linux.git/net/ceph/osdmap.c, branch master

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

2026-07-23T18:29:42Z

__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

libceph: guard missing CRUSH type name lookup

2026-07-23T18:29:41Z

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

libceph: reject zero bucket types in crush_decode

2026-07-23T18:29:40Z

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

libceph: Fix multiplication overflow in decode_new_up_state_weight()

2026-07-23T18:29:40Z

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

libceph: Fix potential null-ptr-deref in decode_choose_args()

2026-05-12T19:00:59Z

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

libceph: handle rbtree insertion error in decode_choose_args()

2026-05-12T19:00:58Z

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

libceph: Fix potential out-of-bounds access in osdmap_decode()

2026-05-11T18:53:53Z

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

libceph: Fix unnecessarily high ceph_decode_need() for uniform bucket

2026-05-11T08:39:22Z

In crush_decode_uniform_bucket(), the item_weight field of the bucket is set. This is a single field of type u32 since the uniform bucket uses the same weight for all items. The value in ceph_decode_need() is set to (1+b->h.size) * sizeof(u32), which is higher than actually needed. This patch removes the call to ceph_decode_need() with the unnecessarily high value and switches the subsequent operation from ceph_decode_32() to ceph_decode_32_safe(), which already includes the correct bounds check. Signed-off-by: Raphael Zimmer Reviewed-by: Ilya Dryomov Signed-off-by: Ilya Dryomov

libceph: Fix potential out-of-bounds access in crush_decode()

2026-05-11T08:39:21Z

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

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28Z

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook