linux.git/net/ceph/mon_client.c, branch for-next

libceph: fix race between delayed_work() and ceph_monc_stop()

2024-07-10T08:11:55+00:00

The way the delayed work is handled in ceph_monc_stop() is prone to
races with mon_fault() and possibly also finish_hunting().  Both of
these can requeue the delayed work which wouldn't be canceled by any of
the following code in case that happens after cancel_delayed_work_sync()
runs -- __close_session() doesn't mess with the delayed work in order
to avoid interfering with the hunting interval logic.  This part was
missed in commit b5d91704f53e ("libceph: behave in mon_fault() if
cur_mon < 0") and use-after-free can still ensue on monc and objects
that hang off of it, with monc->auth and monc->monmap being
particularly susceptible to quickly being reused.

To fix this:

- clear monc->cur_mon and monc->hunting as part of closing the session
  in ceph_monc_stop()
- bail from delayed_work() if monc->cur_mon is cleared, similar to how
  it's done in mon_fault() and finish_hunting() (based on monc->hunting)
- call cancel_delayed_work_sync() after the session is closed

Cc: stable@vger.kernel.org
Link: https://tracker.ceph.com/issues/66857
Signed-off-by: Ilya Dryomov 
Reviewed-by: Xiubo Li

ceph: Annotate struct ceph_monmap with __counted_by

2023-09-18T09:39:29+00:00

Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
(for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

As found with Coccinelle[1], add __counted_by for struct ceph_monmap.
Additionally, since the element count member must be set before accessing
the annotated flexible array member, move its initialization earlier.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc: Ilya Dryomov 
Cc: Xiubo Li 
Cc: Jeff Layton 
Cc: "David S. Miller" 
Cc: Eric Dumazet 
Cc: Jakub Kicinski 
Cc: Paolo Abeni 
Cc: ceph-devel@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook 
Reviewed-by: Gustavo A. R. Silva 
Reviewed-by: Xiubo Li 
Signed-off-by: David S. Miller

treewide: use get_random_u32_below() instead of deprecated function

2022-11-18T01:15:15+00:00

This is a simple mechanical transformation done by:

@@
expression E;
@@
- prandom_u32_max
+ get_random_u32_below
  (E)

Reviewed-by: Kees Cook 
Reviewed-by: Greg Kroah-Hartman 
Acked-by: Darrick J. Wong  # for xfs
Reviewed-by: SeongJae Park  # for damon
Reviewed-by: Jason Gunthorpe  # for infiniband
Reviewed-by: Russell King (Oracle)  # for arm
Acked-by: Ulf Hansson  # for mmc
Signed-off-by: Jason A. Donenfeld

treewide: use prandom_u32_max() when possible, part 1

2022-10-11T23:42:55+00:00

Rather than incurring a division or requesting too many random bytes for
the given range, use the prandom_u32_max() function, which only takes
the minimum required bytes from the RNG and avoids divisions. This was
done mechanically with this coccinelle script:

@basic@
expression E;
type T;
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
typedef u64;
@@
(
- ((T)get_random_u32() % (E))
+ prandom_u32_max(E)
|
- ((T)get_random_u32() & ((E) - 1))
+ prandom_u32_max(E * XXX_MAKE_SURE_E_IS_POW2)
|
- ((u64)(E) * get_random_u32() >> 32)
+ prandom_u32_max(E)
|
- ((T)get_random_u32() & ~PAGE_MASK)
+ prandom_u32_max(PAGE_SIZE)
)

@multi_line@
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
identifier RAND;
expression E;
@@

-       RAND = get_random_u32();
        ... when != RAND
-       RAND %= (E);
+       RAND = prandom_u32_max(E);

// Find a potential literal
@literal_mask@
expression LITERAL;
type T;
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
position p;
@@

        ((T)get_random_u32()@p & (LITERAL))

// Add one to the literal.
@script:python add_one@
literal << literal_mask.LITERAL;
RESULT;
@@

value = None
if literal.startswith('0x'):
        value = int(literal, 16)
elif literal[0] in '123456789':
        value = int(literal, 10)
if value is None:
        print("I don't know how to handle %s" % (literal))
        cocci.include_match(False)
elif value == 2**32 - 1 or value == 2**31 - 1 or value == 2**24 - 1 or value == 2**16 - 1 or value == 2**8 - 1:
        print("Skipping 0x%x for cleanup elsewhere" % (value))
        cocci.include_match(False)
elif value & (value + 1) != 0:
        print("Skipping 0x%x because it's not a power of two minus one" % (value))
        cocci.include_match(False)
elif literal.startswith('0x'):
        coccinelle.RESULT = cocci.make_expr("0x%x" % (value + 1))
else:
        coccinelle.RESULT = cocci.make_expr("%d" % (value + 1))

// Replace the literal mask with the calculated result.
@plus_one@
expression literal_mask.LITERAL;
position literal_mask.p;
expression add_one.RESULT;
identifier FUNC;
@@

-       (FUNC()@p & (LITERAL))
+       prandom_u32_max(RESULT)

@collapse_ret@
type T;
identifier VAR;
expression E;
@@

 {
-       T VAR;
-       VAR = (E);
-       return VAR;
+       return E;
 }

@drop_var@
type T;
identifier VAR;
@@

 {
-       T VAR;
        ... when != VAR
 }

Reviewed-by: Greg Kroah-Hartman 
Reviewed-by: Kees Cook 
Reviewed-by: Yury Norov 
Reviewed-by: KP Singh 
Reviewed-by: Jan Kara  # for ext4 and sbitmap
Reviewed-by: Christoph Böhmwalder  # for drbd
Acked-by: Jakub Kicinski 
Acked-by: Heiko Carstens  # for s390
Acked-by: Ulf Hansson  # for mmc
Acked-by: Darrick J. Wong  # for xfs
Signed-off-by: Jason A. Donenfeld

libceph: drop ->monmap and err initialization

2021-11-08T02:29:51+00:00

Call to build_initial_monmap() is one stone two birds.  Explicitly it
initializes err variable. Implicitly it initializes ->monmap via call to
kzalloc().  We should only declare err and ->monmap is taken care of by
ceph_monc_init() prototype.

Signed-off-by: Jean Sacren 
Reviewed-by: Ilya Dryomov 
Signed-off-by: Ilya Dryomov

libceph: Fix spelling mistakes

2021-06-03T20:24:23+00:00

Fix some spelling mistakes in comments:
enconding  ==> encoding
ambigous  ==> ambiguous
orignal  ==> original
encyption  ==> encryption

Signed-off-by: Zheng Yongjun 
Signed-off-by: David S. Miller

libceph, ceph: disambiguate ceph_connection_operations handlers

2021-01-04T16:31:32+00:00

Since a few years, kernel addresses are no longer included in oops
dumps, at least on x86.  All we get is a symbol name with offset and
size.

This is a problem for ceph_connection_operations handlers, especially
con->ops->dispatch().  All three handlers have the same name and there
is little context to disambiguate between e.g. monitor and OSD clients
because almost everything is inlined.  gdb sneakily stops at the first
matching symbol, so one has to resort to nm and addr2line.

Some of these are already prefixed with mon_, osd_ or mds_.  Let's do
the same for all others.

Signed-off-by: Ilya Dryomov 
Acked-by: Jeff Layton

libceph, ceph: implement msgr2.1 protocol (crc and secure modes)

2020-12-14T22:21:50+00:00

Implement msgr2.1 wire protocol, available since nautilus 14.2.11
and octopus 15.2.5.  msgr2.0 wire protocol is not implemented -- it
has several security, integrity and robustness issues and therefore
considered deprecated.

Signed-off-by: Ilya Dryomov

libceph: introduce connection modes and ms_mode option

2020-12-14T22:21:50+00:00

msgr2 supports two connection modes: crc (plain) and secure (on-wire
encryption).  Connection mode is picked by server based on input from
client.

Introduce ms_mode option:

  ms_mode=legacy        - msgr1 (default)
  ms_mode=crc           - crc mode, if denied fail
  ms_mode=secure        - secure mode, if denied fail
  ms_mode=prefer-crc    - crc mode, if denied agree to secure mode
  ms_mode=prefer-secure - secure mode, if denied agree to crc mode

ms_mode affects all connections, we don't separate connections to mons
like it's done in userspace with ms_client_mode vs ms_mon_client_mode.

For now the default is legacy, to be flipped to prefer-crc after some
time.

Signed-off-by: Ilya Dryomov

libceph, rbd: ignore addr->type while comparing in some cases

2020-12-14T22:21:50+00:00

For libceph, this ensures that libceph instance sharing (share option)
continues to work.  For rbd, this avoids blocklisting alive lock owners
(locker addr is always LEGACY, while watcher addr is ANY in nautilus).

Signed-off-by: Ilya Dryomov