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2013-03-03fs: Limit sys_mount to only request filesystem modules.Eric W. Biederman
Modify the request_module to prefix the file system type with "fs-" and add aliases to all of the filesystems that can be built as modules to match. A common practice is to build all of the kernel code and leave code that is not commonly needed as modules, with the result that many users are exposed to any bug anywhere in the kernel. Looking for filesystems with a fs- prefix limits the pool of possible modules that can be loaded by mount to just filesystems trivially making things safer with no real cost. Using aliases means user space can control the policy of which filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf with blacklist and alias directives. Allowing simple, safe, well understood work-arounds to known problematic software. This also addresses a rare but unfortunate problem where the filesystem name is not the same as it's module name and module auto-loading would not work. While writing this patch I saw a handful of such cases. The most significant being autofs that lives in the module autofs4. This is relevant to user namespaces because we can reach the request module in get_fs_type() without having any special permissions, and people get uncomfortable when a user specified string (in this case the filesystem type) goes all of the way to request_module. After having looked at this issue I don't think there is any particular reason to perform any filtering or permission checks beyond making it clear in the module request that we want a filesystem module. The common pattern in the kernel is to call request_module() without regards to the users permissions. In general all a filesystem module does once loaded is call register_filesystem() and go to sleep. Which means there is not much attack surface exposed by loading a filesytem module unless the filesystem is mounted. In a user namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT, which most filesystems do not set today. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Acked-by: Kees Cook <keescook@chromium.org> Reported-by: Kees Cook <keescook@google.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2012-07-14VFS: Pass mount flags to sget()David Howells
Pass mount flags to sget() so that it can use them in initialising a new superblock before the set function is called. They could also be passed to the compare function. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-20logfs: missing cleanup on register_filesystem() failureAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-20switch open-coded instances of d_make_root() to new helperAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-20vfs: check i_nlink limits in vfs_{mkdir,rename_dir,link}Al Viro
New field of struct super_block - ->s_max_links. Maximal allowed value of ->i_nlink or 0; in the latter case all checks still need to be done in ->link/->mkdir/->rename instances. Note that this limit applies both to directoris and to non-directories. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-28logfs: Free areas before calling generic_shutdown_super()Joern Engel
Or hit an assertion in map_invalidatepage() instead. Signed-off-by: Joern Engel <joern@logfs.org>
2012-01-28logfs: set superblock shutdown flag after generic sb shutdownPrasad Joshi
While unmounting the file system LogFS calls generic_shutdown_super. The function does file system independent superblock shutdown. However, it might result in call file system specific inode eviction. LogFS marks FS shutting down by setting bit LOGFS_SB_FLAG_SHUTDOWN in super->s_flags. Since, inode eviction might call truncate on inode, following BUG is observed when file system is unmounted: ------------[ cut here ]------------ kernel BUG at /home/prasad/logfs/segment.c:362! invalid opcode: 0000 [#1] PREEMPT SMP CPU 3 Modules linked in: logfs binfmt_misc ppdev virtio_blk parport_pc lp parport psmouse floppy virtio_pci serio_raw virtio_ring virtio Pid: 1933, comm: umount Not tainted 3.0.0+ #4 Bochs Bochs RIP: 0010:[<ffffffffa008c841>] [<ffffffffa008c841>] logfs_segment_write+0x211/0x230 [logfs] RSP: 0018:ffff880062d7b9e8 EFLAGS: 00010202 RAX: 000000000000000e RBX: ffff88006eca9000 RCX: 0000000000000000 RDX: ffff88006fd87c40 RSI: ffffea00014ff468 RDI: ffff88007b68e000 RBP: ffff880062d7ba48 R08: 8000000020451430 R09: 0000000000000000 R10: dead000000100100 R11: 0000000000000000 R12: ffff88006fd87c40 R13: ffffea00014ff468 R14: ffff88005ad0a460 R15: 0000000000000000 FS: 00007f25d50ea760(0000) GS:ffff88007fd80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000d05e48 CR3: 0000000062c72000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process umount (pid: 1933, threadinfo ffff880062d7a000, task ffff880070b44500) Stack: ffff880062d7ba38 ffff88005ad0a508 0000000000001000 0000000000000000 8000000020451430 ffffea00014ff468 ffff880062d7ba48 ffff88005ad0a460 ffff880062d7bad8 ffffea00014ff468 ffff88006fd87c40 0000000000000000 Call Trace: [<ffffffffa0088fee>] logfs_write_i0+0x12e/0x190 [logfs] [<ffffffffa0089360>] __logfs_write_rec+0x140/0x220 [logfs] [<ffffffffa0089312>] __logfs_write_rec+0xf2/0x220 [logfs] [<ffffffffa00894a4>] logfs_write_rec+0x64/0xd0 [logfs] [<ffffffffa0089616>] __logfs_write_buf+0x106/0x110 [logfs] [<ffffffffa008a19e>] logfs_write_buf+0x4e/0x80 [logfs] [<ffffffffa008a6b8>] __logfs_write_inode+0x98/0x110 [logfs] [<ffffffffa008a7c4>] logfs_truncate+0x54/0x290 [logfs] [<ffffffffa008abfc>] logfs_evict_inode+0xdc/0x190 [logfs] [<ffffffff8115eef5>] evict+0x85/0x170 [<ffffffff8115f126>] iput+0xe6/0x1b0 [<ffffffff8115b4a8>] shrink_dcache_for_umount_subtree+0x218/0x280 [<ffffffff8115ce91>] shrink_dcache_for_umount+0x51/0x90 [<ffffffff8114796c>] generic_shutdown_super+0x2c/0x100 [<ffffffffa008cc47>] logfs_kill_sb+0x57/0xf0 [logfs] [<ffffffff81147de5>] deactivate_locked_super+0x45/0x70 [<ffffffff811487ea>] deactivate_super+0x4a/0x70 [<ffffffff81163934>] mntput_no_expire+0xa4/0xf0 [<ffffffff8116469f>] sys_umount+0x6f/0x380 [<ffffffff814dd46b>] system_call_fastpath+0x16/0x1b Code: 55 c8 49 8d b6 a8 00 00 00 45 89 f9 45 89 e8 4c 89 e1 4c 89 55 b8 c7 04 24 00 00 00 00 e8 68 fc ff ff 4c 8b 55 b8 e9 3c ff ff ff <0f> 0b 0f 0b c7 45 c0 00 00 00 00 e9 44 fe ff ff 66 66 66 66 66 RIP [<ffffffffa008c841>] logfs_segment_write+0x211/0x230 [logfs] RSP <ffff880062d7b9e8> ---[ end trace fe6b040cea952290 ]--- Therefore, move super->s_flags setting after the fs-indenpendent work has been finished. Reviewed-by: Joern Engel <joern@logfs.org> Signed-off-by: Prasad Joshi <prasadjoshi.linux@gmail.com>
2011-11-06Merge branch 'modsplit-Oct31_2011' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux * 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits) Revert "tracing: Include module.h in define_trace.h" irq: don't put module.h into irq.h for tracking irqgen modules. bluetooth: macroize two small inlines to avoid module.h ip_vs.h: fix implicit use of module_get/module_put from module.h nf_conntrack.h: fix up fallout from implicit moduleparam.h presence include: replace linux/module.h with "struct module" wherever possible include: convert various register fcns to macros to avoid include chaining crypto.h: remove unused crypto_tfm_alg_modname() inline uwb.h: fix implicit use of asm/page.h for PAGE_SIZE pm_runtime.h: explicitly requires notifier.h linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h miscdevice.h: fix up implicit use of lists and types stop_machine.h: fix implicit use of smp.h for smp_processor_id of: fix implicit use of errno.h in include/linux/of.h of_platform.h: delete needless include <linux/module.h> acpi: remove module.h include from platform/aclinux.h miscdevice.h: delete unnecessary inclusion of module.h device_cgroup.h: delete needless include <linux/module.h> net: sch_generic remove redundant use of <linux/module.h> net: inet_timewait_sock doesnt need <linux/module.h> ... Fix up trivial conflicts (other header files, and removal of the ab3550 mfd driver) in - drivers/media/dvb/frontends/dibx000_common.c - drivers/media/video/{mt9m111.c,ov6650.c} - drivers/mfd/ab3550-core.c - include/linux/dmaengine.h
2011-10-31lib/string.c: introduce memchr_inv()Akinobu Mita
memchr_inv() is mainly used to check whether the whole buffer is filled with just a specified byte. The function name and prototype are stolen from logfs and the implementation is from SLUB. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Acked-by: Christoph Lameter <cl@linux-foundation.org> Acked-by: Pekka Enberg <penberg@kernel.org> Cc: Matt Mackall <mpm@selenic.com> Acked-by: Joern Engel <joern@logfs.org> Cc: Marcin Slusarz <marcin.slusarz@gmail.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31fs: add module.h to files that were implicitly using itPaul Gortmaker
Some files were using the complete module.h infrastructure without actually including the header at all. Fix them up in advance so once the implicit presence is removed, we won't get failures like this: CC [M] fs/nfsd/nfssvc.o fs/nfsd/nfssvc.c: In function 'nfsd_create_serv': fs/nfsd/nfssvc.c:335: error: 'THIS_MODULE' undeclared (first use in this function) fs/nfsd/nfssvc.c:335: error: (Each undeclared identifier is reported only once fs/nfsd/nfssvc.c:335: error: for each function it appears in.) fs/nfsd/nfssvc.c: In function 'nfsd': fs/nfsd/nfssvc.c:555: error: implicit declaration of function 'module_put_and_exit' make[3]: *** [fs/nfsd/nfssvc.o] Error 1 Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-05-03logfs: initialize superblock entries earlierLinus Torvalds
In particular, s_freeing_list needs to be initialized early, since it is used on some of the error paths when mounts fail. The mapping inode, for example, would be initialized and then free'd on an error path before s_freeing_list was initialized, but the inode drop operation needs the s_freeing_list to be set up. Normally you'd never see this, because not only is logfs fairly rare, but a successful mount will never have any issues. Reported-by: werner <w.landgraf@ru.ru> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-29switch logfs to ->mount()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-29logfs: fix a leak in get_sbAl Viro
a) switch ->put_device() to logfs_super * b) actually call it on early failures in logfs_get_sb_device() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-29logfs get_sb, part 3Al Viro
take logfs_get_sb_device() calls to logfs_get_sb() itself Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-29logfs get_sb, part 2Al Viro
take setting s_bdev/s_mtd/s_devops to callers of logfs_get_sb_device(), don't bother passing them separately Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-29logfs get_sb massage, part 1Al Viro
move allocation of logfs_super to logfs_get_sb, pass it to logfs_get_sb_...(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-09logfs: get rid of magical inodesAl Viro
ordering problems at ->kill_sb() time are solved by doing iput() of these suckers in ->put_super() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-05-17Merge git://git.kernel.org/pub/scm/linux/kernel/git/joern/logfsLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/joern/logfs: logfs: handle powerfail on NAND flash logfs: handle errors from get_mtd_device() logfs: remove unused variable logfs: fix sync logfs: fix compile failure logfs: initialize li->li_refcount logfs: commit reservations under space pressure logfs: survive logfs_buf_recover read errors logfs: Close i_ino reuse race logfs: fix logfs_seek_hole() logfs: Return -EINVAL if filesystem image doesn't match LogFS: Fix typo in b6349ac8 logfs: testing the wrong variable
2010-05-15Fix double-free in logfsAl Viro
iput() is needed *until* we'd done successful d_alloc_root() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-05-05logfs: fix compile failureJoern Engel
When CONFIG_BLOCK is not enabled: fs/logfs/super.c:142: error: implicit declaration of function 'bdev_get_queue' fs/logfs/super.c:142: error: invalid type argument of '->' (have 'int') Found by Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Joern Engel <joern@logfs.org>
2010-05-01logfs: Return -EINVAL if filesystem image doesn't matchJoern Engel
Signed-off-by: Joern Engel <joern@logfs.org>
2010-04-29logfs: testing the wrong variableDan Carpenter
There is a typo here. We should test "last" instead of "first". Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Joern Engel <joern@logfs.org>
2010-04-21Merge git://git.kernel.org/pub/scm/linux/kernel/git/joern/logfsLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/joern/logfs: [LogFS] Split large truncated into smaller chunks [LogFS] Set s_bdi [LogFS] Prevent mempool_destroy NULL pointer dereference [LogFS] Move assertion [LogFS] Plug 8 byte information leak [LogFS] Prevent memory corruption on large deletes [LogFS] Remove unused method Fix trivial conflict with added header includes in fs/logfs/super.c
2010-04-17[LogFS] Set s_bdiJoern Engel
Since 32a88aa1 sync() was turned into a NOP for logfs. Worse, sync() would not return an error, giving the illusion that writeout had actually happened. Afaics jffs2 was broken as well. Signed-off-by: Joern Engel <joern@logfs.org>
2010-04-15[LogFS] Prevent mempool_destroy NULL pointer dereferenceJoern Engel
It would probably be better to just accept NULL pointers in mempool_destroy(). But for the current -rc series let's keep things simple. This patch was lost in the cracks for a while. Kevin Cernekee <cernekee@gmail.com> had to rediscover the problem and send a similar patch because of it. :( Signed-off-by: Joern Engel <joern@logfs.org>
2010-04-13[LogFS] Prevent memory corruption on large deletesJoern Engel
Removing sufficiently large files would create aliases for a large number of segments. This in turn results in a large number of journal entries and an overflow of s_je_array. Cheap fix is to add a BUG_ON, turning memory corruption into something annoying, but less dangerous. Real fix is to count the number of affected segments and prevent the problem completely. Signed-off-by: Joern Engel <joern@logfs.org>
2010-04-05Merge branch 'master' into export-slabhTejun Heo
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-27Use deactivate_locked_superJoern Engel
Found by Al Viro. Signed-off-by: Joern Engel <joern@logfs.org>
2010-03-27Fix logfs_get_sb_final error pathJoern Engel
rootdir was already allocated, so we must iput it again. Found by Al Viro. Signed-off-by: Joern Engel <joern@logfs.org>
2010-03-27Write out both superblocks on mismatchJoern Engel
If the first superblock is wrong and the second gets written, there will still be a mismatch on next mount. Write both to make sure they match. Signed-off-by: Joern Engel <joern@logfs.org>
2010-03-27Open segment file before using itJoern Engel
logfs_recover_sb() needs it open. Signed-off-by: Joern Engel <joern@logfs.org>
2010-03-05[LogFS] Check feature flagsJoern Engel
2010-03-04[LogFS] Only write journal if dirtyJoern Engel
This prevents unnecessary journal writes. More importantly it prevents an oops due to a journal write on failed mount.
2010-03-04[LogFS] Fix bdev erasesJoern Engel
Erases for block devices were always just emulated by writing 0xff. Some time back the write was removed and only the page cache was changed to 0xff. Superficialy a good idea with two problems: 1. Touching the page cache isn't necessary either. 2. However, writing out 0xff _is_ necessary for the journal. As the journal is scanned linearly, an old non-overwritten commit entry can be used on next mount and cause havoc. This should fix both aspects.
2009-11-20[LogFS] add new flash file systemJoern Engel
This is a new flash file system. See Documentation/filesystems/logfs.txt Signed-off-by: Joern Engel <joern@logfs.org>