kernel/linux.git/net/ceph/osdmap.c, branch v6.1.186

libceph: bound pg_{temp,upmap,upmap_items} length to CEPH_PG_MAX_SIZE

2026-08-23T12:18:31+00:00

[ Upstream commit 9f00f9cf2be293efe899db67dc5272e3a9c62717 ] __decode_pg_temp() decodes an user-controlled length but only rejects values large enough to overflow the allocation; it does not bound it to CEPH_PG_MAX_SIZE. The helper backs both pg_temp and pg_upmap decoding, and apply_upmap()/get_temp_osds() later copy the decoded list into the fixed-size on-stack array struct ceph_osds.osds[CEPH_PG_MAX_SIZE]. A monitor that sends an OSDMap with a pg_temp/pg_upmap entry longer than 32 thus causes a stack out-of-bounds write. An OSD set for a single PG can never exceed CEPH_PG_MAX_SIZE, so reject longer entries at decode time. The bound is well below the old overflow threshold, so it also covers the allocation-size overflow the previous check guarded against. BUG: KASAN: stack-out-of-bounds in ceph_pg_to_up_acting_osds Write of size 4 ... by task exploit kasan_report (mm/kasan/report.c:595) ceph_pg_to_up_acting_osds (net/ceph/osdmap.c:2617 net/ceph/osdmap.c:2833) calc_target (net/ceph/osd_client.c:1638) __submit_request (net/ceph/osd_client.c:2394) ceph_osdc_start_request (net/ceph/osd_client.c:2490) ceph_osdc_call (net/ceph/osd_client.c:5164) rbd_dev_image_probe (drivers/block/rbd.c:6899) do_rbd_add (drivers/block/rbd.c:7138) ... kernel BUG at net/ceph/osdmap.c:2670! [ idryomov: do the same in __decode_pg_upmap_items() ] Cc: stable@vger.kernel.org Fixes: a303bb0e5834 ("libceph: introduce and switch to decode_pg_mapping()") Reported-by: Weiming Shi Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Xiang Mei Reviewed-by: Alex Markuze Signed-off-by: Ilya Dryomov Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

libceph: Amend checking to fix `make W=1` build breakage

2026-08-23T12:18:31+00:00

[ Upstream commit 04d8712b079327409b09dee628378f9583e2e035 ] In a few cases the code compares 32-bit value to a SIZE_MAX derived constant which is much higher than that value on 64-bit platforms, Clang, in particular, is not happy about this net/ceph/osdmap.c:1441:10: error: result of comparison of constant 4611686018427387891 with expression of type 'u32' (aka 'unsigned int') is always false [-Werror,-Wtautological-constant-out-of-range-compare] 1441 | if (len > (SIZE_MAX - sizeof(*pg)) / sizeof(u32)) | ~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ net/ceph/osdmap.c:1624:10: error: result of comparison of constant 2305843009213693945 with expression of type 'u32' (aka 'unsigned int') is always false [-Werror,-Wtautological-constant-out-of-range-compare] 1624 | if (len > (SIZE_MAX - sizeof(*pg)) / (2 * sizeof(u32))) | ~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Fix this by casting to size_t. Note, that possible replacement of SIZE_MAX by U32_MAX may lead to the behaviour changes on the corner cases. Signed-off-by: Andy Shevchenko Reviewed-by: Viacheslav Dubeyko Signed-off-by: Ilya Dryomov Stable-dep-of: 9f00f9cf2be2 ("libceph: bound pg_{temp,upmap,upmap_items} length to CEPH_PG_MAX_SIZE") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

libceph: Avoid using invalid osd indices from primary_temp

2026-08-23T12:18:19+00:00

commit 3660b98d1204b419f6a77e9a295f148dcf38d042 upstream. A corrupted osdmap received from a Ceph monitor or OSD may contain osd indices in its pg_temp, primary_temp, pg_upmap, and pg_upmap_items parts that don't exist, i.e., that are greater than max_osd or smaller than CEPH_HOMELESS_OSD (-1). These indices are used to create the up and acting set in ceph_pg_to_up_acting_osds(), called from calc_target(). While most of these osd indices are checked, the one from primary_temp is not. Subsequently, this may lead to calc_target() returning this (potentially invalid) index as target osd for a (linger) request. Because the osd_state, osd_weight, and osd_addr arrays only contain max_osd entries (with indices 0 to max_osd -1), this leads to out-of-bounds accesses when trying to read values from these arrays. This patch fixes the issue by adding a check to get_temp_osds(), so that only valid osd indices from primary_temp are used, and it falls back to using the primary from pg_temp or the up set if it is invalid. [ idryomov: changelog ] Cc: stable@vger.kernel.org Fixes: 5e8d4d36bf23 ("libceph: add support for primary_temp mappings") Signed-off-by: Raphael Zimmer Reviewed-by: Ilya Dryomov Signed-off-by: Ilya Dryomov Signed-off-by: Greg Kroah-Hartman

libceph: reject zero bucket types in crush_decode

2026-08-19T15:16:08+00:00

commit 05f90284223381005d6bcddab3fda4a97f9c3401 upstream. CRUSH bucket type 0 is reserved for devices. The mapper relies on that invariant and uses type 0 to identify leaf devices. If crush_decode() accepts a bucket with type 0, a malformed CRUSH map can make the mapper treat a negative bucket ID as a device and pass it to is_out(), which then indexes the OSD weight array with a negative value. Reject zero bucket types while decoding the CRUSH map so the invalid state never reaches the mapper. Cc: stable@vger.kernel.org Fixes: f24e9980eb86 ("ceph: OSD client") 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: Ilya Dryomov Signed-off-by: Ilya Dryomov Signed-off-by: Greg Kroah-Hartman

libceph: guard missing CRUSH type name lookup

2026-08-19T15:16:07+00:00

commit bbeae12fda3384a90fbebc8a19ba9d33f85b5361 upstream. Localized read selection can walk a parent bucket whose name exists in the CRUSH map while its type has no matching entry in type_names. get_immediate_parent() then dereferences a NULL type_cn and passes an invalid pointer into strcmp(), causing a null-ptr-deref. Skip such malformed parent buckets unless both the bucket name and type name metadata are present. This keeps malformed hierarchy data from crashing locality lookup and safely falls back to "not local". [ idryomov: add WARN_ON_ONCE ] Cc: stable@vger.kernel.org Fixes: 117d96a04f00 ("libceph: support for balanced and localized reads") Reported-by: Yuan Tan Reported-by: Zhengchuan Liang Reported-by: Xin Liu Assisted-by: Codex:GPT-5.4 Signed-off-by: Zhao Zhang Signed-off-by: Ren Wei Reviewed-by: Viacheslav Dubeyko Signed-off-by: Ilya Dryomov Signed-off-by: Greg Kroah-Hartman

libceph: Fix multiplication overflow in decode_new_up_state_weight()

2026-08-19T15:16:07+00:00

commit 98917a499ec7064c14fc56d180a4fd636fc2784c upstream. If a message of type CEPH_MSG_OSD_MAP contains a (maliciously) corrupted osdmap, out-of-bounds memory accesses may occur in decode_new_up_state_weight(). This happens because the bounds check for the new_state part is based on calculating its length depending on a len value read from the incoming message. This calculation may overflow leading to an incorrect bounds check. Subsequently, out-of-bounds reads may occur when decoding this part. This patch switches the multiplication to use check_mul_overflow() to abort processing the osdmap if an overflow occurred. Therefore, osdmaps/messages containing large values for len that result in a multiplication overflow are treated as invalid. [ idryomov: rename new_state_len -> new_state_item_size, formatting ] Cc: stable@vger.kernel.org Fixes: 930c53286977 ("libceph: apply new_state before new_up_client on incrementals") Signed-off-by: Raphael Zimmer Reviewed-by: Viacheslav Dubeyko Signed-off-by: Ilya Dryomov Signed-off-by: Greg Kroah-Hartman

libceph: handle rbtree insertion error in decode_choose_args()

2026-06-01T15:39:33+00:00

commit d289478cfc0bcf81c7914200d6abdcb78bd04ded upstream. A message of type CEPH_MSG_OSD_MAP contains an OSD map that itself contains a CRUSH map. The received CRUSH map may optionally contain choose_args that get decoded in decode_choose_args(). In this function, num_choose_arg_maps is read from the message, and a corresponding number of crush_choose_arg_maps gets decoded afterwards. Each crush_choose_arg_map has a choose_args_index, which serves as the key when inserting it into the choose_args rbtree of the decoded crush_map. If a (potentially corrupted) message contains two crush_choose_arg_maps with the same index, the assertion in insert_choose_arg_map() triggers a kernel BUG when trying to insert the second crush_choose_arg_map. This patch fixes the issue by switching to the non-asserting rbtree insertion function and rejecting the message if the insertion fails. [ idryomov: changelog ] 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: Fix potential out-of-bounds access in crush_decode()

2026-06-01T15:39:33+00:00

commit 4c79fc2d598694bda845b46229c9d48b65042970 upstream. A message of type CEPH_MSG_OSD_MAP containing a crush map with at least one bucket has two fields holding the bucket algorithm. If the values in these two fields differ, an out-of-bounds access can occur. This is the case because the first algorithm field (alg) is used to allocate the correct amount of memory for a bucket of this type, while the second algorithm field inside the bucket (b->alg) is used in the subsequent processing. This patch fixes the issue by adding a check that compares alg and b->alg and aborts the processing in case they differ. Furthermore, b->alg is set to 0 in this case, because the destruction of the crush map also uses this field to determine the bucket type, which can again result in an out-of-bounds access when trying to free the memory pointed to by the fields of the bucket. To correctly free the memory allocated for the bucket in such a case, the corresponding call to kfree is moved from the algorithm-specific crush_destroy_bucket functions to the generic crush_destroy_bucket(). 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: Fix potential null-ptr-deref in decode_choose_args()

2026-06-01T15:39:32+00:00

commit 28b0a2ab8c82d0bbdeb8013029c67c978ce6e4bf upstream. A message of type CEPH_MSG_OSD_MAP contains an OSD map that itself contains a CRUSH map. When decoding this CRUSH map in crush_decode(), an array of max_buckets CRUSH buckets is decoded, where some indices may not refer to actual buckets and are therefore set to NULL. The received CRUSH map may optionally contain choose_args that get decoded in decode_choose_args(). When decoding a crush_choose_arg_map, a series of choose_args for different buckets is decoded, with the bucket_index being read from the incoming message. It is only checked that the bucket index does not exceed max_buckets, but not that it doesn't point to an index with a NULL bucket. If a (potentially corrupted) message contains a crush_choose_arg_map including such a bucket_index, a null pointer dereference may occur in the subsequent processing when attempting to access the bucket with the given index. This patch fixes the issue by extending the affected check. Now, it is only attempted to access the bucket if it is not NULL. 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: Fix potential out-of-bounds access in osdmap_decode()

2026-06-01T15:39:32+00:00

commit 35d0ed82d03e5ee77ea4f31f20e29562a7721649 upstream. When decoding osd_state and osd_weight from an incoming osdmap in osdmap_decode(), both are decoded for each osd, i.e., map->max_osd times. The ceph_decode_need() check only accounts for sizeof(*map->osd_weight) once. This can potentially result in an out-of-bounds memory access if the incoming message is corrupted such that the max_osd value exceeds the actual content of the osdmap message. This patch fixes the issue by changing the corresponding part in the ceph_decode_need() check to account for map->max_osd*sizeof(*map->osd_weight). Cc: stable@vger.kernel.org Fixes: dcbc919a5dc8 ("libceph: switch osdmap decoding to use ceph_decode_entity_addr") Signed-off-by: Raphael Zimmer Reviewed-by: Ilya Dryomov Signed-off-by: Ilya Dryomov Signed-off-by: Greg Kroah-Hartman