user/sven/linux.git/fs/hfsplus, branch stable/4.3.y

hfs,hfsplus: cache pages correctly between bnode_create and bnode_free

2015-09-10T20:29:01Z

Pages looked up by __hfs_bnode_create() (called by hfs_bnode_create() and hfs_bnode_find() for finding or creating pages corresponding to an inode) are immediately kmap()'ed and used (both read and write) and kunmap()'ed, and should not be page_cache_release()'ed until hfs_bnode_free(). This patch fixes a problem I first saw in July 2012: merely running "du" on a large hfsplus-mounted directory a few times on a reasonably loaded system would get the hfsplus driver all confused and complaining about B-tree inconsistencies, and generates a "BUG: Bad page state". Most recently, I can generate this problem on up-to-date Fedora 22 with shipped kernel 4.0.5, by running "du /" (="/" + "/home" + "/mnt" + other smaller mounts) and "du /mnt" simultaneously on two windows, where /mnt is a lightly-used QEMU VM image of the full Mac OS X 10.9: $ df -i / /home /mnt Filesystem Inodes IUsed IFree IUse% Mounted on /dev/mapper/fedora-root 3276800 551665 2725135 17% / /dev/mapper/fedora-home 52879360 716221 52163139 2% /home /dev/nbd0p2 4294967295 1387818 4293579477 1% /mnt After applying the patch, I was able to run "du /" (60+ times) and "du /mnt" (150+ times) continuously and simultaneously for 6+ hours. There are many reports of the hfsplus driver getting confused under load and generating "BUG: Bad page state" or other similar issues over the years. [1] The unpatched code [2] has always been wrong since it entered the kernel tree. The only reason why it gets away with it is that the kmap/memcpy/kunmap follow very quickly after the page_cache_release() so the kernel has not had a chance to reuse the memory for something else, most of the time. The current RW driver appears to have followed the design and development of the earlier read-only hfsplus driver [3], where-by version 0.1 (Dec 2001) had a B-tree node-centric approach to read_cache_page()/page_cache_release() per bnode_get()/bnode_put(), migrating towards version 0.2 (June 2002) of caching and releasing pages per inode extents. When the current RW code first entered the kernel [2] in 2005, there was an REF_PAGES conditional (and "//" commented out code) to switch between B-node centric paging to inode-centric paging. There was a mistake with the direction of one of the REF_PAGES conditionals in __hfs_bnode_create(). In a subsequent "remove debug code" commit [4], the read_cache_page()/page_cache_release() per bnode_get()/bnode_put() were removed, but a page_cache_release() was mistakenly left in (propagating the "REF_PAGES <-> !REF_PAGE" mistake), and the commented-out page_cache_release() in bnode_release() (which should be spanned by !REF_PAGES) was never enabled. References: [1]: Michael Fox, Apr 2013 http://www.spinics.net/lists/linux-fsdevel/msg63807.html ("hfsplus volume suddenly inaccessable after 'hfs: recoff %d too large'") Sasha Levin, Feb 2015 http://lkml.org/lkml/2015/2/20/85 ("use after free") https://bugs.launchpad.net/ubuntu/+source/linux/+bug/740814 https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1027887 https://bugzilla.kernel.org/show_bug.cgi?id=42342 https://bugzilla.kernel.org/show_bug.cgi?id=63841 https://bugzilla.kernel.org/show_bug.cgi?id=78761 [2]: http://git.kernel.org/cgit/linux/kernel/git/tglx/history.git/commit/\ fs/hfs/bnode.c?id=d1081202f1d0ee35ab0beb490da4b65d4bc763db commit d1081202f1d0ee35ab0beb490da4b65d4bc763db Author: Andrew Morton Date: Wed Feb 25 16:17:36 2004 -0800 [PATCH] HFS rewrite http://git.kernel.org/cgit/linux/kernel/git/tglx/history.git/commit/\ fs/hfsplus/bnode.c?id=91556682e0bf004d98a529bf829d339abb98bbbd commit 91556682e0bf004d98a529bf829d339abb98bbbd Author: Andrew Morton Date: Wed Feb 25 16:17:48 2004 -0800 [PATCH] HFS+ support [3]: http://sourceforge.net/projects/linux-hfsplus/ http://sourceforge.net/projects/linux-hfsplus/files/Linux%202.4.x%20patch/hfsplus%200.1/ http://sourceforge.net/projects/linux-hfsplus/files/Linux%202.4.x%20patch/hfsplus%200.2/ http://linux-hfsplus.cvs.sourceforge.net/viewvc/linux-hfsplus/linux/\ fs/hfsplus/bnode.c?r1=1.4&r2=1.5 Date: Thu Jun 6 09:45:14 2002 +0000 Use buffer cache instead of page cache in bnode.c. Cache inode extents. [4]: http://git.kernel.org/cgit/linux/kernel/git/\ stable/linux-stable.git/commit/?id=a5e3985fa014029eb6795664c704953720cc7f7d commit a5e3985fa014029eb6795664c704953720cc7f7d Author: Roman Zippel Date: Tue Sep 6 15:18:47 2005 -0700 [PATCH] hfs: remove debug code Signed-off-by: Hin-Tak Leung Signed-off-by: Sergei Antonov Reviewed-by: Anton Altaparmakov Reported-by: Sasha Levin Cc: Al Viro Cc: Christoph Hellwig Cc: Vyacheslav Dubeyko Cc: Sougata Santra Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

fs: create and use seq_show_option for escaping

2015-09-04T23:54:41Z

Many file systems that implement the show_options hook fail to correctly escape their output which could lead to unescaped characters (e.g. new lines) leaking into /proc/mounts and /proc/[pid]/mountinfo files. This could lead to confusion, spoofed entries (resulting in things like systemd issuing false d-bus "mount" notifications), and who knows what else. This looks like it would only be the root user stepping on themselves, but it's possible weird things could happen in containers or in other situations with delegated mount privileges. Here's an example using overlay with setuid fusermount trusting the contents of /proc/mounts (via the /etc/mtab symlink). Imagine the use of "sudo" is something more sneaky: $ BASE="ovl" $ MNT="$BASE/mnt" $ LOW="$BASE/lower" $ UP="$BASE/upper" $ WORK="$BASE/work/ 0 0 none /proc fuse.pwn user_id=1000" $ mkdir -p "$LOW" "$UP" "$WORK" $ sudo mount -t overlay -o "lowerdir=$LOW,upperdir=$UP,workdir=$WORK" none /mnt $ cat /proc/mounts none /root/ovl/mnt overlay rw,relatime,lowerdir=ovl/lower,upperdir=ovl/upper,workdir=ovl/work/ 0 0 none /proc fuse.pwn user_id=1000 0 0 $ fusermount -u /proc $ cat /proc/mounts cat: /proc/mounts: No such file or directory This fixes the problem by adding new seq_show_option and seq_show_option_n helpers, and updating the vulnerable show_option handlers to use them as needed. Some, like SELinux, need to be open coded due to unusual existing escape mechanisms. [akpm@linux-foundation.org: add lost chunk, per Kees] [keescook@chromium.org: seq_show_option should be using const parameters] Signed-off-by: Kees Cook Acked-by: Serge Hallyn Acked-by: Jan Kara Acked-by: Paul Moore Cc: J. R. Okajima Signed-off-by: Kees Cook Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

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

2015-07-05T02:36:06Z

Pull more vfs updates from Al Viro: "Assorted VFS fixes and related cleanups (IMO the most interesting in that part are f_path-related things and Eric's descriptor-related stuff). UFS regression fixes (it got broken last cycle). 9P fixes. fs-cache series, DAX patches, Jan's file_remove_suid() work" [ I'd say this is much more than "fixes and related cleanups". The file_table locking rule change by Eric Dumazet is a rather big and fundamental update even if the patch isn't huge. - Linus ] * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (49 commits) 9p: cope with bogus responses from server in p9_client_{read,write} p9_client_write(): avoid double p9_free_req() 9p: forgetting to cancel request on interrupted zero-copy RPC dax: bdev_direct_access() may sleep block: Add support for DAX reads/writes to block devices dax: Use copy_from_iter_nocache dax: Add block size note to documentation fs/file.c: __fget() and dup2() atomicity rules fs/file.c: don't acquire files->file_lock in fd_install() fs:super:get_anon_bdev: fix race condition could cause dev exceed its upper limitation vfs: avoid creation of inode number 0 in get_next_ino namei: make set_root_rcu() return void make simple_positive() public ufs: use dir_pages instead of ufs_dir_pages() pagemap.h: move dir_pages() over there remove the pointless include of lglock.h fs: cleanup slight list_entry abuse xfs: Correctly lock inode when removing suid and file capabilities fs: Call security_ops->inode_killpriv on truncate fs: Provide function telling whether file_remove_privs() will do anything ...

fs: cleanup slight list_entry abuse

2015-06-23T22:01:59Z

list_entry is just a wrapper for container_of, but it is arguably wrong (and slightly confusing) to use it when the pointed-to struct member is not a struct list_head. Use container_of directly instead. Signed-off-by: Rasmus Villemoes Signed-off-by: Al Viro

writeback: separate out include/linux/backing-dev-defs.h

2015-06-02T14:33:34Z

With the planned cgroup writeback support, backing-dev related declarations will be more widely used across block and cgroup; unfortunately, including backing-dev.h from include/linux/blkdev.h makes cyclic include dependency quite likely. This patch separates out backing-dev-defs.h which only has the essential definitions and updates blkdev.h to include it. c files which need access to more backing-dev details now include backing-dev.h directly. This takes backing-dev.h off the common include dependency chain making it a lot easier to use it across block and cgroup. v2: fs/fat build failure fixed. Signed-off-by: Tejun Heo Reviewed-by: Jan Kara Cc: Jens Axboe Signed-off-by: Jens Axboe

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

2015-04-27T00:22:07Z

Pull fourth vfs update from Al Viro: "d_inode() annotations from David Howells (sat in for-next since before the beginning of merge window) + four assorted fixes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: RCU pathwalk breakage when running into a symlink overmounting something fix I_DIO_WAKEUP definition direct-io: only inc/dec inode->i_dio_count for file systems fs/9p: fix readdir() VFS: assorted d_backing_inode() annotations VFS: fs/inode.c helpers: d_inode() annotations VFS: fs/cachefiles: d_backing_inode() annotations VFS: fs library helpers: d_inode() annotations VFS: assorted weird filesystems: d_inode() annotations VFS: normal filesystems (and lustre): d_inode() annotations VFS: security/: d_inode() annotations VFS: security/: d_backing_inode() annotations VFS: net/: d_inode() annotations VFS: net/unix: d_backing_inode() annotations VFS: kernel/: d_inode() annotations VFS: audit: d_backing_inode() annotations VFS: Fix up some ->d_inode accesses in the chelsio driver VFS: Cachefiles should perform fs modifications on the top layer only VFS: AF_UNIX sockets should call mknod on the top layer only

Merge branch 'akpm' (patches from Andrew)

2015-04-17T13:04:38Z

Merge third patchbomb from Andrew Morton: - various misc things - a couple of lib/ optimisations - provide DIV_ROUND_CLOSEST_ULL() - checkpatch updates - rtc tree - befs, nilfs2, hfs, hfsplus, fatfs, adfs, affs, bfs - ptrace fixes - fork() fixes - seccomp cleanups - more mmap_sem hold time reductions from Davidlohr * emailed patches from Andrew Morton : (138 commits) proc: show locks in /proc/pid/fdinfo/X docs: add missing and new /proc/PID/status file entries, fix typos drivers/rtc/rtc-at91rm9200.c: make IO endian agnostic Documentation/spi/spidev_test.c: fix warning drivers/rtc/rtc-s5m.c: allow usage on device type different than main MFD type .gitignore: ignore *.tar MAINTAINERS: add Mediatek SoC mailing list tomoyo: reduce mmap_sem hold for mm->exe_file powerpc/oprofile: reduce mmap_sem hold for exe_file oprofile: reduce mmap_sem hold for mm->exe_file mips: ip32: add platform data hooks to use DS1685 driver lib/Kconfig: fix up HAVE_ARCH_BITREVERSE help text x86: switch to using asm-generic for seccomp.h sparc: switch to using asm-generic for seccomp.h powerpc: switch to using asm-generic for seccomp.h parisc: switch to using asm-generic for seccomp.h mips: switch to using asm-generic for seccomp.h microblaze: use asm-generic for seccomp.h arm: use asm-generic for seccomp.h seccomp: allow COMPAT sigreturn overrides ...

