user/sven/linux.git/fs, branch v3.14.36

NFSv4: Don't call put_rpccred() under the rcu_read_lock()

2015-03-18T12:31:34Z

commit 7c0af9ffb7bb4e5355470fa60b3eb711ddf226fa upstream. put_rpccred() can sleep. Fixes: 8f649c3762547 ("NFSv4: Fix the locking in nfs_inode_reclaim_delegation()") Signed-off-by: Trond Myklebust Signed-off-by: Greg Kroah-Hartman

nilfs2: fix potential memory overrun on inode

2015-03-18T12:31:32Z

commit 957ed60b53b519064a54988c4e31e0087e47d091 upstream. Each inode of nilfs2 stores a root node of a b-tree, and it turned out to have a memory overrun issue: Each b-tree node of nilfs2 stores a set of key-value pairs and the number of them (in "bn_nchildren" member of nilfs_btree_node struct), as well as a few other "bn_*" members. Since the value of "bn_nchildren" is used for operations on the key-values within the b-tree node, it can cause memory access overrun if a large number is incorrectly set to "bn_nchildren". For instance, nilfs_btree_node_lookup() function determines the range of binary search with it, and too large "bn_nchildren" leads nilfs_btree_node_get_key() in that function to overrun. As for intermediate b-tree nodes, this is prevented by a sanity check performed when each node is read from a drive, however, no sanity check has been done for root nodes stored in inodes. This patch fixes the issue by adding missing sanity check against b-tree root nodes so that it's called when on-memory inodes are read from ifile, inode metadata file. Signed-off-by: Ryusuke Konishi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

procfs: fix race between symlink removals and traversals

2015-03-18T12:31:31Z

commit 7e0e953bb0cf649f93277ac8fb67ecbb7f7b04a9 upstream. use_pde()/unuse_pde() in ->follow_link()/->put_link() resp. Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman

debugfs: leave freeing a symlink body until inode eviction

2015-03-18T12:31:30Z

commit 0db59e59299f0b67450c5db21f7f316c8fb04e84 upstream. As it is, we have debugfs_remove() racing with symlink traversals. Supply ->evict_inode() and do freeing there - inode will remain pinned until we are done with the symlink body. And rip the idiocy with checking if dentry is positive right after we'd verified debugfs_positive(), which is a stronger check... Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman

autofs4 copy_dev_ioctl(): keep the value of ->size we'd used for allocation

2015-03-18T12:31:30Z

commit 0a280962dc6e117e0e4baa668453f753579265d9 upstream. X-Coverup: just ask spender Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman

Btrfs:__add_inode_ref: out of bounds memory read when looking for extended ref.

2015-03-18T12:31:27Z

commit dd9ef135e3542ffc621c4eb7f0091870ec7a1504 upstream. Improper arithmetics when calculting the address of the extended ref could lead to an out of bounds memory read and kernel panic. Signed-off-by: Quentin Casasnovas Reviewed-by: David Sterba Signed-off-by: Chris Mason Signed-off-by: Greg Kroah-Hartman

Btrfs: fix data loss in the fast fsync path

2015-03-18T12:31:27Z

commit 3a8b36f378060d20062a0918e99fae39ff077bf0 upstream. When using the fast file fsync code path we can miss the fact that new writes happened since the last file fsync and therefore return without waiting for the IO to finish and write the new extents to the fsync log. Here's an example scenario where the fsync will miss the fact that new file data exists that wasn't yet durably persisted: 1. fs_info->last_trans_committed == N - 1 and current transaction is transaction N (fs_info->generation == N); 2. do a buffered write; 3. fsync our inode, this clears our inode's full sync flag, starts an ordered extent and waits for it to complete - when it completes at btrfs_finish_ordered_io(), the inode's last_trans is set to the value N (via btrfs_update_inode_fallback -> btrfs_update_inode -> btrfs_set_inode_last_trans); 4. transaction N is committed, so fs_info->last_trans_committed is now set to the value N and fs_info->generation remains with the value N; 5. do another buffered write, when this happens btrfs_file_write_iter sets our inode's last_trans to the value N + 1 (that is fs_info->generation + 1 == N + 1); 6. transaction N + 1 is started and fs_info->generation now has the value N + 1; 7. transaction N + 1 is committed, so fs_info->last_trans_committed is set to the value N + 1; 8. fsync our inode - because it doesn't have the full sync flag set, we only start the ordered extent, we don't wait for it to complete (only in a later phase) therefore its last_trans field has the value N + 1 set previously by btrfs_file_write_iter(), and so we have: inode->last_trans <= fs_info->last_trans_committed (N + 1) (N + 1) Which made us not log the last buffered write and exit the fsync handler immediately, returning success (0) to user space and resulting in data loss after a crash. This can actually be triggered deterministically and the following excerpt from a testcase I made for xfstests triggers the issue. It moves a dummy file across directories and then fsyncs the old parent directory - this is just to trigger a transaction commit, so moving files around isn't directly related to the issue but it was chosen because running 'sync' for example does more than just committing the current transaction, as it flushes/waits for all file data to be persisted. The issue can also happen at random periods, since the transaction kthread periodicaly commits the current transaction (about every 30 seconds by default). The body of the test is: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our main test file 'foo', the one we check for data loss. # By doing an fsync against our file, it makes btrfs clear the 'needs_full_sync' # bit from its flags (btrfs inode specific flags). $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 8K" \ -c "fsync" $SCRATCH_MNT/foo | _filter_xfs_io # Now create one other file and 2 directories. We will move this second file # from one directory to the other later because it forces btrfs to commit its # currently open transaction if we fsync the old parent directory. This is # necessary to trigger the data loss bug that affected btrfs. mkdir $SCRATCH_MNT/testdir_1 touch $SCRATCH_MNT/testdir_1/bar mkdir $SCRATCH_MNT/testdir_2 # Make sure everything is durably persisted. sync # Write more 8Kb of data to our file. $XFS_IO_PROG -c "pwrite -S 0xbb 8K 8K" $SCRATCH_MNT/foo | _filter_xfs_io # Move our 'bar' file into a new directory. mv $SCRATCH_MNT/testdir_1/bar $SCRATCH_MNT/testdir_2/bar # Fsync our first directory. Because it had a file moved into some other # directory, this made btrfs commit the currently open transaction. This is # a condition necessary to trigger the data loss bug. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/testdir_1 # Now fsync our main test file. If the fsync succeeds, we expect the 8Kb of # data we wrote previously to be persisted and available if a crash happens. # This did not happen with btrfs, because of the transaction commit that # happened when we fsynced the parent directory. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Now check that all data we wrote before are available. echo "File content after log replay:" od -t x1 $SCRATCH_MNT/foo status=0 exit The expected golden output for the test, which is what we get with this fix applied (or when running against ext3/4 and xfs), is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 8192/8192 bytes at offset 8192 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb * 0040000 Without this fix applied, the output shows the test file does not have the second 8Kb extent that we successfully fsynced: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 8192/8192 bytes at offset 8192 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 So fix this by skipping the fsync only if we're doing a full sync and if the inode's last_trans is <= fs_info->last_trans_committed, or if the inode is already in the log. Also remove setting the inode's last_trans in btrfs_file_write_iter since it's useless/unreliable. Also because btrfs_file_write_iter no longer sets inode->last_trans to fs_info->generation + 1, don't set last_trans to 0 if we bail out and don't bail out if last_trans is 0, otherwise something as simple as the following example wouldn't log the second write on the last fsync: 1. write to file 2. fsync file 3. fsync file |--> btrfs_inode_in_log() returns true and it set last_trans to 0 4. write to file |--> btrfs_file_write_iter() no longers sets last_trans, so it remained with a value of 0 5. fsync |--> inode->last_trans == 0, so it bails out without logging the second write A test case for xfstests will be sent soon. Signed-off-by: Filipe Manana Signed-off-by: Chris Mason Signed-off-by: Greg Kroah-Hartman

btrfs: fix lost return value due to variable shadowing

2015-03-18T12:31:27Z

commit 1932b7be973b554ffe20a5bba6ffaed6fa995cdc upstream. A block-local variable stores error code but btrfs_get_blocks_direct may not return it in the end as there's a ret defined in the function scope. Fixes: d187663ef24c ("Btrfs: lock extents as we map them in DIO") Signed-off-by: David Sterba Signed-off-by: Chris Mason Signed-off-by: Greg Kroah-Hartman

x86, mm/ASLR: Fix stack randomization on 64-bit systems

2015-03-06T22:43:32Z

commit 4e7c22d447bb6d7e37bfe39ff658486ae78e8d77 upstream. The issue is that the stack for processes is not properly randomized on 64 bit architectures due to an integer overflow. The affected function is randomize_stack_top() in file "fs/binfmt_elf.c": static unsigned long randomize_stack_top(unsigned long stack_top) { unsigned int random_variable = 0; if ((current->flags & PF_RANDOMIZE) && !(current->personality & ADDR_NO_RANDOMIZE)) { random_variable = get_random_int() & STACK_RND_MASK; random_variable <<= PAGE_SHIFT; } return PAGE_ALIGN(stack_top) + random_variable; return PAGE_ALIGN(stack_top) - random_variable; } Note that, it declares the "random_variable" variable as "unsigned int". Since the result of the shifting operation between STACK_RND_MASK (which is 0x3fffff on x86_64, 22 bits) and PAGE_SHIFT (which is 12 on x86_64): random_variable <<= PAGE_SHIFT; then the two leftmost bits are dropped when storing the result in the "random_variable". This variable shall be at least 34 bits long to hold the (22+12) result. These two dropped bits have an impact on the entropy of process stack. Concretely, the total stack entropy is reduced by four: from 2^28 to 2^30 (One fourth of expected entropy). This patch restores back the entropy by correcting the types involved in the operations in the functions randomize_stack_top() and stack_maxrandom_size(). The successful fix can be tested with: $ for i in `seq 1 10`; do cat /proc/self/maps | grep stack; done 7ffeda566000-7ffeda587000 rw-p 00000000 00:00 0 [stack] 7fff5a332000-7fff5a353000 rw-p 00000000 00:00 0 [stack] 7ffcdb7a1000-7ffcdb7c2000 rw-p 00000000 00:00 0 [stack] 7ffd5e2c4000-7ffd5e2e5000 rw-p 00000000 00:00 0 [stack] ... Once corrected, the leading bytes should be between 7ffc and 7fff, rather than always being 7fff. Signed-off-by: Hector Marco-Gisbert Signed-off-by: Ismael Ripoll [ Rebased, fixed 80 char bugs, cleaned up commit message, added test example and CVE ] Signed-off-by: Kees Cook Cc: Linus Torvalds Cc: Andrew Morton Cc: Al Viro Fixes: CVE-2015-1593 Link: http://lkml.kernel.org/r/20150214173350.GA18393@www.outflux.net Signed-off-by: Borislav Petkov Signed-off-by: Greg Kroah-Hartman

btrfs: fix leak of path in btrfs_find_item

2015-03-06T22:43:32Z

commit 381cf6587f8a8a8e981bc0c1aaaa8859b51dc756 upstream. If btrfs_find_item is called with NULL path it allocates one locally but does not free it. Affected paths are inserting an orphan item for a file and for a subvol root. Move the path allocation to the callers. Fixes: 3f870c289900 ("btrfs: expand btrfs_find_item() to include find_orphan_item functionality") Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman