{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-98357","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-09-25T10:25:14.344Z","datePublished":"2026-10-06T08:46:44.216Z","dateUpdated":"2026-10-07T06:50:12.677Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-10-07T06:50:12.677Z"},"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() -> 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   <TASK>\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   </TASK>\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":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":8.1,"baseSeverity":"HIGH"},"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'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."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/infiniband/ulp/isert/ib_isert.c","drivers/infiniband/ulp/isert/ib_isert.h"],"versions":[{"version":"b8d26b3be8b33682cf163274ed07479a70554633","lessThan":"f5613acbe2e346d5c466ef0bd264fca936b69f82","status":"affected","versionType":"git"},{"version":"b8d26b3be8b33682cf163274ed07479a70554633","lessThan":"ccdb1523f12bc8a9646de65055d1aafed9e9bcc6","status":"affected","versionType":"git"},{"version":"b8d26b3be8b33682cf163274ed07479a70554633","lessThan":"0e230917670c6e6fe3243abfa11299fcbe05b1f4","status":"affected","versionType":"git"},{"version":"b8d26b3be8b33682cf163274ed07479a70554633","lessThan":"505b242d9351690d1385bbe508ab4666f60363ce","status":"affected","versionType":"git"},{"version":"b8d26b3be8b33682cf163274ed07479a70554633","lessThan":"7edb8a88d6c76237c8b4435765bee1009e26a50a","status":"affected","versionType":"git"},{"version":"b8d26b3be8b33682cf163274ed07479a70554633","lessThan":"b96b8b3e41c308f606ffd10cfef1a7b9f97414cd","status":"affected","versionType":"git"},{"version":"b8d26b3be8b33682cf163274ed07479a70554633","lessThan":"7908fbc597a694bbd99bfb59ece73bc3daded68e","status":"affected","versionType":"git"},{"version":"b8d26b3be8b33682cf163274ed07479a70554633","lessThan":"a8fe3dfce8c0d8a76dc3d8486a5bff5feebe156f","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/infiniband/ulp/isert/ib_isert.c","drivers/infiniband/ulp/isert/ib_isert.h"],"versions":[{"version":"3.10","status":"affected"},{"version":"0","lessThan":"3.10","status":"unaffected","versionType":"semver"},{"version":"5.10.271","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.222","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.189","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.158","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.112","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.54","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.8","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3-rc4","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.10","versionEndExcluding":"5.10.271"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.10","versionEndExcluding":"5.15.222"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.10","versionEndExcluding":"6.1.189"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.10","versionEndExcluding":"6.6.158"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.10","versionEndExcluding":"6.12.112"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.10","versionEndExcluding":"6.18.54"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.10","versionEndExcluding":"7.2.8"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.10","versionEndExcluding":"7.3-rc4"}]}]}],"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"}}}}