Payloads of NM entries are not supposed to contain NUL. When we run
into such, only the part prior to the first NUL goes into the
concatenation (i.e. the directory entry name being encoded by a bunch
of NM entries). We do stop when the amount collected so far + the
claimed amount in the current NM entry exceed 254. So far, so good,
but what we return as the total length is the sum of *claimed*
sizes, not the actual amount collected. And that can grow pretty
large - not unlimited, since you'd need to put CE entries in
between to be able to get more than the maximum that could be
contained in one isofs directory entry / continuation chunk and
we are stop once we'd encountered 32 CEs, but you can get about 8Kb
easily. And that's what will be passed to readdir callback as the
name length. 8Kb __copy_to_user() from a buffer allocated by
__get_free_page()
Cc: stable@vger.kernel.org # 0.98pl6+ (yes, really)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
kmap() in page_follow_link_light() needed to go - allowing to hold
an arbitrary number of kmaps for long is a great way to deadlocking
the system.
new helper (inode_nohighmem(inode)) needs to be used for pagecache
symlinks inodes; done for all in-tree cases. page_follow_link_light()
instrumented to yell about anything missed.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
We didn't check length of rock ridge ER records before printing them.
Thus corrupted isofs image can cause us to access and print some memory
behind the buffer with obvious consequences.
Reported-and-tested-by: Carl Henrik Lunde <chlunde@ping.uio.no>
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Rock Ridge extensions define so called Continuation Entries (CE) which
define where is further space with Rock Ridge data. Corrupted isofs
image can contain arbitrarily long chain of these, including a one
containing loop and thus causing kernel to end in an infinite loop when
traversing these entries.
Limit the traversal to 32 entries which should be more than enough space
to store all the Rock Ridge data.
Reported-by: P J P <ppandit@redhat.com>
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
We did not check relocated directory in any way when processing Rock
Ridge 'CL' tag. Thus a corrupted isofs image can possibly have a CL
entry pointing to another CL entry leading to possibly unbounded
recursion in kernel code and thus stack overflow or deadlocks (if there
is a loop created from CL entries).
Fix the problem by not allowing CL entry to point to a directory entry
with CL entry (such use makes no good sense anyway) and by checking
whether CL entry doesn't point to itself.
CC: stable@vger.kernel.org
Reported-by: Chris Evans <cevans@google.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Replace remaining direct i_nlink updates with a new set_nlink()
updater function.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Tested-by: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
sbi->s_mutex isn't needed for isofs at all so we can just remove it. Generally,
since isofs is always mounted read-only, filesystem structure cannot change
under us. So buffer_head contents stays constant after it's filled in. That
leaves us with possible changes of global data structures. Superblock changes
only during filesystem mount (even remount does not change it), inodes are only
filled in during reading from disk. So there are no changes of these structures
to bother about.
Arguments why sbi->s_mutex can be removed at each place:
isofs_readdir: Accesses sb, inode, filp, local variables => s_mutex not needed
isofs_lookup: Protected by directory's i_mutex. Accesses sb, inode, dentry,
local variables => s_mutex not needed
rock_ridge_symlink_readpage: Protected by page lock. Accesses sb, inode,
local variables => s_mutex not needed.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
As in other file systems, we can replace the big kernel lock
with a private mutex in isofs. This means we can now access
multiple file systems concurrently, but it also means that
we serialize readdir and lookup across sleeping operations
which previously released the big kernel lock. This should
not matter though, as these operations are in practice
serialized through the hardware access.
The isofs_get_blocks functions now does not take any lock
any more, it used to recursively get the BKL. After looking
at the code for hours, I convinced myself that it was never
needed here anyway, because it only reads constant fields
of the inode and writes to a buffer head array that is
at this time only visible to the caller.
The get_sb and fill_super operations do not need the locking
at all because they operate on a file system that is either
about to be created or to be destroyed but in either case
is not visible to other threads.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Some iso9660 images contain files with rockridge data that is either
incorrect or incompletely parsed. Prior to commit
f2966632a1 ("[PATCH] rock: handle directory
overflows") (included with kernel 2.6.13) the kernel ignored the rockridge
data for these files, while still allowing the files to be accessed under
their non-rockridge names. That commit inadvertently changed things so
that files with invalid rockridge data could not be accessed at all. (I
ran across the problem when comparing some old CDs with hard disk copies I
had made long ago under kernel 2.4: a few of the files on the hard disk
copies were no longer visible on the CDs.)
This change reverts to the pre-2.6.13 behavior.
Signed-off-by: Adam Greenblatt <adam.greenblatt@gmail.com>
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: <stable@kernel.org> [2.6.25.x, 2.6.26.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Stop the ISOFS filesystem from using read_inode(). Make isofs_read_inode()
return an error code, and make isofs_iget() pass it on.
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Jan Kara <jack@ucw.cz>
Acked-by: Christoph Hellwig <hch@lst.de>
Cc: "Dave Young" <hidave.darkstar@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Same as with already do with the file operations: keep them in .rodata and
prevents people from doing runtime patching.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Steven French <sfrench@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Handle the case where the variable-sized part of a rock-ridge directory entry
overhangs the end of the buffer which we allocated for it.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The bug in rock.c is that it's totally trusting of the contents of the
directories. If the directory says there's a continuation 10000 bytes into
this 4k block then we cheerily poke around in memory we don't own and oops.
So change rock_continue() to apply various sanity checks, at least ensuring
that the offset+length remain within the bounds for the header part of a
struct rock_ridge directory entry.
Note that the kernel can still overindex the buffer due to the variable size
of the rock-ridge directory entries. We cannot check that in rock_continue()
unless we go parse the directory entry's signature and work out its size.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
- remove the MAYBE_CONTINUE macro
- kfree(NULL) is OK.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
- Remove the SETUP_ROCK_RIDGE macro.
- In rock_ridge_symlink_readpage(), rename raw_inode to raw_de. It points
at a directory entry, not an inode.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix stuff which Lindent got wrong, rework a few deeply-nested blocks.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Trying to turn rock.c into something which humans can read so we can fix some
bugs.
Start out by feeding it through scripts/Lindent.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
fs/isofs includes trimmed down to something resembling sanity.
Kernel-only parts of linux/iso_fs.h and entire linux/iso_fs_{sb,i}.h
moved to fs/isofs/isofs.h.
A lot of useless #include in fs/isofs/*.c killed.
Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
