This is a note to let you know that I've just added the patch titled RDMA/srpt: Fix a use-after-free to the 5.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: rdma-srpt-fix-a-use-after-free.patch and it can be found in the queue-5.18 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 9c74a33362e69384092368dbda0548e80f036a32 Author: Bart Van Assche <bvanassche@xxxxxxx> Date: Wed Jul 27 12:34:15 2022 -0700 RDMA/srpt: Fix a use-after-free [ Upstream commit b5605148e6ce36bb21020d49010b617693933128 ] Change the LIO port members inside struct srpt_port from regular members into pointers. Allocate the LIO port data structures from inside srpt_make_tport() and free these from inside srpt_make_tport(). Keep struct srpt_device as long as either an RDMA port or a LIO target port is associated with it. This patch decouples the lifetime of struct srpt_port (controlled by the RDMA core) and struct srpt_port_id (controlled by LIO). This patch fixes the following KASAN complaint: BUG: KASAN: use-after-free in srpt_enable_tpg+0x31/0x70 [ib_srpt] Read of size 8 at addr ffff888141cc34b8 by task check/5093 Call Trace: <TASK> show_stack+0x4e/0x53 dump_stack_lvl+0x51/0x66 print_address_description.constprop.0.cold+0xea/0x41e print_report.cold+0x90/0x205 kasan_report+0xb9/0xf0 __asan_load8+0x69/0x90 srpt_enable_tpg+0x31/0x70 [ib_srpt] target_fabric_tpg_base_enable_store+0xe2/0x140 [target_core_mod] configfs_write_iter+0x18b/0x210 new_sync_write+0x1f2/0x2f0 vfs_write+0x3e3/0x540 ksys_write+0xbb/0x140 __x64_sys_write+0x42/0x50 do_syscall_64+0x34/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 </TASK> Link: https://lore.kernel.org/r/20220727193415.1583860-4-bvanassche@xxxxxxx Reported-by: Li Zhijian <lizhijian@xxxxxxxxxxx> Tested-by: Li Zhijian <lizhijian@xxxxxxxxxxx> Fixes: a42d985bd5b2 ("ib_srpt: Initial SRP Target merge for v3.3-rc1") Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx> Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.c b/drivers/infiniband/ulp/srpt/ib_srpt.c index 1fbce9225424..c3036aeac89e 100644 --- a/drivers/infiniband/ulp/srpt/ib_srpt.c +++ b/drivers/infiniband/ulp/srpt/ib_srpt.c @@ -565,18 +565,12 @@ static int srpt_refresh_port(struct srpt_port *sport) if (ret) return ret; - sport->port_guid_id.wwn.priv = sport; srpt_format_guid(sport->guid_name, ARRAY_SIZE(sport->guid_name), &sport->gid.global.interface_id); - memcpy(sport->port_guid_id.name, sport->guid_name, - ARRAY_SIZE(sport->guid_name)); - sport->port_gid_id.wwn.priv = sport; snprintf(sport->gid_name, ARRAY_SIZE(sport->gid_name), "0x%016llx%016llx", be64_to_cpu(sport->gid.global.subnet_prefix), be64_to_cpu(sport->gid.global.interface_id)); - memcpy(sport->port_gid_id.name, sport->gid_name, - ARRAY_SIZE(sport->gid_name)); if (rdma_protocol_iwarp(sport->sdev->device, sport->port)) return 0; @@ -2317,31 +2311,35 @@ static int srpt_cm_req_recv(struct srpt_device *const sdev, tag_num = ch->rq_size; tag_size = 1; /* ib_srpt does not use se_sess->sess_cmd_map */ - mutex_lock(&sport->port_guid_id.mutex); - list_for_each_entry(stpg, &sport->port_guid_id.tpg_list, entry) { - if (!IS_ERR_OR_NULL(ch->sess)) - break; - ch->sess = target_setup_session(&stpg->tpg, tag_num, + if (sport->guid_id) { + mutex_lock(&sport->guid_id->mutex); + list_for_each_entry(stpg, &sport->guid_id->tpg_list, entry) { + if (!IS_ERR_OR_NULL(ch->sess)) + break; + ch->sess = target_setup_session(&stpg->tpg, tag_num, tag_size, TARGET_PROT_NORMAL, ch->sess_name, ch, NULL); + } + mutex_unlock(&sport->guid_id->mutex); } - mutex_unlock(&sport->port_guid_id.mutex); - mutex_lock(&sport->port_gid_id.mutex); - list_for_each_entry(stpg, &sport->port_gid_id.tpg_list, entry) { - if (!IS_ERR_OR_NULL(ch->sess)) - break; - ch->sess = target_setup_session(&stpg->tpg, tag_num, + if (sport->gid_id) { + mutex_lock(&sport->gid_id->mutex); + list_for_each_entry(stpg, &sport->gid_id->tpg_list, entry) { + if (!IS_ERR_OR_NULL(ch->sess)) + break; + ch->sess = target_setup_session(&stpg->tpg, tag_num, tag_size, TARGET_PROT_NORMAL, i_port_id, ch, NULL); - if (!IS_ERR_OR_NULL(ch->sess)) - break; - /* Retry without leading "0x" */ - ch->sess = target_setup_session(&stpg->tpg, tag_num, + if (!IS_ERR_OR_NULL(ch->sess)) + break; + /* Retry without leading "0x" */ + ch->sess = target_setup_session(&stpg->tpg, tag_num, tag_size, TARGET_PROT_NORMAL, i_port_id + 2, ch, NULL); + } + mutex_unlock(&sport->gid_id->mutex); } - mutex_unlock(&sport->port_gid_id.mutex); if (IS_ERR_OR_NULL(ch->sess)) { WARN_ON_ONCE(ch->sess == NULL); @@ -2986,7 +2984,12 @@ static int srpt_release_sport(struct srpt_port *sport) return 0; } -static struct se_wwn *__srpt_lookup_wwn(const char *name) +struct port_and_port_id { + struct srpt_port *sport; + struct srpt_port_id **port_id; +}; + +static struct port_and_port_id __srpt_lookup_port(const char *name) { struct ib_device *dev; struct srpt_device *sdev; @@ -3001,25 +3004,38 @@ static struct se_wwn *__srpt_lookup_wwn(const char *name) for (i = 0; i < dev->phys_port_cnt; i++) { sport = &sdev->port[i]; - if (strcmp(sport->port_guid_id.name, name) == 0) - return &sport->port_guid_id.wwn; - if (strcmp(sport->port_gid_id.name, name) == 0) - return &sport->port_gid_id.wwn; + if (strcmp(sport->guid_name, name) == 0) { + kref_get(&sdev->refcnt); + return (struct port_and_port_id){ + sport, &sport->guid_id}; + } + if (strcmp(sport->gid_name, name) == 0) { + kref_get(&sdev->refcnt); + return (struct port_and_port_id){ + sport, &sport->gid_id}; + } } } - return NULL; + return (struct port_and_port_id){}; } -static struct se_wwn *srpt_lookup_wwn(const char *name) +/** + * srpt_lookup_port() - Look up an RDMA port by name + * @name: ASCII port name + * + * Increments the RDMA port reference count if an RDMA port pointer is returned. + * The caller must drop that reference count by calling srpt_port_put_ref(). + */ +static struct port_and_port_id srpt_lookup_port(const char *name) { - struct se_wwn *wwn; + struct port_and_port_id papi; spin_lock(&srpt_dev_lock); - wwn = __srpt_lookup_wwn(name); + papi = __srpt_lookup_port(name); spin_unlock(&srpt_dev_lock); - return wwn; + return papi; } static void srpt_free_srq(struct srpt_device *sdev) @@ -3198,10 +3214,6 @@ static int srpt_add_one(struct ib_device *device) sport->port_attrib.srp_sq_size = DEF_SRPT_SQ_SIZE; sport->port_attrib.use_srq = false; INIT_WORK(&sport->work, srpt_refresh_port_work); - mutex_init(&sport->port_guid_id.mutex); - INIT_LIST_HEAD(&sport->port_guid_id.tpg_list); - mutex_init(&sport->port_gid_id.mutex); - INIT_LIST_HEAD(&sport->port_gid_id.tpg_list); ret = srpt_refresh_port(sport); if (ret) { @@ -3302,10 +3314,10 @@ static struct srpt_port_id *srpt_wwn_to_sport_id(struct se_wwn *wwn) { struct srpt_port *sport = wwn->priv; - if (wwn == &sport->port_guid_id.wwn) - return &sport->port_guid_id; - if (wwn == &sport->port_gid_id.wwn) - return &sport->port_gid_id; + if (sport->guid_id && &sport->guid_id->wwn == wwn) + return sport->guid_id; + if (sport->gid_id && &sport->gid_id->wwn == wwn) + return sport->gid_id; WARN_ON_ONCE(true); return NULL; } @@ -3790,7 +3802,31 @@ static struct se_wwn *srpt_make_tport(struct target_fabric_configfs *tf, struct config_group *group, const char *name) { - return srpt_lookup_wwn(name) ? : ERR_PTR(-EINVAL); + struct port_and_port_id papi = srpt_lookup_port(name); + struct srpt_port *sport = papi.sport; + struct srpt_port_id *port_id; + + if (!papi.port_id) + return ERR_PTR(-EINVAL); + if (*papi.port_id) { + /* Attempt to create a directory that already exists. */ + WARN_ON_ONCE(true); + return &(*papi.port_id)->wwn; + } + port_id = kzalloc(sizeof(*port_id), GFP_KERNEL); + if (!port_id) { + srpt_sdev_put(sport->sdev); + return ERR_PTR(-ENOMEM); + } + mutex_init(&port_id->mutex); + INIT_LIST_HEAD(&port_id->tpg_list); + port_id->wwn.priv = sport; + memcpy(port_id->name, port_id == sport->guid_id ? sport->guid_name : + sport->gid_name, ARRAY_SIZE(port_id->name)); + + *papi.port_id = port_id; + + return &port_id->wwn; } /** @@ -3799,6 +3835,18 @@ static struct se_wwn *srpt_make_tport(struct target_fabric_configfs *tf, */ static void srpt_drop_tport(struct se_wwn *wwn) { + struct srpt_port_id *port_id = container_of(wwn, typeof(*port_id), wwn); + struct srpt_port *sport = wwn->priv; + + if (sport->guid_id == port_id) + sport->guid_id = NULL; + else if (sport->gid_id == port_id) + sport->gid_id = NULL; + else + WARN_ON_ONCE(true); + + srpt_sdev_put(sport->sdev); + kfree(port_id); } static ssize_t srpt_wwn_version_show(struct config_item *item, char *buf) diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.h b/drivers/infiniband/ulp/srpt/ib_srpt.h index 0cb867d580f1..4c46b301eea1 100644 --- a/drivers/infiniband/ulp/srpt/ib_srpt.h +++ b/drivers/infiniband/ulp/srpt/ib_srpt.h @@ -393,7 +393,7 @@ struct srpt_port_id { }; /** - * struct srpt_port - information associated by SRPT with a single IB port + * struct srpt_port - SRPT RDMA port information * @sdev: backpointer to the HCA information. * @mad_agent: per-port management datagram processing information. * @enabled: Whether or not this target port is enabled. @@ -403,9 +403,9 @@ struct srpt_port_id { * @gid: cached value of the port's gid. * @work: work structure for refreshing the aforementioned cached values. * @guid_name: port name in GUID format. - * @port_guid_id: LIO target port information for the port name in GUID format. + * @guid_id: LIO target port information for the port name in GUID format. * @gid_name: port name in GID format. - * @port_gid_id: LIO target port information for the port name in GID format. + * @gid_id: LIO target port information for the port name in GID format. * @port_attrib: Port attributes that can be accessed through configfs. * @refcount: Number of objects associated with this port. * @freed_channels: Completion that will be signaled once @refcount becomes 0. @@ -422,9 +422,9 @@ struct srpt_port { union ib_gid gid; struct work_struct work; char guid_name[64]; - struct srpt_port_id port_guid_id; + struct srpt_port_id *guid_id; char gid_name[64]; - struct srpt_port_id port_gid_id; + struct srpt_port_id *gid_id; struct srpt_port_attrib port_attrib; atomic_t refcount; struct completion *freed_channels;