{ "schema_version": "1.6.1", "id": "RPI-CVE-2026-98357", "modified": "2026-10-09T11:39:44Z", "upstream": [ "CVE-2026-98357" ], "published": "2026-10-06T08:47:10Z", "summary": "IB/isert: wait for deferred control PDU completions before releasing the connection", "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nIB/isert: wait for deferred control PDU completions before releasing the connection\n\nisert_send_done() hands ISTATE_SEND_TASKMGTRSP, ISTATE_SEND_REJECT and\nISTATE_SEND_TEXTRSP completions off to isert_comp_wq and returns. The work\nitem then runs isert_completion_put() -> isert_put_cmd(), which reads\nisert_conn->conn and takes conn->cmd_lock.\n\nNothing orders that work item against teardown. isert_wait_conn() queues\nisert_release_work, which frees isert_conn, and iscsit_close_connection()\nfrees the iscsit_conn right after it returns, so the queued work can run\nagainst freed memory.\n\nCount the deferred control PDU completions per connection and let\nisert_wait_conn() wait for them before the release work is queued.\n\nISTATE_SEND_LOGOUTRSP is deliberately not counted: that branch runs\niscsit_logout_post_handler(), which ends up waiting for\nconn->conn_wait_comp, and that completion is only sent by\niscsit_close_connection() after it has called iscsit_wait_conn().\nWaiting for it here would deadlock. Its wait stays the existing\nisert_wait4logout().\n\nThe splat below is from a kernel with tracing printk()s and an msleep(200)\ninjected into isert_do_control_comp() to widen the window:\n\n BUG: KASAN: slab-use-after-free in isert_put_cmd+0x53d/0x620\n Read of size 8 at addr ffff8881054f1038 by task kworker/u17:1/182\n\n CPU: 0 UID: 0 PID: 182 Comm: kworker/u17:1 Tainted: G B 7.2.0-rc5-TWIDE-gb8babf08acc7 #1 PREEMPT(lazy)\n Tainted: [B]=BAD_PAGE\n Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014\n Workqueue: isert_comp_wq isert_do_control_comp\n Call Trace:\n \n dump_stack_lvl+0x53/0x70\n print_report+0xd0/0x630\n ? __pfx__raw_spin_lock_irqsave+0x10/0x10\n ? _raw_spin_unlock_irqrestore+0x3e/0x70\n ? isert_put_cmd+0x53d/0x620\n kasan_report+0xce/0x100\n ? isert_put_cmd+0x53d/0x620\n isert_put_cmd+0x53d/0x620\n ? isert_completion_put+0x305/0x330\n ? isert_do_control_comp+0x2ef/0x310\n process_one_work+0x633/0x1030\n ? assign_work+0x11d/0x370\n worker_thread+0x45b/0xd10\n ? __pfx_worker_thread+0x10/0x10\n ? __pfx_worker_thread+0x10/0x10\n kthread+0x2c6/0x3b0\n ? recalc_sigpending+0x15c/0x1e0\n ? __pfx_kthread+0x10/0x10\n ret_from_fork+0x36e/0x5a0\n ? __pfx_ret_from_fork+0x10/0x10\n ? __switch_to+0x572/0xdd0\n ? __pfx_kthread+0x10/0x10\n ret_from_fork_asm+0x1a/0x30\n \n\n Allocated by task 48:\n kasan_save_stack+0x33/0x60\n kasan_save_track+0x14/0x30\n __kasan_kmalloc+0x8f/0xa0\n __kmalloc_cache_noprof+0x158/0x370\n isert_cma_handler+0x1e3/0x2ae0\n cma_cm_event_handler+0x3e/0x240\n cma_ib_req_handler+0x17d9/0x4490\n cm_process_work+0x41/0x330\n cm_work_handler+0x5727/0xc160\n process_one_work+0x633/0x1030\n worker_thread+0x45b/0xd10\n kthread+0x2c6/0x3b0\n ret_from_fork+0x36e/0x5a0\n ret_from_fork_asm+0x1a/0x30\n\n Freed by task 184:\n kasan_save_stack+0x33/0x60\n kasan_save_track+0x14/0x30\n kasan_save_free_info+0x3b/0x60\n __kasan_slab_free+0x43/0x70\n kfree+0x121/0x380\n iscsit_close_connection+0x7cf/0x1e60\n iscsit_take_action_for_connection_exit+0x1b6/0x360\n iscsi_target_tx_thread+0x472/0x690\n kthread+0x2c6/0x3b0\n ret_from_fork+0x36e/0x5a0\n ret_from_fork_asm+0x1a/0x30", "severity": [ { "type": "CVSS_V3", "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H" } ], "affected": [ { "package": { "ecosystem": "Raspberry Pi OS:12", "name": "linux" }, "versions": [ "1:6.1.47-1+rpt4" ], "ecosystem_specific": { "binaries": [ { "binary_name": "linux-image-6.1.0-rpi3-rpi-2712", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v6", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v7", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v8", "binary_version": "1:6.1.47-1+rpt4" } ] }, "database_specific": { "per_version": { "1:6.1.47-1+rpt4": { "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e", "upstream_version": "6.1.47", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.1.189", "compiled_filter": false } } } } ], "references": [ { "type": "ADVISORY", "url": "https://www.cve.org/CVERecord?id=CVE-2026-98357" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/f5613acbe2e346d5c466ef0bd264fca936b69f82" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/ccdb1523f12bc8a9646de65055d1aafed9e9bcc6" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/0e230917670c6e6fe3243abfa11299fcbe05b1f4" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/505b242d9351690d1385bbe508ab4666f60363ce" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/7edb8a88d6c76237c8b4435765bee1009e26a50a" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/b96b8b3e41c308f606ffd10cfef1a7b9f97414cd" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/7908fbc597a694bbd99bfb59ece73bc3daded68e" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/a8fe3dfce8c0d8a76dc3d8486a5bff5feebe156f" } ], "database_specific": { "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git", "upstream_modified": "2026-10-07T06:50:27Z", "severity": { "source": "kernel CNA", "cvss_v3_score": 8.1, "cvss_v3_severity": "High", "scenario": "AV:N - The iSER initiator triggers it remotely over RDMA (iWARP/RoCEv2 are IP-routable). Its iSCSI Text Request (or a TMF or a malformed PDU that draws a Reject) makes isert_send_done() queue isert_do_control_comp(); an RDMA CM disconnect from the same initiator then starts teardown via iscsit_close_connection().\nAC:H - The attacker sends both the request and the disconnect, but the free only wins if the already-queued isert_comp_wq work stays delayed through ib_drain_qp, isert_wait4cmds and the release work. The attacker can't control that scheduling; the reporter needed an injected msleep(200) to reproduce it.\nPR:N - The attacker only needs a full-feature iSCSI session, and LIO allows login with AuthMethod=None, where the initiator IQN is merely asserted. No credentials are checked before the Text/TMF/Reject paths that queue the deferred completion.\nUI:N - The initiator triggers the response PDU and the connection teardown entirely through its own iSCSI PDUs and RDMA CM disconnect; no action by a target administrator is needed.\nS:U - The use-after-free is in the target host's own kernel memory (isert_conn and iscsit_conn), so the impact stays within the same kernel security authority.\nC:H - isert_put_cmd() dereferences the freed isert_conn->conn and reads the freed iscsit_conn and cmd structures. Reclaiming those slab objects lets attacker-shaped data steer kernel pointer reads.\nI:H - On the freed iscsit_conn, isert_put_cmd() takes spin_lock_bh(&conn->cmd_lock), runs list_del_init(&cmd->i_conn_node) and calls iscsit_release_cmd()/transport_generic_free_cmd(). These are writes and frees through freed memory, which can corrupt the heap.\nA:H - The isert_comp_wq worker hits a slab use-after-free in isert_put_cmd() (KASAN splat in the fix commit), which on production kernels can crash or oops the iSCSI target host." } } }