CVE-2026-52954

Description

In the Linux kernel, the following vulnerability has been resolved: libceph: handle rbtree insertion error in decode_choose_args() 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 ]

References

• https://git.kernel.org/stable/c/0a1265a9ab875f92b6a3ffb497404f46cf9d76a3
• https://git.kernel.org/stable/c/0b6a3bcb91bc5bfeda39f0df3b71bab62c13e9da
• https://git.kernel.org/stable/c/4d2b37abda9536808655830d683dc491d31741a8
• https://git.kernel.org/stable/c/534ebc08df97c47d4c7596f336fa31ecbf91519c
• https://git.kernel.org/stable/c/80c73bd1b2b04355d1d0c29be8ccbd25a380905d