CVE-2026-98357 (GCVE-0-2026-98357)
Vulnerability from cvelistv5
Published
2026-10-06 08:46
Modified
2026-10-19 09:18
Summary
In the Linux kernel, the following vulnerability has been resolved: IB/isert: wait for deferred control PDU completions before releasing the connection isert_send_done() hands ISTATE_SEND_TASKMGTRSP, ISTATE_SEND_REJECT and ISTATE_SEND_TEXTRSP completions off to isert_comp_wq and returns. The work item then runs isert_completion_put() -> isert_put_cmd(), which reads isert_conn->conn and takes conn->cmd_lock. Nothing orders that work item against teardown. isert_wait_conn() queues isert_release_work, which frees isert_conn, and iscsit_close_connection() frees the iscsit_conn right after it returns, so the queued work can run against freed memory. Count the deferred control PDU completions per connection and let isert_wait_conn() wait for them before the release work is queued. ISTATE_SEND_LOGOUTRSP is deliberately not counted: that branch runs iscsit_logout_post_handler(), which ends up waiting for conn->conn_wait_comp, and that completion is only sent by iscsit_close_connection() after it has called iscsit_wait_conn(). Waiting for it here would deadlock. Its wait stays the existing isert_wait4logout(). The splat below is from a kernel with tracing printk()s and an msleep(200) injected into isert_do_control_comp() to widen the window: BUG: KASAN: slab-use-after-free in isert_put_cmd+0x53d/0x620 Read of size 8 at addr ffff8881054f1038 by task kworker/u17:1/182 CPU: 0 UID: 0 PID: 182 Comm: kworker/u17:1 Tainted: G B 7.2.0-rc5-TWIDE-gb8babf08acc7 #1 PREEMPT(lazy) Tainted: [B]=BAD_PAGE 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 Workqueue: isert_comp_wq isert_do_control_comp Call Trace: <TASK> dump_stack_lvl+0x53/0x70 print_report+0xd0/0x630 ? __pfx__raw_spin_lock_irqsave+0x10/0x10 ? _raw_spin_unlock_irqrestore+0x3e/0x70 ? isert_put_cmd+0x53d/0x620 kasan_report+0xce/0x100 ? isert_put_cmd+0x53d/0x620 isert_put_cmd+0x53d/0x620 ? isert_completion_put+0x305/0x330 ? isert_do_control_comp+0x2ef/0x310 process_one_work+0x633/0x1030 ? assign_work+0x11d/0x370 worker_thread+0x45b/0xd10 ? __pfx_worker_thread+0x10/0x10 ? __pfx_worker_thread+0x10/0x10 kthread+0x2c6/0x3b0 ? recalc_sigpending+0x15c/0x1e0 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x36e/0x5a0 ? __pfx_ret_from_fork+0x10/0x10 ? __switch_to+0x572/0xdd0 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> Allocated by task 48: kasan_save_stack+0x33/0x60 kasan_save_track+0x14/0x30 __kasan_kmalloc+0x8f/0xa0 __kmalloc_cache_noprof+0x158/0x370 isert_cma_handler+0x1e3/0x2ae0 cma_cm_event_handler+0x3e/0x240 cma_ib_req_handler+0x17d9/0x4490 cm_process_work+0x41/0x330 cm_work_handler+0x5727/0xc160 process_one_work+0x633/0x1030 worker_thread+0x45b/0xd10 kthread+0x2c6/0x3b0 ret_from_fork+0x36e/0x5a0 ret_from_fork_asm+0x1a/0x30 Freed by task 184: kasan_save_stack+0x33/0x60 kasan_save_track+0x14/0x30 kasan_save_free_info+0x3b/0x60 __kasan_slab_free+0x43/0x70 kfree+0x121/0x380 iscsit_close_connection+0x7cf/0x1e60 iscsit_take_action_for_connection_exit+0x1b6/0x360 iscsi_target_tx_thread+0x472/0x690 kthread+0x2c6/0x3b0 ret_from_fork+0x36e/0x5a0 ret_from_fork_asm+0x1a/0x30
Impacted products
Vendor Product Version
Linux Linux Version: b8d26b3be8b33682cf163274ed07479a70554633
Version: b8d26b3be8b33682cf163274ed07479a70554633
Version: b8d26b3be8b33682cf163274ed07479a70554633
Version: b8d26b3be8b33682cf163274ed07479a70554633
Version: b8d26b3be8b33682cf163274ed07479a70554633
Version: b8d26b3be8b33682cf163274ed07479a70554633
Version: b8d26b3be8b33682cf163274ed07479a70554633
Version: b8d26b3be8b33682cf163274ed07479a70554633
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{
  "containers": {
    "cna": {
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        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/infiniband/ulp/isert/ib_isert.c",
            "drivers/infiniband/ulp/isert/ib_isert.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "status": "affected",
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              "versionType": "git"
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              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/infiniband/ulp/isert/ib_isert.c",
            "drivers/infiniband/ulp/isert/ib_isert.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.10"
            },
            {
              "lessThan": "3.10",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.271",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.222",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.189",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.158",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.112",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.54",
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            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.8",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
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                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.10.271",
                  "versionStartIncluding": "3.10",
                  "vulnerable": true
                },
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                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.222",
                  "versionStartIncluding": "3.10",
                  "vulnerable": true
                },
                {
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                {
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                },
                {
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                  "versionEndExcluding": "7.2.8",
                  "versionStartIncluding": "3.10",
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                },
                {
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                  "versionEndExcluding": "7.3",
                  "versionStartIncluding": "3.10",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "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() -\u003e isert_put_cmd(), which reads\nisert_conn-\u003econn and takes conn-\u003ecmd_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-\u003econn_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   \u003cTASK\u003e\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   \u003c/TASK\u003e\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"
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 8.1,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "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\u0027t 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\u0027s 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-\u003econn 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(\u0026conn-\u003ecmd_lock), runs list_del_init(\u0026cmd-\u003ei_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."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-19T09:18:07.886Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/f5613acbe2e346d5c466ef0bd264fca936b69f82"
        },
        {
          "url": "https://git.kernel.org/stable/c/ccdb1523f12bc8a9646de65055d1aafed9e9bcc6"
        },
        {
          "url": "https://git.kernel.org/stable/c/0e230917670c6e6fe3243abfa11299fcbe05b1f4"
        },
        {
          "url": "https://git.kernel.org/stable/c/505b242d9351690d1385bbe508ab4666f60363ce"
        },
        {
          "url": "https://git.kernel.org/stable/c/7edb8a88d6c76237c8b4435765bee1009e26a50a"
        },
        {
          "url": "https://git.kernel.org/stable/c/b96b8b3e41c308f606ffd10cfef1a7b9f97414cd"
        },
        {
          "url": "https://git.kernel.org/stable/c/7908fbc597a694bbd99bfb59ece73bc3daded68e"
        },
        {
          "url": "https://git.kernel.org/stable/c/a8fe3dfce8c0d8a76dc3d8486a5bff5feebe156f"
        }
      ],
      "title": "IB/isert: wait for deferred control PDU completions before releasing the connection",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-98357",
    "datePublished": "2026-10-06T08:46:44.216Z",
    "dateReserved": "2026-09-25T10:25:14.344Z",
    "dateUpdated": "2026-10-19T09:18:07.886Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.


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