109 commits) bpf: whitelist all syscalls for error injection kernel/sys_ni: remove {sys_,sys_compat} from cond_syscall definitions kernel/sys_ni: sort cond_syscall() entries syscalls/x86: auto-create compat_sys_*() prototypes syscalls: sort syscall prototypes in include/linux/compat.h net: remove compat_sys_*() prototypes from net/compat.h syscalls: sort syscall prototypes in include/linux/syscalls.h kexec: move sys_kexec_load() prototype to syscalls.h x86/sigreturn: use SYSCALL_DEFINE0 x86: fix sys_sigreturn() return type to be long, not unsigned long x86/ioport: add ksys_ioperm() helper; remove in-kernel calls to sys_ioperm() mm: add ksys_readahead() helper; remove in-kernel calls to sys_readahead() mm: add ksys_mmap_pgoff() helper; remove in-kernel calls to sys_mmap_pgoff() mm: add ksys_fadvise64_64() helper; remove in-kernel call to sys_fadvise64_64() fs: add ksys_fallocate() wrapper; remove in-kernel calls to sys_fallocate() fs: add ksys_p{read,write}64() helpers; remove in-kernel calls to syscalls fs: add ksys_truncate() wrapper; remove in-kernel calls to sys_truncate() fs: add ksys_sync_file_range helper(); remove in-kernel calls to syscall kernel: add ksys_setsid() helper; remove in-kernel call to sys_setsid() kernel: add ksys_unshare() helper; remove in-kernel calls to sys_unshare() ...
2018-04-02fs: add do_linkat() helper and ksys_link() wrapper; remove in-kernel calls ↵Dominik Brodowski
to syscall Using the fs-internal do_linkat() helper allows us to get rid of fs-internal calls to the sys_linkat() syscall. Introducing the ksys_link() wrapper allows us to avoid the in-kernel calls to sys_link() syscall. The ksys_ prefix denotes that this function is meant as a drop-in replacement for the syscall. In particular, it uses the same calling convention as sys_link(). In the near future, the only fs-external user of ksys_link() should be converted to use vfs_link() instead. This patch is part of a series which removes in-kernel calls to syscalls. On this basis, the syscall entry path can be streamlined. For details, see http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02fs: add do_mknodat() helper and ksys_mknod() wrapper; remove in-kernel calls ↵Dominik Brodowski
to syscall Using the fs-internal do_mknodat() helper allows us to get rid of fs-internal calls to the sys_mknodat() syscall. Introducing the ksys_mknod() wrapper allows us to avoid the in-kernel calls to sys_mknod() syscall. The ksys_ prefix denotes that this function is meant as a drop-in replacement for the syscall. In particular, it uses the same calling convention as sys_mknod(). This patch is part of a series which removes in-kernel calls to syscalls. On this basis, the syscall entry path can be streamlined. For details, see http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02fs: add do_symlinkat() helper and ksys_symlink() wrapper; remove in-kernel ↵Dominik Brodowski
calls to syscall Using the fs-internal do_symlinkat() helper allows us to get rid of fs-internal calls to the sys_symlinkat() syscall. Introducing the ksys_symlink() wrapper allows us to avoid the in-kernel calls to the sys_symlink() syscall. The ksys_ prefix denotes that this function is meant as a drop-in replacement for the syscall. In particular, it uses the same calling convention as sys_symlink(). This patch is part of a series which removes in-kernel calls to syscalls. On this basis, the syscall entry path can be streamlined. For details, see http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02fs: add do_mkdirat() helper and ksys_mkdir() wrapper; remove in-kernel calls ↵Dominik Brodowski
to syscall Using the fs-internal do_mkdirat() helper allows us to get rid of fs-internal calls to the sys_mkdirat() syscall. Introducing the ksys_mkdir() wrapper allows us to avoid the in-kernel calls to the sys_mkdir() syscall. The ksys_ prefix denotes that this function is meant as a drop-in replacement for the syscall. In particular, it uses the same calling convention as sys_mkdir(). This patch is part of a series which removes in-kernel calls to syscalls. On this basis, the syscall entry path can be streamlined. For details, see http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02fs: add ksys_rmdir() wrapper; remove in-kernel calls to sys_rmdir()Dominik Brodowski
Using this wrapper allows us to avoid the in-kernel calls to the sys_rmdir() syscall. The ksys_ prefix denotes that this function is meant as a drop-in replacement for the syscall. In particular, it uses the same calling convention as sys_rmdir(). This patch is part of a series which removes in-kernel calls to syscalls. On this basis, the syscall entry path can be streamlined. For details, see http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02fs: add do_renameat2() helper; remove internal call to sys_renameat2()Dominik Brodowski
Using this helper removes in-kernel calls to the sys_renameat2() syscall. This patch is part of a series which removes in-kernel calls to syscalls. On this basis, the syscall entry path can be streamlined. For details, see http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-03-29fold lookup_real() into __lookup_hash()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-03-28fs: fold open_check_o_direct into do_dentry_openChristoph Hellwig
do_dentry_open is where we do the actual open of the file, so this is where we should do our O_DIRECT sanity check to cover all potential callers. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-03-21audit: add refused symlink to audit_namesRichard Guy Briggs
Audit link denied events for symlinks had duplicate PATH records rather than just updating the existing PATH record. Update the symlink's PATH record with the current dentry and inode information. See: https://github.com/linux-audit/audit-kernel/issues/21 Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-03-21audit: remove path param from link denied functionRichard Guy Briggs
In commit 45b578fe4c3cade6f4ca1fc934ce199afd857edc ("audit: link denied should not directly generate PATH record") the need for the struct path *link parameter was removed. Remove the now useless struct path argument. Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-03-19vfs: make sure struct filename->iname is word-alignedRasmus Villemoes
I noticed that offsetof(struct filename, iname) is actually 28 on 64 bit platforms, so we always pass an unaligned pointer to strncpy_from_user. This is mostly a problem for those 64 bit platforms without HAVE_EFFICIENT_UNALIGNED_ACCESS, but even on x86_64, unaligned accesses carry a penalty. A user-space microbenchmark doing nothing but strncpy_from_user from the same (aligned) source string runs about 5% faster when the destination is aligned. That number increases to 20% when the string is long enough (~32 bytes) that we cross a cache line boundary - that's for example the case for about half the files a "git status" in a kernel tree ends up stat'ing. This won't make any real-life workloads 5%, or even 1%, faster, but path lookup is common enough that cutting even a few cycles should be worthwhile. So ensure we always pass an aligned destination pointer to strncpy_from_user. Instead of explicit padding, simply swap the refcnt and aname members, as suggested by Al Viro. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-03-15fs: Teach path_connected to handle nfs filesystems with multiple roots.Eric W. Biederman
On nfsv2 and nfsv3 the nfs server can export subsets of the same filesystem and report the same filesystem identifier, so that the nfs client can know they are the same filesystem. The subsets can be from disjoint directory trees. The nfsv2 and nfsv3 filesystems provides no way to find the common root of all directory trees exported form the server with the same filesystem identifier. The practical result is that in struct super s_root for nfs s_root is not necessarily the root of the filesystem. The nfs mount code sets s_root to the root of the first subset of the nfs filesystem that the kernel mounts. This effects the dcache invalidation code in generic_shutdown_super currently called shrunk_dcache_for_umount and that code for years has gone through an additional list of dentries that might be dentry trees that need to be freed to accomodate nfs. When I wrote path_connected I did not realize nfs was so special, and it's hueristic for avoiding calling is_subdir can fail. The practical case where this fails is when there is a move of a directory from the subtree exposed by one nfs mount to the subtree exposed by another nfs mount. This move can happen either locally or remotely. With the remote case requiring that the move directory be cached before the move and that after the move someone walks the path to where the move directory now exists and in so doing causes the already cached directory to be moved in the dcache through the magic of d_splice_alias. If someone whose working directory is in the move directory or a subdirectory and now starts calling .. from the initial mount of nfs (where s_root == mnt_root), then path_connected as a heuristic will not bother with the is_subdir check. As s_root really is not the root of the nfs filesystem this heuristic is wrong, and the path may actually not be connected and path_connected can fail. The is_subdir function might be cheap enough that we can call it unconditionally. Verifying that will take some benchmarking and the result may not be the same on all kernels this fix needs to be backported to. So I am avoiding that for now. Filesystems with snapshots such as nilfs and btrfs do something similar. But as the directory tree of the snapshots are disjoint from one another and from the main directory tree rename won't move things between them and this problem will not occur. Cc: stable@vger.kernel.org Reported-by: Al Viro <viro@ZenIV.linux.org.uk> Fixes: 397d425dc26d ("vfs: Test for and handle paths that are unreachable from their mnt_root") Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-01-31Merge branch 'work.misc' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull misc vfs updates from Al Viro: "All kinds of misc stuff, without any unifying topic, from various people. Neil's d_anon patch, several bugfixes, introduction of kvmalloc analogue of kmemdup_user(), extending bitfield.h to deal with fixed-endians, assorted cleanups all over the place..." * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (28 commits) alpha: osf_sys.c: use timespec64 where appropriate alpha: osf_sys.c: fix put_tv32 regression jffs2: Fix use-after-free bug in jffs2_iget()'s error handling path dcache: delete unused d_hash_mask dcache: subtract d_hash_shift from 32 in advance fs/buffer.c: fold init_buffer() into init_page_buffers() fs: fold __inode_permission() into inode_permission() fs: add RWF_APPEND sctp: use vmemdup_user() rather than badly open-coding memdup_user() snd_ctl_elem_init_enum_names(): switch to vmemdup_user() replace_user_tlv(): switch to vmemdup_user() new primitive: vmemdup_user() memdup_user(): switch to GFP_USER eventfd: fold eventfd_ctx_get() into eventfd_ctx_fileget() eventfd: fold eventfd_ctx_read() into eventfd_read() eventfd: convert to use anon_inode_getfd() nfs4file: get rid of pointless include of btrfs.h uvc_v4l2: clean copyin/copyout up vme_user: don't use __copy_..._user() usx2y: don't bother with memdup_user() for 16-byte structure ...
2018-01-30Merge branch 'work.mqueue' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull mqueue/bpf vfs cleanups from Al Viro: "mqueue and bpf go through rather painful and similar contortions to create objects in their dentry trees. Provide a primitive for doing that without abusing ->mknod(), switch bpf and mqueue to it. Another mqueue-related thing that has ended up in that branch is on-demand creation of internal mount (based upon the work of Giuseppe Scrivano)" * 'work.mqueue' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: mqueue: switch to on-demand creation of internal mount tidy do_mq_open() up a bit mqueue: clean prepare_open() up do_mq_open(): move all work prior to dentry_open() into a helper mqueue: fold mq_attr_ok() into mqueue_get_inode() move dentry_open() calls up into do_mq_open() mqueue: switch to vfs_mkobj(), quit abusing ->d_fsdata bpf_obj_do_pin(): switch to vfs_mkobj(), quit abusing ->mknod() new primitive: vfs_mkobj()
2018-01-30Merge branch 'userns-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull userns updates from Eric Biederman: "Between the holidays and other distractions only a small amount of namespace work made it into my tree this time. Just a final cleanup from a revert several kernels ago and a small typo fix from Wolffhardt Schwabe" * 'userns-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: fix typo in assignment of fs default overflow gid autofs4: Modify autofs_wait to use current_uid() and current_gid() userns: Don't fail follow_automount based on s_user_ns
2018-01-25fs: fold __inode_permission() into inode_permission()Eric Biggers
Since commit 9c630ebefeee ("ovl: simplify permission checking"), overlayfs doesn't call __inode_permission() anymore, which leaves no users other than inode_permission(). So just fold it back into inode_permission(). Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-01-05new primitive: vfs_mkobj()Al Viro
Similar to vfs_create(), but with caller-supplied callback (and argument for it) to be used instead of ->create(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-11-30userns: Don't fail follow_automount based on s_user_nsEric W. Biederman
When vfs_submount was added the test to limit automounts from filesystems that with s_user_ns != &init_user_ns accidentially left in follow_automount. The test was never about any security concerns and was always about how do we implement this for filesystems whose s_user_ns != &init_user_ns. At the moment this check makes no difference as there are no filesystems that both set FS_USERNS_MOUNT and implement d_automount. Remove this check now while I am thinking about it so there will not be odd booby traps for someone who does want to make this combination work. vfs_submount still needs improvements to allow this combination to work, and vfs_submount contains a check that presents a warning. The autofs4 filesystem could be modified to set FS_USERNS_MOUNT and it would need not work on this code path, as userspace performs the mounts. Fixes: 93faccbbfa95 ("fs: Better permission checking for submounts") Fixes: aeaa4a79ff6a ("fs: Call d_automount with the filesystems creds") Acked-by: Ian Kent <raven@themaw.net> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2017-11-29autofs: revert "autofs: fix AT_NO_AUTOMOUNT not being honored"Ian Kent
Commit 42f461482178 ("autofs: fix AT_NO_AUTOMOUNT not being honored") allowed the fstatat(2) system call to properly honor the AT_NO_AUTOMOUNT flag but introduced a semantic change. In order to honor AT_NO_AUTOMOUNT a semantic change was made to the negative dentry case for stat family system calls in follow_automount(). This changed the unconditional triggering of an automount in this case to no longer be done and an error returned instead. This has caused more problems than I expected so reverting the change is needed. In a discussion with Neil Brown it was concluded that the automount(8) daemon can implement this change without kernel modifications. So that will be done instead and the autofs module documentation updated with a description of the problem and what needs to be done by module users for this specific case. Link: http://lkml.kernel.org/r/151174730120.6162.3848002191530283984.stgit@pluto.themaw.net Fixes: 42f4614821 ("autofs: fix AT_NO_AUTOMOUNT not being honored") Signed-off-by: Ian Kent <raven@themaw.net> Cc: Neil Brown <neilb@suse.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: David Howells <dhowells@redhat.com> Cc: Colin Walters <walters@redhat.com> Cc: Ondrej Holy <oholy@redhat.com> Cc: <stable@vger.kernel.org> [4.11+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17Merge 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 stuff, really no common topic here" * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: vfs: grab the lock instead of blocking in __fd_install during resizing vfs: stop clearing close on exec when closing a fd include/linux/fs.h: fix comment about struct address_space fs: make fiemap work from compat_ioctl coda: fix 'kernel memory exposure attempt' in fsync pstore: remove unneeded unlikely() vfs: remove unneeded unlikely() stubs for mount_bdev() and kill_block_super() in !CONFIG_BLOCK case make vfs_ustat() static do_handle_open() should be static elf_fdpic: fix unused variable warning fold destroy_super() into __put_super() new helper: destroy_unused_super() fix address space warnings in ipc/ acct.h: get rid of detritus
2017-11-17Merge branch 'misc.compat' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull compat and uaccess updates from Al Viro: - {get,put}_compat_sigset() series - assorted compat ioctl stuff - more set_fs() elimination - a few more timespec64 conversions - several removals of pointless access_ok() in places where it was followed only by non-__ variants of primitives * 'misc.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (24 commits) coredump: call do_unlinkat directly instead of sys_unlink fs: expose do_unlinkat for built-in callers ext4: take handling of EXT4_IOC_GROUP_ADD into a helper, get rid of set_fs() ipmi: get rid of pointless access_ok() pi433: sanitize ioctl cxlflash: get rid of pointless access_ok() mtdchar: get rid of pointless access_ok() r128: switch compat ioctls to drm_ioctl_kernel() selection: get rid of field-by-field copyin VT_RESIZEX: get rid of field-by-field copyin i2c compat ioctls: move to ->compat_ioctl() sched_rr_get_interval(): move compat to native, get rid of set_fs() mips: switch to {get,put}_compat_sigset() sparc: switch to {get,put}_compat_sigset() s390: switch to {get,put}_compat_sigset() ppc: switch to {get,put}_compat_sigset() parisc: switch to {get,put}_compat_sigset() get_compat_sigset() get rid of {get,put}_compat_itimerspec() io_getevents: Use timespec64 to represent timeouts ...