hfsplus: don't store special "osx" xattr prefix on-disk

2015-04-17T13:04:05Z

On Mac OS X, HFS+ extended attributes are not namespaced. Since we want to be compatible with OS X filesystems and yet still support the Linux namespacing system, the hfsplus driver implements a special "osx" namespace that is reported for any attribute that is not namespaced on-disk. However, the current code for getting and setting these unprefixed attributes is broken. hfsplus_osx_setattr() and hfsplus_osx_getattr() are passed names that have already had their "osx." prefixes stripped by the generic functions. The functions first, quite correctly, check those names to make sure that they aren't prefixed with a known namespace, which would allow namespace access restrictions to be bypassed. However, the functions then prepend "osx." to the name they're given before passing it on to hfsplus_getattr() and hfsplus_setattr(). Not only does this cause the "osx." prefix to be stored on-disk, defeating its purpose, it also breaks the check for the special "com.apple.FinderInfo" attribute, which is reported for all files, and as a consequence makes some userspace applications (e.g. GNU patch) fail even when extended attributes are not otherwise in use. There are five commits which have touched this particular code: 127e5f5ae51e ("hfsplus: rework functionality of getting, setting and deleting of extended attributes") b168fff72109 ("hfsplus: use xattr handlers for removexattr") bf29e886b242 ("hfsplus: correct usage of HFSPLUS_ATTR_MAX_STRLEN for non-English attributes") fcacbd95e121 ("fs/hfsplus: move xattr_name allocation in hfsplus_getxattr()") ec1bbd346f18 ("fs/hfsplus: move xattr_name allocation in hfsplus_setxattr()") The first commit creates the functions to begin with. The namespace is prepended by the original code, which I believe was correct at the time, since hfsplus_?etattr() stripped the prefix if found. The second commit removes this behavior from hfsplus_?etattr() and appears to have been intended to also remove the prefixing from hfsplus_osx_?etattr(). However, what it actually does is remove a necessary strncpy() call completely, breaking the osx namespace entirely. The third commit re-adds the strncpy() call as it was originally, but doesn't mention it in its commit message. The final two commits refactor the code and don't affect its functionality. This commit does what b168fff attempted to do (prevent the prefix from being added), but does it properly, instead of passing in an empty buffer (which is what b168fff actually did). Fixes: b168fff72109 ("hfsplus: use xattr handlers for removexattr") Signed-off-by: Thomas Hebb Cc: Hin-Tak Leung Cc: Sergei Antonov Cc: Anton Altaparmakov Cc: Fabian Frederick Cc: Christian Kujau Cc: Christoph Hellwig Cc: Al Viro Cc: Viacheslav Dubeyko Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

hfsplus: fix expand when not enough available space

2015-04-17T13:04:05Z

Fix a bug which is reproduced as follows. Create a file: echo abc > test_file Try to expand the file beyond available space: truncate --size= test_file Since HFS+ does not support file size > allocated size, truncate should fail. However, it ends successfully. The driver returns success despite having been unable to allocate the requested space for the file. Also filesystem check finds an error: Checking catalog file. Incorrect size for file test_file (It should be 469094400 instead of 1000000000) Add a piece of code analogous to code in the fat driver. Now a proper error is returned and filesystem remains consistent. Signed-off-by: Sergei Antonov Cc: Vyacheslav Dubeyko Cc: Hin-Tak Leung Reviewed-by: Anton Altaparmakov Cc: Al Viro Cc: Christoph Hellwig Cc: Sougata Santra Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

hfsplus: incorrect return value

2015-04-17T13:04:05Z

In case of memory allocation error, the return should be -ENOMEM, instead of -ENOSPC. Signed-off-by: Chengyu Song Reviewed-by: Sergei Antonov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds