{"id":"CVE-2026-99152","kind":"vulnerability","aliases":["CVE-2026-99152"],"related":[],"title":"Linux kernel iSCSI: unsolicited target response crashes the host with a null dereference","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nscsi: libiscsi: Validate the task named by a management response\n\n__iscsi_complete_pdu() fetches the task for five response types from one\nplace and checks only that the index resolved:\n\n      case ISCSI_OP_LOGOUT_RSP:\n      case ISCSI_OP_LOGIN_RSP:\n      case ISCSI_OP_TEXT_RSP:\n      case ISCSI_OP_SCSI_TMFUNC_RSP:\n      case ISCSI_OP_NOOP_IN:\n              task = iscsi_itt_to_task(conn, hdr->itt);\n              if (!task)\n                      return ISCSI_ERR_BAD_ITT;\n\niscsi_itt_to_task() bounds the index against cmds_max and looks at\nnothing else, so a target can name any slot in the pool, including one\nthat has never been used. task->conn is then NULL, and both\niscsi_nop_out_rsp() and iscsi_complete_task() dereference it. One\nunsolicited NOP-In is enough; a Text Response carrying the same ITT\ncrashes in iscsi_complete_task() instead.\n\nRequire the task to be in flight and not a SCSI command, the way\niscsi_itt_to_ctask() does for the command opcodes.\n\n[    6.298634] Oops: general protection fault, probably for non-canonical address 0xdffffc000000000c: 0000 [#1] SMP KASAN NOPTI\n[    6.298642] KASAN: null-ptr-deref in range [0x0000000000000060-0x0000000000000067]\n[    6.298652] CPU: 1 UID: 0 PID: 111 Comm: iscsistart Not tainted 7.2.0-rc5-ISCSI1-gf5098b6bae76 #1 PREEMPT(lazy)\n[    6.298654] 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[    6.298656] RIP: 0010:iscsi_nop_out_rsp.constprop.0+0x46/0x160\n[    6.298691] Code: c1 ea 03 48 83 ec 08 80 3c 02 00 0f 85 f5 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 6b 58 48 8d 7d 60 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 c0 00 00 00 48 8b 45 60 48 39 c3 74 50 48 b8 00\n[    6.298698] RSP: 0018:ffff88806c907be8 EFLAGS: 00010206\n[    6.298701] RAX: dffffc0000000000 RBX: ffff888006116800 RCX: 0000000000000020\n[    6.298702] RDX: 000000000000000c RSI: ffff88800525d578 RDI: 0000000000000060\n[    6.298703] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000\n[    6.298706] R10: 0000000000000020 R11: 0000000000000000 R12: 0000000000000000\n[    6.298706] R13: 000000000000002e R14: ffff8880056eb440 R15: ffff888006116800\n[    6.298707] FS:  00007fc02d1c2740(0000) GS:ffff8880b29bc000(0000) knlGS:0000000000000000\n[    6.298710] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n[    6.298711] CR2: 000055fe3b56ddf8 CR3: 00000000053b9004 CR4: 0000000000770ef0\n[    6.298712] PKRU: 55555554\n[    6.298713] Call Trace:\n[    6.298714]  <IRQ>\n[    6.298714]  __iscsi_complete_pdu+0x13a8/0x22a0\n[    6.298758]  iscsi_complete_pdu+0x54/0xa0\n[    6.298759]  iscsi_tcp_hdr_recv_done+0x870/0x2c80\n[    6.298778]  iscsi_tcp_recv_skb+0x31e/0xec0\n[    6.298800]  iscsi_sw_tcp_recv+0x12f/0x390\n[    6.298804]  __tcp_read_sock+0x1ab/0x810\n[    6.298812]  iscsi_sw_tcp_data_ready+0x18b/0x510\n[    6.298814]  tcp_rcv_established+0x1f56/0x3a00\n[    6.298842]  tcp_v4_do_rcv+0x449/0x960\n[    6.298847]  tcp_v4_rcv+0x2245/0x3bc0","summary":"The Linux kernel's libiscsi accepts a management response that names an unused task slot, then dereferences a null connection pointer. A malicious or compromised iSCSI target can send one unsolicited NOP-In or Text Response and crash the initiator kernel.","severity":"high","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["infrastructure","iscsi","kernel","linux","storage"],"not_affected_if":["kernel-without-libiscsi","no-iscsi-sessions"],"how_to_check":"- Run `uname -r` and compare against the fixed kernel builds listed by your distribution\n- Check whether the iSCSI initiator is loaded with `lsmod | grep -E 'libiscsi|iscsi_tcp'`\n- Confirm the host uses iSCSI sessions to targets with `iscsiadm -m session`","fix":"- Update the Linux kernel to a release that includes the libiscsi fix (the upstream commit 'scsi: libiscsi: Validate the task named by a management response'); the sources do not name a fixed version\n- Reboot after the kernel update so the patched module is running","status":"open","published_at":"2026-10-28T11:17:35+00:00","first_seen_at":"2026-10-28T11:32:35+00:00","triaged_at":"2026-10-28T11:35:55+00:00","updated_at":"2026-10-28T11:35:55+00:00","category":"infrastructure","confidence":0.6,"triage":{"at":"2026-10-28T11:35:55Z","model":"claude-haiku-5-5","output":{"fix":"- Update the Linux kernel to a release that includes the libiscsi fix (the upstream commit 'scsi: libiscsi: Validate the task named by a management response'); the sources do not name a fixed version\n- Reboot after the kernel update so the patched module is running","reach":"network","title":"Linux kernel iSCSI: unsolicited target response crashes the host with a null dereference","impact":"low","summary":"The Linux kernel's libiscsi accepts a management response that names an unused task slot, then dereferences a null connection pointer. A malicious or compromised iSCSI target can send one unsolicited NOP-In or Text Response and crash the initiator kernel.","category":"infrastructure","nicknames":[],"who_cares":["linux","iscsi","kernel","storage"],"confidence":0.6,"needs_auth":"unknown","worst_case":"Initiator kernel crashes from a single crafted iSCSI response packet","analyst_note":"Sources give no fixed kernel version or affected version range; check the upstream kernel commit and distro advisories for the fixed release.","how_to_check":"- Run `uname -r` and compare against the fixed kernel builds listed by your distribution\n- Check whether the iSCSI initiator is loaded with `lsmod | grep -E 'libiscsi|iscsi_tcp'`\n- Confirm the host uses iSCSI sessions to targets with `iscsiadm -m session`","needs_analyst":true,"not_affected_if":["no-iscsi-sessions","kernel-without-libiscsi"],"who_is_affected":"Hosts running the Linux kernel's iSCSI initiator (libiscsi with iscsi_tcp or iscsi_sw_tcp) that log in to iSCSI targets. The attacker has to be the target or sit on the session, so exposure depends on who controls the storage endpoints. Hosts without iSCSI sessions can skip it.","user_interaction":"no","needs_special_setup":"yes","severity_if_unknown":"high"},"cost_usd":0.000832,"input_tokens":4878,"output_tokens":688,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'+0':312C,457C,463C,471C,478C,485C,491C,499C,505C,512C,518C '-2':305C '-2026':15A,18A '-99152':16A,19A '0':272C,311C '00':326C,330C,331C,332C,335C,336C,337C,338C,339C,361C,365C,366C,367C,379C '0000':252C,424C,427C,434C,436C '0000000000000000':402C,404C,406C,411C,413C,429C '000000000000000c':395C '0000000000000020':392C,409C '000000000000002e':416C '0000000000000060':399C '0000000000770ef0':445C '00000000053b9004':443C '0000000080050033':438C '000055fe3b56ddf8':441C '00007fc02d1c2740':423C '00010206':385C '0010':309C,432C '0018':382C '02':325C,360C '03':318C,357C '04/01/2014':306C '08':322C '0f':327C,362C '0x0000000000000060':266C '0x0000000000000060-0x0000000000000067':265C '0x0000000000000067':267C '0xdffffc000000000c':251C '1':253C,270C,284C '1.16.3':302C,304C '111':274C '1996':300C '24.04':292C '39':373C '3c':324C,359C '45':370C '48':319C,333C,343C,347C,351C,354C,368C,372C,377C '50':376C '55555554':448C '58':346C '6.298634':240C '6.298642':257C '6.298652':268C '6.298654':287C '6.298656':307C '6.298691':314C '6.298698':380C '6.298701':386C '6.298702':393C '6.298703':400C '6.298706':407C,414C '6.298707':421C '6.298710':430C '6.298711':439C '6.298712':446C '6.298713':449C '6.298714':452C,453C '6.298758':459C '6.298759':465C '6.298778':473C '6.298800':480C '6.298804':487C '6.298812':493C '6.298814':501C '6.298842':507C '6.298847':514C '60':350C,371C '6b':345C '7.2.0':279C '74':375C '7d':349C '80':323C,358C '83':320C '85':328C,363C '89':352C '8b':344C,369C '8d':348C 'accept':30B 'address':250C 'arch':297C 'b8':334C,378C 'bad':146C 'bio':301C 'bound':152C 'c0':364C 'c1':316C,355C 'c3':374C 'call':450C 'canon':249C 'cap':298C 'carri':207C 'case':107C,112C,117C,122C,128C 'check':101C 'cmds':156C 'code':315C 'comm':275C 'command':228C,238C 'complet':88C,193C,214C,455C,461C 'compromis':49B 'conn':138C,181C 'connect':44B 'cpu':269C 'cr0':437C 'cr2':440C 'cr3':442C 'cr4':444C 'crash':7A,63B,211C 'cs':431C 'ctask':234C 'cve':14A,17A 'data':497C 'debian':303C 'deref':262C 'derefer':13A,41B,195C 'df':342C 'dffffc0000000000':388C 'done':470C 'ds':433C 'ea':317C,356C 'ec':321C 'eflag':384C 'els':162C 'enough':203C 'err':145C 'es':435C 'establish':504C 'f5':329C 'fa':353C 'fault':244C 'fc':340C 'fetch':90C 'ff':341C 'ffff88800525d578':397C 'ffff8880056eb440':418C 'ffff888006116800':390C,420C 'ffff88806c907be8':383C 'ffff8880b29bc000':426C 'five':94C 'fix':299C 'flight':223C 'follow':72C 'fs':422C 'general':242C 'gf5098b6bae76':283C 'gs':425C 'hardwar':288C 'hdr':139C,468C 'host':9A 'i440fx':295C 'includ':173C 'index':105C,154C 'infrastructur':20B 'initi':65B 'instead':216C 'iscsi':3A,21B,50B,87C,108C,113C,118C,123C,129C,134C,144C,148C,187C,192C,213C,231C,454C,460C,466C,474C,481C,494C 'iscsi1':282C 'iscsi_nop_out_rsp.constprop':310C 'iscsistart':276C 'itt':135C,140C,147C,149C,210C,232C 'kasan':255C,258C 'kernel':2A,22B,27B,66B,70C 'knlgs':428C 'lazi':286C 'libiscsi':29B,78C 'linux':1A,23B,26B,69C 'login':115C 'logout':110C 'look':159C 'malici':47B 'manag':32B,85C 'max':157C 'name':35B,82C,167C,289C 'never':177C 'non':248C 'non-canon':247C 'noop':131C 'nop':57B,188C,200C 'nop-in':56B,199C 'nopti':256C 'noth':161C 'null':12A,43B,184C,260C 'null-ptr-deref':259C 'one':54B,98C,174C,197C 'oop':241C 'op':109C,114C,119C,124C,130C 'opcod':239C 'pc':293C 'pdu':89C,456C,462C 'pid':273C 'piix':296C 'pkru':447C 'place':99C 'pointer':45B 'pool':172C 'preempt':285C 'probabl':245C 'protect':243C 'ptr':261C 'qemu':290C 'r08':403C 'r09':405C 'r10':408C 'r11':410C 'r12':412C 'r13':415C 'r14':417C 'r15':419C 'rang':264C 'rax':387C 'rbp':401C 'rbx':389C 'rc5':281C 'rc5-iscsi1-gf5098b6bae76':280C 'rcv':503C,511C,517C 'rcx':391C 'rdi':398C 'rdx':394C 'read':489C 'readi':498C 'recv':469C,476C,484C 'requir':217C 'resolv':76C,106C 'respons':6A,33B,61B,86C,95C,206C 'return':143C 'rip':308C 'rsi':396C 'rsp':111C,116C,121C,127C,190C,381C 'scsi':77C,125C,227C 'send':53B 'skb':477C 'slot':39B,169C 'smp':254C 'sock':490C 'storag':24B 'sw':482C,495C 'taint':278C 'target':5A,51B,165C 'task':38B,81C,92C,133C,137C,142C,151C,180C,194C,215C,219C 'tcp':467C,475C,483C,488C,496C,502C,508C,515C 'text':60B,120C,205C 'tmfunc':126C 'trace':451C 'type':96C 'ubuntu':291C 'uid':271C 'unsolicit':4A,55B,198C 'unus':37B 'use':179C 'v2':294C 'v4':509C,516C 'valid':79C 'vulner':73C 'way':230C 'x12f/0x390':486C 'x13a8/0x22a0':458C 'x18b/0x510':500C 'x1ab/0x810':492C 'x1f56/0x3a00':506C 'x2245/0x3bc0':519C 'x31e/0xec0':479C 'x449/0x960':513C 'x46/0x160':313C 'x54/0xa0':464C 'x870/0x2c80':472C","nicknames":[],"mitigations":[],"who_affected":"Hosts running the Linux kernel's iSCSI initiator (libiscsi with iscsi_tcp or iscsi_sw_tcp) that log in to iSCSI targets. The attacker has to be the target or sit on the session, so exposure depends on who controls the storage endpoints. Hosts without iSCSI sessions can skip it.","tier":"B","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-28T11:17:35+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-99152","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-99152","severity":null,"published_at":"2026-10-28T11:17:35+00:00","modified_at":"2026-10-28T11:17:35+00:00","first_seen_at":"2026-10-28T11:32:35+00:00","fetched_at":"2026-10-28T11:32:35+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}