kernel/linux.git/net/ceph/mon_client.c, branch v6.6.148

libceph: Reject monmaps advertising zero monitors

2026-08-03T09:15:29+00:00

commit 40480eee361ed9676b3f844d532ac28b47251634 upstream. A message of type CEPH_MSG_MON_MAP contains a monmap that is sent from a monitor to the client. This monmap contains information about the existing monitors in the cluster. Currently, a monmap indicating that there are zero monitors in the cluster is treated as valid. However, it is impossible to have zero monitors in the cluster and still receive a valid monmap from a monitor. Therefore, such a monmap must be corrupted and should be treated as invalid. Furthermore, a monmap with a monitor count of zero can subsequently crash the client when attempting to open a session with a monitor in __open_session(). This happens because the "BUG_ON(monc->monmap->num_mon < 1)" assertion in pick_new_mon() is triggered. This patch extends a check in ceph_monmap_decode() to also reject arriving mon_maps with num_mon == 0 rather than only with num_mon > CEPH_MAX_MON. [ idryomov: drop "log output for unusual values of num_mon" part ] Cc: stable@vger.kernel.org Signed-off-by: Raphael Zimmer Reviewed-by: Ilya Dryomov Signed-off-by: Ilya Dryomov Signed-off-by: Greg Kroah-Hartman

libceph: bound get_version reply decode to front len

2026-08-03T09:15:29+00:00

commit d3c32939fa0e3ee9b883b9a0fd1972c5c444e3d0 upstream. handle_get_version_reply() uses msg->front_alloc_len as the decode boundary for MON_GET_VERSION_REPLY. That is the size of the reused reply buffer, not the number of bytes actually received. A truncated reply can therefore pass ceph_decode_need() and decode the second u64 from stale tail bytes left in the buffer by an earlier message, causing an uninitialized memory read. Use msg->front.iov_len as the receive-side decode boundary, matching other libceph reply handlers and limiting decoding to the bytes that were actually read from the wire. Cc: stable@vger.kernel.org Fixes: 513a8243d67f ("libceph: mon_get_version request infrastructure") Reported-by: Yuan Tan Reported-by: Zhengchuan Liang Reported-by: Xin Liu Assisted-by: Codex:GPT-5.4 Signed-off-by: Douya Le Signed-off-by: Ren Wei Reviewed-by: Viacheslav Dubeyko Signed-off-by: Ilya Dryomov Signed-off-by: Greg Kroah-Hartman

libceph: Fix slab-out-of-bounds access in auth message processing

2026-05-17T15:13:41+00:00

commit 1c439de70b1c3eb3c6bffa8245c16b9fc318f114 upstream. If a (potentially corrupted) message of type CEPH_MSG_AUTH_REPLY contains a positive value in its result field, it is treated as an error code by ceph_handle_auth_reply() and returned to handle_auth_reply(). Thereafter, an attempt is made to send the preallocated message of type CEPH_MSG_AUTH, where the returned value is interpreted as the size of the front segment to send. If the result value in the message is greater than the size of the memory buffer allocated for the front segment, an out-of-bounds access occurs, and the content of the memory region beyond this buffer is sent out. This patch fixes the issue by treating only negative values in the result field as errors. Positive values are therefore treated as success in the same way as a zero value. Additionally, a BUG_ON is added to __send_prepared_auth_request() comparing the len parameter to front_alloc_len to prevent sending the message if it exceeds the bounds of the allocation and to make it easier to catch any logic flaws leading to this. Cc: stable@vger.kernel.org Signed-off-by: Raphael Zimmer Reviewed-by: Ilya Dryomov Signed-off-by: Ilya Dryomov Signed-off-by: Greg Kroah-Hartman

libceph: Use u32 for non-negative values in ceph_monmap_decode()

2026-03-25T10:05:50+00:00

commit 770444611f047dbfd4517ec0bc1b179d40c2f346 upstream. This patch fixes unnecessary implicit conversions that change signedness of blob_len and num_mon in ceph_monmap_decode(). Currently blob_len and num_mon are (signed) int variables. They are used to hold values that are always non-negative and get assigned in ceph_decode_32_safe(), which is meant to assign u32 values. Both variables are subsequently used as unsigned values, and the value of num_mon is further assigned to monmap->num_mon, which is of type u32. Therefore, both variables should be of type u32. This is especially relevant for num_mon. If the value read from the incoming message is very large, it is interpreted as a negative value, and the check for num_mon > CEPH_MAX_MON does not catch it. This leads to the attempt to allocate a very large chunk of memory for monmap, which will most likely fail. In this case, an unnecessary attempt to allocate memory is performed, and -ENOMEM is returned instead of -EINVAL. Cc: stable@vger.kernel.org Signed-off-by: Raphael Zimmer Reviewed-by: Viacheslav Dubeyko Reviewed-by: Ilya Dryomov Signed-off-by: Ilya Dryomov Signed-off-by: Greg Kroah-Hartman

libceph: return the handler error from mon_handle_auth_done()

2026-01-17T15:29:54+00:00

commit e84b48d31b5008932c0a0902982809fbaa1d3b70 upstream. Currently any error from ceph_auth_handle_reply_done() is propagated via finish_auth() but isn't returned from mon_handle_auth_done(). This results in higher layers learning that (despite the monitor considering us to be successfully authenticated) something went wrong in the authentication phase and reacting accordingly, but msgr2 still trying to proceed with establishing the session in the background. In the case of secure mode this can trigger a WARN in setup_crypto() and later lead to a NULL pointer dereference inside of prepare_auth_signature(). Cc: stable@vger.kernel.org Fixes: cd1a677cad99 ("libceph, ceph: implement msgr2.1 protocol (crc and secure modes)") Signed-off-by: Ilya Dryomov Reviewed-by: Viacheslav Dubeyko Signed-off-by: Greg Kroah-Hartman

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

2024-07-18T11:21:22+00:00

commit 69c7b2fe4c9cc1d3b1186d1c5606627ecf0de883 upstream. 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 Signed-off-by: Greg Kroah-Hartman

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