kernel/linux.git/drivers/dibs, branch v6.18.48

dibs: initialise dibs->lock in dibs_dev_alloc()

2026-08-19T16:18:18+00:00

commit c27e360545373b7aee9862a5beef3b9fb3df0c25 upstream. dibs->lock is initialised by dibs_dev_add(), but a dibs device can already take interrupts before that call: ism_probe() runs ism_dev_init(), and hence request_irq(), before it calls dibs_dev_add(). No client can have registered a dmb at that point, so no dmb interrupt can occur, but a GID event interrupt can, and ism_handle_irq() takes dibs->lock unconditionally on entry, before it inspects anything else. Initialise the lock in dibs_dev_alloc() instead, so that it is valid as soon as a driver can publish the device to its interrupt handler. Fixes: cc21191b584c ("dibs: Move data path to dibs layer") Cc: stable@vger.kernel.org Reviewed-by: Alexandra Winter Signed-off-by: Hidayath Khan Link: https://patch.msgid.link/20260730124227.167829-1-hidayath@linux.ibm.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

net/dibs: Correct freeing of dmb_clientid_arr

2026-08-19T16:18:17+00:00

commit 9e6869be49064915edb6c8776b27c376cfdb0df5 upstream. A dibs device interrupt handler can be active after dibs_dev_del() and may still access dmb_clientid_arr. (UAF) In case of a failure in dibs_dev_add() being called by dibs_lo_dev_probe() dmb_clientid_arr is freed twice (double free). Free dmb_clientid_arr in dibs_dev_release() after last reference is gone. Note that allocating in dibs_dev_add() instead of dibs_dev_alloc() is ok for now, because no dmbs can be registered before dibs_dev_add(). Fixes: cc21191b584c ("dibs: Move data path to dibs layer") Cc: stable@vger.kernel.org Co-developed-by: Hidayath Khan Signed-off-by: Hidayath Khan Signed-off-by: Alexandra Winter Reviewed-by: Dust Li Link: https://patch.msgid.link/20260810111432.2334900-1-wintera@linux.ibm.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

dibs: fix use-after-free of dmb_node in loopback attach/detach/unregister

2026-08-09T18:25:12+00:00

commit a10ea943356b9d70c5616a0a06f6fa97cfdaccb1 upstream. dibs_lo_attach_dmb(), dibs_lo_detach_dmb() and dibs_lo_unregister_dmb() look up the dmb_node under dmb_ht_lock, drop the lock and only then operate on the node's refcount. Nothing keeps the node alive across that window: __dibs_lo_unregister_dmb() removes the node from the hash table under the write lock and immediately frees it. A concurrent final put can therefore free the node between the lookup and the refcount operation: CPU0 (attach) CPU1 (owner unregisters) read_lock_bh(&dmb_ht_lock) find dmb_node (refcnt == 1) read_unlock_bh(&dmb_ht_lock) refcount_dec_and_test() 1 -> 0 write_lock_bh(&dmb_ht_lock) hash_del(&dmb_node->list) write_unlock_bh(&dmb_ht_lock) kfree(dmb_node) refcount_inc_not_zero(&dmb_node->refcnt) <-- use-after-free The same window exists for the refcount_dec_and_test() calls in the detach and unregister paths. Close the race structurally by making hash table membership and the refcount transitions atomic with respect to each other: - Perform the final refcount_dec_and_test() and hash_del() in a single dmb_ht_lock write-side critical section, in both the unregister and the detach path. Freeing the node still happens after the lock is dropped, which is safe because a node whose refcount reached zero has left the hash table and can no longer be found. - This establishes the invariant that any node found in the hash table holds at least one reference, and that the final reference can only be dropped under the write lock. dibs_lo_attach_dmb() can thus take its reference with a plain refcount_inc() while still holding the read lock; refcount_inc_not_zero() is no longer needed. __dibs_lo_unregister_dmb() no longer touches the hash table and is renamed to dibs_lo_free_dmb() accordingly. Note: commit cc21191b584c ("dibs: Move data path to dibs layer") moved the code to its current location; the race was introduced earlier by commit c3a910f2380f ("net/smc: implement DMB-merged operations of loopback-ism"). Tested SMC-D via ISM and dibs loopback. Cc: stable@vger.kernel.org Fixes: c3a910f2380f ("net/smc: implement DMB-merged operations of loopback-ism") Reported-by: Rahul Chandelkar Signed-off-by: Hidayath Khan Reviewed-by: Alexandra Winter Link: https://patch.msgid.link/20260727093530.968834-1-hidayath@linux.ibm.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

dibs: loopback: validate offset and size in move_data()

2026-07-24T14:17:16+00:00

commit 78237e3c0720fcc6eb9b87e90fd70f63eeca886f upstream. The loopback move_data() performs a memcpy into the registered DMB without checking whether offset + size exceeds the DMB length. Unlike real ISM hardware, which enforces memory region bounds natively, the software loopback has no such protection. A peer-supplied out-of-bounds offset or oversized write would result in an OOB write past the allocated kernel buffer. Add an explicit bounds check before the memcpy to reject such requests with -EINVAL. Fixes: f7a22071dbf3 ("net/smc: implement DMB-related operations of loopback-ism") Cc: stable@vger.kernel.org Reported-by: Federico Kirschbaum Signed-off-by: Dust Li Reported-by: Baul Lee Link: https://patch.msgid.link/20260707074318.1448662-1-dust.li@linux.alibaba.com Signed-off-by: Paolo Abeni Signed-off-by: Greg Kroah-Hartman

dibs: Check correct variable in dibs_init()

2025-09-26T22:10:59+00:00

There is a typo in this code. It should check "dibs_class" instead of "&dibs_class". Remove the &. Fixes: 804737349813 ("dibs: Create class dibs") Signed-off-by: Dan Carpenter Reviewed-by: Alexandra Winter Link: https://patch.msgid.link/aNP-XcrjSUjZAu4a@stanley.mountain Signed-off-by: Jakub Kicinski

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2025-09-25T18:00:59+00:00

Cross-merge networking fixes after downstream PR (net-6.17-rc8). Conflicts: drivers/net/can/spi/hi311x.c 6b6968084721 ("can: hi311x: fix null pointer dereference when resuming from sleep before interface was enabled") 27ce71e1ce81 ("net: WQ_PERCPU added to alloc_workqueue users") https://lore.kernel.org/72ce7599-1b5b-464a-a5de-228ff9724701@kernel.org net/smc/smc_loopback.c drivers/dibs/dibs_loopback.c a35c04de2565 ("net/smc: fix warning in smc_rx_splice() when calling get_page()") cc21191b584c ("dibs: Move data path to dibs layer") https://lore.kernel.org/74368a5c-48ac-4f8e-a198-40ec1ed3cf5f@kernel.org Adjacent changes: drivers/net/dsa/lantiq/lantiq_gswip.c c0054b25e2f1 ("net: dsa: lantiq_gswip: move gswip_add_single_port_br() call to port_setup()") 7a1eaef0a791 ("net: dsa: lantiq_gswip: support model-specific mac_select_pcs()") Signed-off-by: Jakub Kicinski

dibs: Move event handling to dibs layer

2025-09-23T09:13:22+00:00

Add defines for all event types and subtypes an ism device is known to produce as it can be helpful for debugging purposes. Introduces a generic 'struct dibs_event' and adopt ism device driver and smc-d client accordingly. Tolerate and ignore other type and subtype values to enable future device extensions. SMC-D and ISM are now independent. struct ism_dev can be moved to drivers/s390/net/ism.h. Note that in smc, the term 'ism' is still used. Future patches could replace that with 'dibs' or 'smc-d' as appropriate. Signed-off-by: Julian Ruess Co-developed-by: Alexandra Winter Signed-off-by: Alexandra Winter Link: https://patch.msgid.link/20250918110500.1731261-15-wintera@linux.ibm.com Signed-off-by: Paolo Abeni

dibs: Move data path to dibs layer

2025-09-23T09:13:22+00:00

Use struct dibs_dmb instead of struct smc_dmb and move the corresponding client tables to dibs_dev. Leave driver specific implementation details like sba in the device drivers. Register and unregister dmbs via dibs_dev_ops. A dmb is dedicated to a single client, but a dibs device can have dmbs for more than one client. Trigger dibs clients via dibs_client_ops->handle_irq(), when data is received into a dmb. For dibs_loopback replace scheduling an smcd receive tasklet with calling dibs_client_ops->handle_irq(). For loopback devices attach_dmb(), detach_dmb() and move_data() need to access the dmb tables, so move those to dibs_dev_ops in this patch as well. Remove remaining definitions of smc_loopback as they are no longer required, now that everything is in dibs_loopback. Note that struct ism_client and struct ism_dev are still required in smc until a follow-on patch moves event handling to dibs. (Loopback does not use events). Signed-off-by: Alexandra Winter Link: https://patch.msgid.link/20250918110500.1731261-14-wintera@linux.ibm.com Signed-off-by: Paolo Abeni

dibs: Move query_remote_gid() to dibs_dev_ops

2025-09-23T09:13:22+00:00

Provide the dibs_dev_ops->query_remote_gid() in ism and dibs_loopback dibs_devices. And call it in smc dibs_client. Reviewed-by: Julian Ruess Signed-off-by: Alexandra Winter Link: https://patch.msgid.link/20250918110500.1731261-13-wintera@linux.ibm.com Signed-off-by: Paolo Abeni

dibs: Local gid for dibs devices

2025-09-23T09:13:22+00:00

Define a uuid_t GID attribute to identify a dibs device. SMC uses 64 Bit and 128 Bit Global Identifiers (GIDs) per device, that need to be sent via the SMC protocol. Because the smc code uses integers, network endianness and host endianness need to be considered. Avoid this in the dibs layer by using uuid_t byte arrays. Future patches could change SMC to use uuid_t. For now conversion helper functions are introduced. ISM devices provide 64 Bit GIDs. Map them to dibs uuid_t GIDs like this: _________________________________________ | 64 Bit ISM-vPCI GID | 00000000_00000000 | ----------------------------------------- If interpreted as UUID [1], this would be interpreted as the UIID variant, that is reserved for NCS backward compatibility. So it will not collide with UUIDs that were generated according to the standard. smc_loopback already uses version 4 UUIDs as 128 Bit GIDs, move that to dibs loopback. A temporary change to smc_lo_query_rgid() is required, that will be moved to dibs_loopback with a follow-on patch. Provide gid of a dibs device as sysfs read-only attribute. Link: https://datatracker.ietf.org/doc/html/rfc4122 [1] Signed-off-by: Alexandra Winter Reviewed-by: Julian Ruess Reviewed-by: Mahanta Jambigi Link: https://patch.msgid.link/20250918110500.1731261-11-wintera@linux.ibm.com Signed-off-by: Paolo Abeni