{"id":"CVE-2026-98357","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() -\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","modified":"2026-10-07T02:47:30.515126422Z","published":"2026-10-06T08:46:44.216Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98357.json","cna_assigner":"Linux"},"references":[{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"},{"type":"WEB","url":"https://git.kernel.org/stable/c/0e230917670c6e6fe3243abfa11299fcbe05b1f4"},{"type":"WEB","url":"https://git.kernel.org/stable/c/505b242d9351690d1385bbe508ab4666f60363ce"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7908fbc597a694bbd99bfb59ece73bc3daded68e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7edb8a88d6c76237c8b4435765bee1009e26a50a"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a8fe3dfce8c0d8a76dc3d8486a5bff5feebe156f"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b96b8b3e41c308f606ffd10cfef1a7b9f97414cd"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ccdb1523f12bc8a9646de65055d1aafed9e9bcc6"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f5613acbe2e346d5c466ef0bd264fca936b69f82"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98357.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98357"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"b8d26b3be8b33682cf163274ed07479a70554633"},{"fixed":"f5613acbe2e346d5c466ef0bd264fca936b69f82"},{"fixed":"ccdb1523f12bc8a9646de65055d1aafed9e9bcc6"},{"fixed":"0e230917670c6e6fe3243abfa11299fcbe05b1f4"},{"fixed":"505b242d9351690d1385bbe508ab4666f60363ce"},{"fixed":"7edb8a88d6c76237c8b4435765bee1009e26a50a"},{"fixed":"b96b8b3e41c308f606ffd10cfef1a7b9f97414cd"},{"fixed":"7908fbc597a694bbd99bfb59ece73bc3daded68e"},{"fixed":"a8fe3dfce8c0d8a76dc3d8486a5bff5feebe156f"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98357.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.10.0"},{"fixed":"5.10.271"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.222"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.189"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.158"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.112"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.54"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.8"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98357.json"}}],"schema_version":"1.9.0"}