kernel/linux.git/net/ceph/osdmap.c, branch v7.1-rc5

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

2026-05-12T19:00:59+00:00

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()

2026-05-12T19:00:58+00:00

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()

2026-05-11T18:53:53+00:00

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

2026-05-11T08:39:22+00:00

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()

2026-05-11T08:39:21+00:00

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

2026-02-21T09:02:28+00:00

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

libceph: make free_choose_arg_map() resilient to partial allocation

2026-01-05T12:28:26+00:00

free_choose_arg_map() may dereference a NULL pointer if its caller fails after a partial allocation. For example, in decode_choose_args(), if allocation of arg_map->args fails, execution jumps to the fail label and free_choose_arg_map() is called. Since arg_map->size is updated to a non-zero value before memory allocation, free_choose_arg_map() will iterate over arg_map->args and dereference a NULL pointer. To prevent this potential NULL pointer dereference and make free_choose_arg_map() more resilient, add checks for pointers before iterating. Cc: stable@vger.kernel.org Co-authored-by: Ilya Dryomov Signed-off-by: Tuo Li Reviewed-by: Viacheslav Dubeyko Signed-off-by: Ilya Dryomov

libceph: replace overzealous BUG_ON in osdmap_apply_incremental()

2026-01-05T12:28:26+00:00

If the osdmap is (maliciously) corrupted such that the incremental osdmap epoch is different from what is expected, there is no need to BUG. Instead, just declare the incremental osdmap to be invalid. Cc: stable@vger.kernel.org Reported-by: ziming zhang Signed-off-by: Ilya Dryomov

libceph: make decode_pool() more resilient against corrupted osdmaps

2025-12-10T10:50:54+00:00

If the osdmap is (maliciously) corrupted such that the encoded length of ceph_pg_pool envelope is less than what is expected for a particular encoding version, out-of-bounds reads may ensue because the only bounds check that is there is based on that length value. This patch adds explicit bounds checks for each field that is decoded or skipped. Cc: stable@vger.kernel.org Reported-by: ziming zhang Signed-off-by: Ilya Dryomov Reviewed-by: Xiubo Li Tested-by: ziming zhang

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

2025-12-10T10:50:54+00:00

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