CVE-2026-28476

In the Linux kernel, a vulnerability in skb_zerocopy() was fixed: it incorrectly called skb_tx_error() on the source skb when copying frags. This completed the zerocopy uarg and cleared the SKBFL_SHARED_FRAG flag on an skb still in use by the network stack. Specifically on the OVS_ACTION_ATTR_USERSPACE path, the skb was not freed on error, which could lead to ESP data being decrypted in place where the skb did not privately own frags, potentially causing data corruption or other issues.

A vulnerability was found in the Linux kernel's Ceph filesystem where ceph_fname_to_usr() passed vmalloc() buffers to the fscrypt crypto API, which requires linear memory. This can cause kernel oopses, especially on non-x86 platforms. The fix adds support for vmalloc() buffers using a bounce buffer.

In the Linux kernel, nfsd4_revoke_export_states() drops nn->client_lock but the held stateid reference does not pin the client. A concurrent client teardown can free the client while revoke_one_stid() still dereferences it, causing a use-after-free.

In the Linux kernel, an nfs4_openowner left on nn->close_lru holds only a raw pointer to its nfs4_client. When the laundromat reaps entries, drops client_lock and calls nfs4_put_stid(), a concurrent force_expire_client() can free the client, causing a use-after-free.

In the Linux kernel, a bare lock owner left on nn->blocked_locks_lru holds only a raw pointer to its nfs4_client. When the laundromat reaps such a lock, the final nfs4_put_stateowner() takes the client's cl_lock, which a concurrent force_expire_client() may have already freed, causing a use-after-free.

In the Linux kernel, __spi_map_msg() mishandles DMA mapping ownership on partial map failure. When RX or TX mapping fails, flags and device pointers are not properly cleared, which can lead to re-unmapping or using a NULL/stale device pointer. This can trigger a kernel oops.

In the Linux kernel, the scsi target iscsi function iscsi_target_check_login_request() does not reserve a NUL terminator byte for the login buffer. With payload_length from 8189 to 8192, the entire 8192-byte buffer is filled and then consumed as a C string, leading to out-of-bounds reads. The vulnerability is reachable by an unauthenticated initiator when CHAP is configured.

In the Linux kernel, ceph_mds_check_access() traverses the s_cap_auths array without holding the mutex. A concurrent MDS session reopen can free this array while it is being inspected, resulting in a use-after-free.

In the Linux kernel, the nvme_alloc_ns() error path removes the namespace from the sibling list using list_del_rcu() but does not wait for SRCU readers before freeing the namespace struct. A concurrent reader in the multipath code may still hold a reference to ns when kfree(ns) runs, leading to a use-after-free.

In the Linux kernel, nvmet_auth_sq_free() cancels auth_expired_work with cancel_delayed_work(), which does not wait for an already-started callback. As a result, during transport teardown the queue containing struct nvmet_sq can be freed or reused while nvmet_auth_expired_work() still accesses it.