skb_can_coalesce() allows coalescing neighboring slab objects into
a single frag:
return page == skb_frag_page(frag) &&
off == frag->page_offset + skb_frag_size(frag);
ceph_tcp_sendpage() can be handed slab pages. One example of this is
XFS: it passes down sector sized slab objects for its metadata I/O. If
the kernel client is co-located on the OSD node, the skb may go through
loopback and pop on the receive side with the exact same set of frags.
When tcp_recvmsg() attempts to copy out such a frag, hardened usercopy
complains because the size exceeds the object's allocated size:
usercopy: kernel memory exposure attempt detected from ffff9ba917f20a00 (kmalloc-512) (1024 bytes)
Although skb_can_coalesce() could be taught to return false if the
resulting frag would cross a slab object boundary, we already have
a fallback for non-refcounted pages. Utilize it for slab pages too.
Cc: stable@vger.kernel.org # 4.8+
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Pull AFS updates from Al Viro:
"AFS series, with some iov_iter bits included"
* 'work.afs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (26 commits)
missing bits of "iov_iter: Separate type from direction and use accessor functions"
afs: Probe multiple fileservers simultaneously
afs: Fix callback handling
afs: Eliminate the address pointer from the address list cursor
afs: Allow dumping of server cursor on operation failure
afs: Implement YFS support in the fs client
afs: Expand data structure fields to support YFS
afs: Get the target vnode in afs_rmdir() and get a callback on it
afs: Calc callback expiry in op reply delivery
afs: Fix FS.FetchStatus delivery from updating wrong vnode
afs: Implement the YFS cache manager service
afs: Remove callback details from afs_callback_break struct
afs: Commit the status on a new file/dir/symlink
afs: Increase to 64-bit volume ID and 96-bit vnode ID for YFS
afs: Don't invoke the server to read data beyond EOF
afs: Add a couple of tracepoints to log I/O errors
afs: Handle EIO from delivery function
afs: Fix TTL on VL server and address lists
afs: Implement VL server rotation
afs: Improve FS server rotation error handling
...
Pull ceph updates from Ilya Dryomov:
"The highlights are:
- a series that fixes some old memory allocation issues in libceph
(myself). We no longer allocate memory in places where allocation
failures cannot be handled and BUG when the allocation fails.
- support for copy_file_range() syscall (Luis Henriques). If size and
alignment conditions are met, it leverages RADOS copy-from
operation. Otherwise, a local copy is performed.
- a patch that reduces memory requirement of ceph_sync_read() from
the size of the entire read to the size of one object (Zheng Yan).
- fallocate() syscall is now restricted to FALLOC_FL_PUNCH_HOLE (Luis
Henriques)"
* tag 'ceph-for-4.20-rc1' of git://github.com/ceph/ceph-client: (25 commits)
ceph: new mount option to disable usage of copy-from op
ceph: support copy_file_range file operation
libceph: support the RADOS copy-from operation
ceph: add non-blocking parameter to ceph_try_get_caps()
libceph: check reply num_data_items in setup_request_data()
libceph: preallocate message data items
libceph, rbd, ceph: move ceph_osdc_alloc_messages() calls
libceph: introduce alloc_watch_request()
libceph: assign cookies in linger_submit()
libceph: enable fallback to ceph_msg_new() in ceph_msgpool_get()
ceph: num_ops is off by one in ceph_aio_retry_work()
libceph: no need to call osd_req_opcode_valid() in osd_req_encode_op()
ceph: set timeout conditionally in __cap_delay_requeue
libceph: don't consume a ref on pagelist in ceph_msg_data_add_pagelist()
libceph: introduce ceph_pagelist_alloc()
libceph: osd_req_op_cls_init() doesn't need to take opcode
libceph: bump CEPH_MSG_MAX_DATA_LEN
ceph: only allow punch hole mode in fallocate
ceph: refactor ceph_sync_read()
ceph: check if LOOKUPNAME request was aborted when filling trace
...
In the iov_iter struct, separate the iterator type from the iterator
direction and use accessor functions to access them in most places.
Convert a bunch of places to use switch-statements to access them rather
then chains of bitwise-AND statements. This makes it easier to add further
iterator types. Also, this can be more efficient as to implement a switch
of small contiguous integers, the compiler can use ~50% fewer compare
instructions than it has to use bitwise-and instructions.
Further, cease passing the iterator type into the iterator setup function.
The iterator function can set that itself. Only the direction is required.
Signed-off-by: David Howells <dhowells@redhat.com>
Add support for performing remote object copies using the 'copy-from'
operation.
[ Add COPY_FROM to get_num_data_items(). ]
Signed-off-by: Luis Henriques <lhenriques@suse.com>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
setup_request_data() adds message data items to both request and reply
messages, but only checks request num_data_items before proceeding with
the loop. This is wrong because if an op doesn't have any request data
items but has a reply data item (e.g. read), a duplicate data item gets
added to the message on every resend attempt.
This went unnoticed for years but now that message data items are
preallocated, it promptly crashes in ceph_msg_data_add(). Amend the
signature to make it clear that setup_request_data() operates on both
request and reply messages. Also, remove data_len assert -- we have
another one in prepare_write_message().
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Currently message data items are allocated with ceph_msg_data_create()
in setup_request_data() inside send_request(). send_request() has never
been allowed to fail, so each allocation is followed by a BUG_ON:
data = ceph_msg_data_create(...);
BUG_ON(!data);
It's been this way since support for multiple message data items was
added in commit 6644ed7b7e ("libceph: make message data be a pointer")
in 3.10.
There is no reason to delay the allocation of message data items until
the last possible moment and we certainly don't need a linked list of
them as they are only ever appended to the end and never erased. Make
ceph_msg_new2() take max_data_items and adapt the rest of the code.
Reported-by: Jerry Lee <leisurelysw24@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
The current requirement is that ceph_osdc_alloc_messages() should be
called after oid and oloc are known. In preparation for preallocating
message data items, move ceph_osdc_alloc_messages() further down, so
that it is called when OSD op codes are known.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
ceph_osdc_alloc_messages() call will be moved out of
alloc_linger_request() in the next commit, which means that
ceph_osdc_watch() will need to call ceph_osdc_alloc_messages()
twice. Add a helper for that.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Register lingers directly in linger_submit(). This avoids allocating
memory for notify pagelist while holding osdc->lock and simplifies both
callers of linger_submit().
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
ceph_msgpool_get() can fall back to ceph_msg_new() when it is asked for
a message whose front portion is larger than pool->front_len. However
the caller always passes 0, effectively disabling that code path. The
allocation goes to the message pool and returns a message with a front
that is smaller than requested, setting us up for a crash.
One example of this is a directory with a large number of snapshots.
If its snap context doesn't fit, we oops in encode_request_partial().
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Because send_mds_reconnect() wants to send a message with a pagelist
and pass the ownership to the messenger, ceph_msg_data_add_pagelist()
consumes a ref which is then put in ceph_msg_data_destroy(). This
makes managing pagelists in the OSD client (where they are wrapped in
ceph_osd_data) unnecessarily hard because the handoff only happens in
ceph_osdc_start_request() instead of when the pagelist is passed to
ceph_osd_data_pagelist_init(). I counted several memory leaks on
various error paths.
Fix up ceph_msg_data_add_pagelist() and carry a pagelist ref in
ceph_osd_data.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
struct ceph_pagelist cannot be embedded into anything else because it
has its own refcount. Merge allocation and initialization together.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Avoid scribbling over memory if the received reply/challenge is larger
than the buffer supplied with the authorizer.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Sage Weil <sage@redhat.com>
Derive the signature from the entire buffer (both AES cipher blocks)
instead of using just the first half of the first block, leaving out
data_crc entirely.
This addresses CVE-2018-1129.
Link: http://tracker.ceph.com/issues/24837
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Sage Weil <sage@redhat.com>
When a client authenticates with a service, an authorizer is sent with
a nonce to the service (ceph_x_authorize_[ab]) and the service responds
with a mutation of that nonce (ceph_x_authorize_reply). This lets the
client verify the service is who it says it is but it doesn't protect
against a replay: someone can trivially capture the exchange and reuse
the same authorizer to authenticate themselves.
Allow the service to reject an initial authorizer with a random
challenge (ceph_x_authorize_challenge). The client then has to respond
with an updated authorizer proving they are able to decrypt the
service's challenge and that the new authorizer was produced for this
specific connection instance.
The accepting side requires this challenge and response unconditionally
if the client side advertises they have CEPHX_V2 feature bit.
This addresses CVE-2018-1128.
Link: http://tracker.ceph.com/issues/24836
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Sage Weil <sage@redhat.com>
Will be used for encrypting both the initial and updated authorizers.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Sage Weil <sage@redhat.com>
Will be used for decrypting the server challenge which is only preceded
by ceph_x_encrypt_header.
Drop struct_v check to allow for extending ceph_x_encrypt_header in the
future.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Sage Weil <sage@redhat.com>
Will be used for sending ceph_msg_connect with an updated authorizer,
after the server challenges the initial authorizer.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Sage Weil <sage@redhat.com>
Ilya Dryomov
Linus Torvalds
David Howells
Luis Henriques
Kees Cook
YueHaibing