linux/fs, branch v3.0.85

UBIFS: fix a horrid bug

2013-07-03T18:03:24Z

commit 605c912bb843c024b1ed173dc427cd5c08e5d54d upstream. Al Viro pointed me to the fact that '->readdir()' and '->llseek()' have no mutual exclusion, which means the 'ubifs_dir_llseek()' can be run while we are in the middle of 'ubifs_readdir()'. This means that 'file->private_data' can be freed while 'ubifs_readdir()' uses it, and this is a very bad bug: not only 'ubifs_readdir()' can return garbage, but this may corrupt memory and lead to all kinds of problems like crashes an security holes. This patch fixes the problem by using the 'file->f_version' field, which '->llseek()' always unconditionally sets to zero. We set it to 1 in 'ubifs_readdir()' and whenever we detect that it became 0, we know there was a seek and it is time to clear the state saved in 'file->private_data'. I tested this patch by writing a user-space program which runds readdir and seek in parallell. I could easily crash the kernel without these patches, but could not crash it with these patches. Reported-by: Al Viro Tested-by: Artem Bityutskiy Signed-off-by: Artem Bityutskiy Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman

UBIFS: prepare to fix a horrid bug

2013-07-03T18:03:24Z

commit 33f1a63ae84dfd9ad298cf275b8f1887043ced36 upstream. Al Viro pointed me to the fact that '->readdir()' and '->llseek()' have no mutual exclusion, which means the 'ubifs_dir_llseek()' can be run while we are in the middle of 'ubifs_readdir()'. First of all, this means that 'file->private_data' can be freed while 'ubifs_readdir()' uses it. But this particular patch does not fix the problem. This patch is only a preparation, and the fix will follow next. In this patch we make 'ubifs_readdir()' stop using 'file->f_pos' directly, because 'file->f_pos' can be changed by '->llseek()' at any point. This may lead 'ubifs_readdir()' to returning inconsistent data: directory entry names may correspond to incorrect file positions. So here we introduce a local variable 'pos', read 'file->f_pose' once at very the beginning, and then stick to 'pos'. The result of this is that when 'ubifs_dir_llseek()' changes 'file->f_pos' while we are in the middle of 'ubifs_readdir()', the latter "wins". Reported-by: Al Viro Tested-by: Artem Bityutskiy Signed-off-by: Artem Bityutskiy Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman

perf: Disable monitoring on setuid processes for regular users

2013-07-03T18:03:23Z

commit 2976b10f05bd7f6dab9f9e7524451ddfed656a89 upstream. There was a a bug in setup_new_exec(), whereby the test to disabled perf monitoring was not correct because the new credentials for the process were not yet committed and therefore the get_dumpable() test was never firing. The patch fixes the problem by moving the perf_event test until after the credentials are committed. Signed-off-by: Stephane Eranian Tested-by: Jiri Olsa Acked-by: Peter Zijlstra Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

ceph: fix statvfs fr_size

2013-06-20T18:28:21Z

commit 92a49fb0f79f3300e6e50ddf56238e70678e4202 upstream. Different versions of glibc are broken in different ways, but the short of it is that for the time being, frsize should == bsize, and be used as the multiple for the blocks, free, and available fields. This mirrors what is done for NFS. The previous reporting of the page size for frsize meant that newer glibc and df would report a very small value for the fs size. Fixes http://tracker.ceph.com/issues/3793. Signed-off-by: Sage Weil Reviewed-by: Greg Farnum Signed-off-by: Greg Kroah-Hartman

jfs: fix a couple races

2013-06-07T19:46:48Z

commit 73aaa22d5ffb2630456bac2f9a4ed9b81d0d7271 upstream. This patch fixes races uncovered by xfstests testcase 068. One race is the result of jfs_sync() trying to write a sync point to the journal after it has been frozen (or possibly in the process). Since freezing sync's the journal, there is no need to write a sync point so we simply want to return. The second involves jfs_write_inode() being called on a deleted inode. It calls jfs_flush_journal which is held up by the jfs_commit thread doing the final iput on the same deleted inode, which itself is waiting for the I_SYNC flag to be cleared. jfs_write_inode need not do anything when i_nlink is zero, which is the easy fix. Reported-by: Michael L. Semon Signed-off-by: Dave Kleikamp Signed-off-by: Greg Kroah-Hartman

cifs: fix potential buffer overrun when composing a new options string

2013-06-07T19:46:48Z

commit 166faf21bd14bc5c5295a44874bf7f3930c30b20 upstream. Consider the case where we have a very short ip= string in the original mount options, and when we chase a referral we end up with a very long IPv6 address. Be sure to allow for that possibility when estimating the size of the string to allocate. Signed-off-by: Jeff Layton Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman

nilfs2: fix issue of nilfs_set_page_dirty() for page at EOF boundary

2013-06-07T19:46:36Z

commit 136e8770cd5d1fe38b3c613100dd6dc4db6d4fa6 upstream. nilfs2: fix issue of nilfs_set_page_dirty for page at EOF boundary DESCRIPTION: There are use-cases when NILFS2 file system (formatted with block size lesser than 4 KB) can be remounted in RO mode because of encountering of "broken bmap" issue. The issue was reported by Anthony Doggett : "The machine I've been trialling nilfs on is running Debian Testing, Linux version 3.2.0-4-686-pae (debian-kernel@lists.debian.org) (gcc version 4.6.3 (Debian 4.6.3-14) ) #1 SMP Debian 3.2.35-2), but I've also reproduced it (identically) with Debian Unstable amd64 and Debian Experimental (using the 3.8-trunk kernel). The problematic partitions were formatted with "mkfs.nilfs2 -b 1024 -B 8192"." SYMPTOMS: (1) System log contains error messages likewise: [63102.496756] nilfs_direct_assign: invalid pointer: 0 [63102.496786] NILFS error (device dm-17): nilfs_bmap_assign: broken bmap (inode number=28) [63102.496798] [63102.524403] Remounting filesystem read-only (2) The NILFS2 file system is remounted in RO mode. REPRODUSING PATH: (1) Create volume group with name "unencrypted" by means of vgcreate utility. (2) Run script (prepared by Anthony Doggett ): ----------------[BEGIN SCRIPT]-------------------- VG=unencrypted lvcreate --size 2G --name ntest $VG mkfs.nilfs2 -b 1024 -B 8192 /dev/mapper/$VG-ntest mkdir /var/tmp/n mkdir /var/tmp/n/ntest mount /dev/mapper/$VG-ntest /var/tmp/n/ntest mkdir /var/tmp/n/ntest/thedir cd /var/tmp/n/ntest/thedir sleep 2 date darcs init sleep 2 dmesg|tail -n 5 date darcs whatsnew || true date sleep 2 dmesg|tail -n 5 ----------------[END SCRIPT]-------------------- REPRODUCIBILITY: 100% INVESTIGATION: As it was discovered, the issue takes place during segment construction after executing such sequence of user-space operations: open("_darcs/index", O_RDWR|O_CREAT|O_NOCTTY, 0666) = 7 fstat(7, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0 ftruncate(7, 60) The error message "NILFS error (device dm-17): nilfs_bmap_assign: broken bmap (inode number=28)" takes place because of trying to get block number for third block of the file with logical offset #3072 bytes. As it is possible to see from above output, the file has 60 bytes of the whole size. So, it is enough one block (1 KB in size) allocation for the whole file. Trying to operate with several blocks instead of one takes place because of discovering several dirty buffers for this file in nilfs_segctor_scan_file() method. The root cause of this issue is in nilfs_set_page_dirty function which is called just before writing to an mmapped page. When nilfs_page_mkwrite function handles a page at EOF boundary, it fills hole blocks only inside EOF through __block_page_mkwrite(). The __block_page_mkwrite() function calls set_page_dirty() after filling hole blocks, thus nilfs_set_page_dirty function (= a_ops->set_page_dirty) is called. However, the current implementation of nilfs_set_page_dirty() wrongly marks all buffers dirty even for page at EOF boundary. As a result, buffers outside EOF are inconsistently marked dirty and queued for write even though they are not mapped with nilfs_get_block function. FIX: This modifies nilfs_set_page_dirty() not to mark hole blocks dirty. Thanks to Vyacheslav Dubeyko for his effort on analysis and proposals for this issue. Signed-off-by: Ryusuke Konishi Reported-by: Anthony Doggett Reported-by: Vyacheslav Dubeyko Cc: Vyacheslav Dubeyko Tested-by: Ryusuke Konishi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

ocfs2: goto out_unlock if ocfs2_get_clusters_nocache() failed in ocfs2_fiemap()

2013-06-07T19:46:36Z

commit b4ca2b4b577c3530e34dcfaafccb2cc680ce95d1 upstream. Last time we found there is lock/unlock bug in ocfs2_file_aio_write, and then we did a thorough search for all lock resources in ocfs2_inode_info, including rw, inode and open lockres and found this bug. My kernel version is 3.0.13, and it is also in the lastest version 3.9. In ocfs2_fiemap, once ocfs2_get_clusters_nocache failed, it should goto out_unlock instead of out, because we need release buffer head, up read alloc sem and unlock inode. Signed-off-by: Joseph Qi Reviewed-by: Jie Liu Cc: Mark Fasheh Cc: Joel Becker Acked-by: Sunil Mushran Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

fat: fix possible overflow for fat_clusters

2013-06-07T19:46:35Z

commit 7b92d03c3239f43e5b86c9cc9630f026d36ee995 upstream. Intermediate value of fat_clusters can be overflowed on 32bits arch. Reported-by: Krzysztof Strasburger Signed-off-by: OGAWA Hirofumi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

cifs: only set ops for inodes in I_NEW state

2013-06-07T19:46:35Z

commit c2b93e0699723700f886ce17bb65ffd771195a6d upstream. It's generally not safe to reset the inode ops once they've been set. In the case where the inode was originally thought to be a directory and then later found to be a DFS referral, this can lead to an oops when we try to trigger an inode op on it after changing the ops to the blank referral operations. Reported-and-Tested-by: Sachin Prabhu Signed-off-by: Jeff Layton Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman