CVE-2024-35870

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2024-35870", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-05-17T13:50:33.108Z", "datePublished": "2024-05-19T08:34:28.419Z", "dateUpdated": "2026-08-05T11:30:32.619Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:30:32.619Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix UAF in smb2_reconnect_server()\n\nThe UAF bug is due to smb2_reconnect_server() accessing a session that\nis already being teared down by another thread that is executing\n__cifs_put_smb_ses(). This can happen when (a) the client has\nconnection to the server but no session or (b) another thread ends up\nsetting @ses->ses_status again to something different than\nSES_EXITING.\n\nTo fix this, we need to make sure to unconditionally set\n@ses->ses_status to SES_EXITING and prevent any other threads from\nsetting a new status while we're still tearing it down.\n\nThe following can be reproduced by adding some delay to right after\nthe ipc is freed in __cifs_put_smb_ses() - which will give\nsmb2_reconnect_server() worker a chance to run and then accessing\n@ses->ipc:\n\nkinit ...\nmount.cifs //srv/share /mnt/1 -o sec=krb5,nohandlecache,echo_interval=10\n[disconnect srv]\nls /mnt/1 &>/dev/null\nsleep 30\nkdestroy\n[reconnect srv]\nsleep 10\numount /mnt/1\n...\nCIFS: VFS: Verify user has a krb5 ticket and keyutils is installed\nCIFS: VFS: \\\\srv Send error in SessSetup = -126\nCIFS: VFS: Verify user has a krb5 ticket and keyutils is installed\nCIFS: VFS: \\\\srv Send error in SessSetup = -126\ngeneral protection fault, probably for non-canonical address\n0x6b6b6b6b6b6b6b6b: 0000 [#1] PREEMPT SMP NOPTI\nCPU: 3 PID: 50 Comm: kworker/3:1 Not tainted 6.9.0-rc2 #1\nHardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-1.fc39\n04/01/2014\nWorkqueue: cifsiod smb2_reconnect_server [cifs]\nRIP: 0010:__list_del_entry_valid_or_report+0x33/0xf0\nCode: 4f 08 48 85 d2 74 42 48 85 c9 74 59 48 b8 00 01 00 00 00 00 ad\nde 48 39 c2 74 61 48 b8 22 01 00 00 00 00 74 69 <48> 8b 01 48 39 f8 75\n7b 48 8b 72 08 48 39 c6 0f 85 88 00 00 00 b8\nRSP: 0018:ffffc900001bfd70 EFLAGS: 00010a83\nRAX: dead000000000122 RBX: ffff88810da53838 RCX: 6b6b6b6b6b6b6b6b\nRDX: 6b6b6b6b6b6b6b6b RSI: ffffffffc02f6878 RDI: ffff88810da53800\nRBP: ffff88810da53800 R08: 0000000000000001 R09: 0000000000000000\nR10: 0000000000000000 R11: 0000000000000001 R12: ffff88810c064000\nR13: 0000000000000001 R14: ffff88810c064000 R15: ffff8881039cc000\nFS: 0000000000000000(0000) GS:ffff888157c00000(0000)\nknlGS:0000000000000000\nCS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 00007fe3728b1000 CR3: 000000010caa4000 CR4: 0000000000750ef0\nPKRU: 55555554\nCall Trace:\n <TASK>\n ? die_addr+0x36/0x90\n ? exc_general_protection+0x1c1/0x3f0\n ? asm_exc_general_protection+0x26/0x30\n ? __list_del_entry_valid_or_report+0x33/0xf0\n __cifs_put_smb_ses+0x1ae/0x500 [cifs]\n smb2_reconnect_server+0x4ed/0x710 [cifs]\n process_one_work+0x205/0x6b0\n worker_thread+0x191/0x360\n ? __pfx_worker_thread+0x10/0x10\n kthread+0xe2/0x110\n ? __pfx_kthread+0x10/0x10\n ret_from_fork+0x34/0x50\n ? __pfx_kthread+0x10/0x10\n ret_from_fork_asm+0x1a/0x30\n </TASK>"}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL"}, "scenarios": [{"lang": "en", "value": "AV:N - The race is driven entirely by remote SMB server behavior \u2014 TCP disconnects, malformed/short responses, decryption failures, or withheld replies all reach `cifs_reconnect()` \u2192 `cifs_mark_tcp_ses_conns_for_reconnect()` from the demultiplex thread, and the freed tcon's contents are transmitted back over the network. A malicious/compromised SMB server or an on-path attacker against an existing CIFS mount exploits this remotely.\nAC:L - The attacker controls both sides: it triggers reconnect at will (RST/close/malformed frame) and observes the SMB2 LOGOFF request that `__cifs_put_smb_ses()` sends before blocking, giving an explicit on-wire marker for the teardown window, and the reconnect worker self-requeues every 2 s so the race can be retried indefinitely. In scenario (a) \u2014 server accepts TCP but fails SESSION_SETUP \u2014 `SES_EXITING` is never set at all, so no timing win is even required.\nPR:N - The attacker is the remote peer and needs no privileges or account on the victim client; valid SMB credentials are not required, since failed session setup is precisely what drives the vulnerable state.\nUI:N - The attack targets an already-established CIFS mount (fstab/autofs/Kubernetes-mounted shares on servers, NAS-backed embedded and industrial systems); reconnect and session teardown are triggered by the attacker and by background workers with no user action at attack time.\nS:U - Corruption is confined to kernel heap objects within the same security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - The freed IPC `cifs_tcon` is re-read and `tcon->tree_name` is sent to the attacker-controlled server in the TREE_CONNECT, leaking reclaimed kernel heap contents directly to the attacker, and the freed `cifs_ses` holds session keys and `auth_key.response`; the UAF read primitive is unbounded.\nI:H - `cifs_smb_ses_inc_refcount()` writes to freed memory and `list_del_init(&ses->smb_ses_list)` performs a `prev->next = next` write through pointers read from a freed, sprayable kmalloc object \u2014 a write-what-where primitive suitable for control-flow hijack.\nA:H - The bug reproducibly causes a general protection fault in the cifsiod kworker (`__list_del_entry_valid_or_report` on 0x6b6b6b6b poison), killing the worker and panicking the system on `panic_on_oops` configurations."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/smb/client/connect.c"], "versions": [{"version": "b327a717e506980399464e304e363f94f95eb7a1", "lessThan": "755fe68cd4b59e1d2a2dd3286177fd4404f57fed", "status": "affected", "versionType": "git"}, {"version": "b327a717e506980399464e304e363f94f95eb7a1", "lessThan": "6202996a1c1887e83d0b3b0fcd86d0e5e6910ea0", "status": "affected", "versionType": "git"}, {"version": "b327a717e506980399464e304e363f94f95eb7a1", "lessThan": "45f2beda1f1bc3d962ec07db1ccc3197c25499a5", "status": "affected", "versionType": "git"}, {"version": "b327a717e506980399464e304e363f94f95eb7a1", "lessThan": "24a9799aa8efecd0eb55a75e35f9d8e6400063aa", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/smb/client/connect.c"], "versions": [{"version": "4.16", "status": "affected"}, {"version": "0", "lessThan": "4.16", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.121", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.29", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.8.5", "lessThanOrEqual": "6.8.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.9", "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": "4.16", "versionEndExcluding": "6.1.121"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.16", "versionEndExcluding": "6.6.29"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.16", "versionEndExcluding": "6.8.5"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.16", "versionEndExcluding": "6.9"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/755fe68cd4b59e1d2a2dd3286177fd4404f57fed"}, {"url": "https://git.kernel.org/stable/c/6202996a1c1887e83d0b3b0fcd86d0e5e6910ea0"}, {"url": "https://git.kernel.org/stable/c/45f2beda1f1bc3d962ec07db1ccc3197c25499a5"}, {"url": "https://git.kernel.org/stable/c/24a9799aa8efecd0eb55a75e35f9d8e6400063aa"}], "title": "smb: client: fix UAF in smb2_reconnect_server()", "x_generator": {"engine": "bippy-1.2.0"}}, "adp": [{"problemTypes": [{"descriptions": [{"type": "CWE", "cweId": "CWE-416", "lang": "en", "description": "CWE-416 Use After Free"}]}], "metrics": [{"cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 4.4, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "HIGH", "confidentialityImpact": "HIGH"}}, {"other": {"type": "ssvc", "content": {"timestamp": "2024-06-17T17:38:54.896093Z", "id": "CVE-2024-35870", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-10-27T14:02:11.836Z"}}, {"title": "CVE Program Container", "references": [{"url": "https://git.kernel.org/stable/c/6202996a1c1887e83d0b3b0fcd86d0e5e6910ea0", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/45f2beda1f1bc3d962ec07db1ccc3197c25499a5", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/24a9799aa8efecd0eb55a75e35f9d8e6400063aa", "tags": ["x_transferred"]}, {"url": "https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html"}], "providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T20:37:37.141Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CVE Program Container", "references": [{"url": "https://git.kernel.org/stable/c/6202996a1c1887e83d0b3b0fcd86d0e5e6910ea0", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/45f2beda1f1bc3d962ec07db1ccc3197c25499a5", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/24a9799aa8efecd0eb55a75e35f9d8e6400063aa", "tags": ["x_transferred"]}, {"url": "https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html"}], "providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T20:37:37.141Z"}}, {"title": "CISA ADP Vulnrichment", "metrics": [{"cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 4.4, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "HIGH", "confidentialityImpact": "HIGH"}}, {"other": {"type": "ssvc", "content": {"id": "CVE-2024-35870", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2024-06-17T17:38:54.896093Z"}}}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-416", "description": "CWE-416 Use After Free"}]}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-06-17T17:38:56.142Z"}}], "cna": {"title": "smb: client: fix UAF in smb2_reconnect_server()", "metrics": [{"cvssV3_1": {"version": "3.1", "baseScore": 9.8, "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}, "scenarios": [{"lang": "en", "value": "AV:N - The race is driven entirely by remote SMB server behavior \u2014 TCP disconnects, malformed/short responses, decryption failures, or withheld replies all reach `cifs_reconnect()` \u2192 `cifs_mark_tcp_ses_conns_for_reconnect()` from the demultiplex thread, and the freed tcon's contents are transmitted back over the network. A malicious/compromised SMB server or an on-path attacker against an existing CIFS mount exploits this remotely.\nAC:L - The attacker controls both sides: it triggers reconnect at will (RST/close/malformed frame) and observes the SMB2 LOGOFF request that `__cifs_put_smb_ses()` sends before blocking, giving an explicit on-wire marker for the teardown window, and the reconnect worker self-requeues every 2 s so the race can be retried indefinitely. In scenario (a) \u2014 server accepts TCP but fails SESSION_SETUP \u2014 `SES_EXITING` is never set at all, so no timing win is even required.\nPR:N - The attacker is the remote peer and needs no privileges or account on the victim client; valid SMB credentials are not required, since failed session setup is precisely what drives the vulnerable state.\nUI:N - The attack targets an already-established CIFS mount (fstab/autofs/Kubernetes-mounted shares on servers, NAS-backed embedded and industrial systems); reconnect and session teardown are triggered by the attacker and by background workers with no user action at attack time.\nS:U - Corruption is confined to kernel heap objects within the same security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - The freed IPC `cifs_tcon` is re-read and `tcon->tree_name` is sent to the attacker-controlled server in the TREE_CONNECT, leaking reclaimed kernel heap contents directly to the attacker, and the freed `cifs_ses` holds session keys and `auth_key.response`; the UAF read primitive is unbounded.\nI:H - `cifs_smb_ses_inc_refcount()` writes to freed memory and `list_del_init(&ses->smb_ses_list)` performs a `prev->next = next` write through pointers read from a freed, sprayable kmalloc object \u2014 a write-what-where primitive suitable for control-flow hijack.\nA:H - The bug reproducibly causes a general protection fault in the cifsiod kworker (`__list_del_entry_valid_or_report` on 0x6b6b6b6b poison), killing the worker and panicking the system on `panic_on_oops` configurations."}]}], "affected": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "b327a717e506980399464e304e363f94f95eb7a1", "lessThan": "755fe68cd4b59e1d2a2dd3286177fd4404f57fed", "versionType": "git"}, {"status": "affected", "version": "b327a717e506980399464e304e363f94f95eb7a1", "lessThan": "6202996a1c1887e83d0b3b0fcd86d0e5e6910ea0", "versionType": "git"}, {"status": "affected", "version": "b327a717e506980399464e304e363f94f95eb7a1", "lessThan": "45f2beda1f1bc3d962ec07db1ccc3197c25499a5", "versionType": "git"}, {"status": "affected", "version": "b327a717e506980399464e304e363f94f95eb7a1", "lessThan": "24a9799aa8efecd0eb55a75e35f9d8e6400063aa", "versionType": "git"}], "programFiles": ["fs/smb/client/connect.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "4.16"}, {"status": "unaffected", "version": "0", "lessThan": "4.16", "versionType": "semver"}, {"status": "unaffected", "version": "6.1.121", "versionType": "semver", "lessThanOrEqual": "6.1.*"}, {"status": "unaffected", "version": "6.6.29", "versionType": "semver", "lessThanOrEqual": "6.6.*"}, {"status": "unaffected", "version": "6.8.5", "versionType": "semver", "lessThanOrEqual": "6.8.*"}, {"status": "unaffected", "version": "6.9", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["fs/smb/client/connect.c"], "defaultStatus": "affected"}], "references": [{"url": "https://git.kernel.org/stable/c/755fe68cd4b59e1d2a2dd3286177fd4404f57fed"}, {"url": "https://git.kernel.org/stable/c/6202996a1c1887e83d0b3b0fcd86d0e5e6910ea0"}, {"url": "https://git.kernel.org/stable/c/45f2beda1f1bc3d962ec07db1ccc3197c25499a5"}, {"url": "https://git.kernel.org/stable/c/24a9799aa8efecd0eb55a75e35f9d8e6400063aa"}], "x_generator": {"engine": "bippy-1.2.0"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix UAF in smb2_reconnect_server()\n\nThe UAF bug is due to smb2_reconnect_server() accessing a session that\nis already being teared down by another thread that is executing\n__cifs_put_smb_ses(). This can happen when (a) the client has\nconnection to the server but no session or (b) another thread ends up\nsetting @ses->ses_status again to something different than\nSES_EXITING.\n\nTo fix this, we need to make sure to unconditionally set\n@ses->ses_status to SES_EXITING and prevent any other threads from\nsetting a new status while we're still tearing it down.\n\nThe following can be reproduced by adding some delay to right after\nthe ipc is freed in __cifs_put_smb_ses() - which will give\nsmb2_reconnect_server() worker a chance to run and then accessing\n@ses->ipc:\n\nkinit ...\nmount.cifs //srv/share /mnt/1 -o sec=krb5,nohandlecache,echo_interval=10\n[disconnect srv]\nls /mnt/1 &>/dev/null\nsleep 30\nkdestroy\n[reconnect srv]\nsleep 10\numount /mnt/1\n...\nCIFS: VFS: Verify user has a krb5 ticket and keyutils is installed\nCIFS: VFS: \\\\srv Send error in SessSetup = -126\nCIFS: VFS: Verify user has a krb5 ticket and keyutils is installed\nCIFS: VFS: \\\\srv Send error in SessSetup = -126\ngeneral protection fault, probably for non-canonical address\n0x6b6b6b6b6b6b6b6b: 0000 [#1] PREEMPT SMP NOPTI\nCPU: 3 PID: 50 Comm: kworker/3:1 Not tainted 6.9.0-rc2 #1\nHardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-1.fc39\n04/01/2014\nWorkqueue: cifsiod smb2_reconnect_server [cifs]\nRIP: 0010:__list_del_entry_valid_or_report+0x33/0xf0\nCode: 4f 08 48 85 d2 74 42 48 85 c9 74 59 48 b8 00 01 00 00 00 00 ad\nde 48 39 c2 74 61 48 b8 22 01 00 00 00 00 74 69 <48> 8b 01 48 39 f8 75\n7b 48 8b 72 08 48 39 c6 0f 85 88 00 00 00 b8\nRSP: 0018:ffffc900001bfd70 EFLAGS: 00010a83\nRAX: dead000000000122 RBX: ffff88810da53838 RCX: 6b6b6b6b6b6b6b6b\nRDX: 6b6b6b6b6b6b6b6b RSI: ffffffffc02f6878 RDI: ffff88810da53800\nRBP: ffff88810da53800 R08: 0000000000000001 R09: 0000000000000000\nR10: 0000000000000000 R11: 0000000000000001 R12: ffff88810c064000\nR13: 0000000000000001 R14: ffff88810c064000 R15: ffff8881039cc000\nFS: 0000000000000000(0000) GS:ffff888157c00000(0000)\nknlGS:0000000000000000\nCS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 00007fe3728b1000 CR3: 000000010caa4000 CR4: 0000000000750ef0\nPKRU: 55555554\nCall Trace:\n <TASK>\n ? die_addr+0x36/0x90\n ? exc_general_protection+0x1c1/0x3f0\n ? asm_exc_general_protection+0x26/0x30\n ? __list_del_entry_valid_or_report+0x33/0xf0\n __cifs_put_smb_ses+0x1ae/0x500 [cifs]\n smb2_reconnect_server+0x4ed/0x710 [cifs]\n process_one_work+0x205/0x6b0\n worker_thread+0x191/0x360\n ? __pfx_worker_thread+0x10/0x10\n kthread+0xe2/0x110\n ? __pfx_kthread+0x10/0x10\n ret_from_fork+0x34/0x50\n ? __pfx_kthread+0x10/0x10\n ret_from_fork_asm+0x1a/0x30\n </TASK>"}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.1.121", "versionStartIncluding": "4.16"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.6.29", "versionStartIncluding": "4.16"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.8.5", "versionStartIncluding": "4.16"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.9", "versionStartIncluding": "4.16"}], "operator": "OR"}]}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:30:32.619Z"}}}, "cveMetadata": {"cveId": "CVE-2024-35870", "state": "PUBLISHED", "dateUpdated": "2026-08-05T11:30:32.619Z", "dateReserved": "2024-05-17T13:50:33.108Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2024-05-19T08:34:28.419Z", "assignerShortName": "Linux"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["fs/smb/client/connect.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "755fe68cd4b59e1d2a2dd3286177fd4404f57fed", "status": "affected", "version": "b327a717e506980399464e304e363f94f95eb7a1", "versionType": "git"}, {"lessThan": "6202996a1c1887e83d0b3b0fcd86d0e5e6910ea0", "status": "affected", "version": "b327a717e506980399464e304e363f94f95eb7a1", "versionType": "git"}, {"lessThan": "45f2beda1f1bc3d962ec07db1ccc3197c25499a5", "status": "affected", "version": "b327a717e506980399464e304e363f94f95eb7a1", "versionType": "git"}, {"lessThan": "24a9799aa8efecd0eb55a75e35f9d8e6400063aa", "status": "affected", "version": "b327a717e506980399464e304e363f94f95eb7a1", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["fs/smb/client/connect.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "4.16"}, {"lessThan": "4.16", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.121", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.29", "versionType": "semver"}, {"lessThanOrEqual": "6.8.*", "status": "unaffected", "version": "6.8.5", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "6.9", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "391AABB6-B177-482C-9E7A-44C36BA7F003", "versionEndExcluding": "6.1.121", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "0999E154-1E68-41FA-8DE3-9A735E382224", "versionEndExcluding": "6.6.29", "versionStartIncluding": "6.2", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "DBD6C99E-4250-4DFE-8447-FF2075939D10", "versionEndExcluding": "6.8.5", "versionStartIncluding": "6.7", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.9:rc1:*:*:*:*:*:*", "matchCriteriaId": "22BEDD49-2C6D-402D-9DBF-6646F6ECD10B", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.9:rc2:*:*:*:*:*:*", "matchCriteriaId": "DF73CB2A-DFFD-46FB-9BFE-AA394F27EA37", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix UAF in smb2_reconnect_server()\n\nThe UAF bug is due to smb2_reconnect_server() accessing a session that\nis already being teared down by another thread that is executing\n__cifs_put_smb_ses(). This can happen when (a) the client has\nconnection to the server but no session or (b) another thread ends up\nsetting @ses->ses_status again to something different than\nSES_EXITING.\n\nTo fix this, we need to make sure to unconditionally set\n@ses->ses_status to SES_EXITING and prevent any other threads from\nsetting a new status while we're still tearing it down.\n\nThe following can be reproduced by adding some delay to right after\nthe ipc is freed in __cifs_put_smb_ses() - which will give\nsmb2_reconnect_server() worker a chance to run and then accessing\n@ses->ipc:\n\nkinit ...\nmount.cifs //srv/share /mnt/1 -o sec=krb5,nohandlecache,echo_interval=10\n[disconnect srv]\nls /mnt/1 &>/dev/null\nsleep 30\nkdestroy\n[reconnect srv]\nsleep 10\numount /mnt/1\n...\nCIFS: VFS: Verify user has a krb5 ticket and keyutils is installed\nCIFS: VFS: \\\\srv Send error in SessSetup = -126\nCIFS: VFS: Verify user has a krb5 ticket and keyutils is installed\nCIFS: VFS: \\\\srv Send error in SessSetup = -126\ngeneral protection fault, probably for non-canonical address\n0x6b6b6b6b6b6b6b6b: 0000 [#1] PREEMPT SMP NOPTI\nCPU: 3 PID: 50 Comm: kworker/3:1 Not tainted 6.9.0-rc2 #1\nHardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-1.fc39\n04/01/2014\nWorkqueue: cifsiod smb2_reconnect_server [cifs]\nRIP: 0010:__list_del_entry_valid_or_report+0x33/0xf0\nCode: 4f 08 48 85 d2 74 42 48 85 c9 74 59 48 b8 00 01 00 00 00 00 ad\nde 48 39 c2 74 61 48 b8 22 01 00 00 00 00 74 69 <48> 8b 01 48 39 f8 75\n7b 48 8b 72 08 48 39 c6 0f 85 88 00 00 00 b8\nRSP: 0018:ffffc900001bfd70 EFLAGS: 00010a83\nRAX: dead000000000122 RBX: ffff88810da53838 RCX: 6b6b6b6b6b6b6b6b\nRDX: 6b6b6b6b6b6b6b6b RSI: ffffffffc02f6878 RDI: ffff88810da53800\nRBP: ffff88810da53800 R08: 0000000000000001 R09: 0000000000000000\nR10: 0000000000000000 R11: 0000000000000001 R12: ffff88810c064000\nR13: 0000000000000001 R14: ffff88810c064000 R15: ffff8881039cc000\nFS: 0000000000000000(0000) GS:ffff888157c00000(0000)\nknlGS:0000000000000000\nCS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 00007fe3728b1000 CR3: 000000010caa4000 CR4: 0000000000750ef0\nPKRU: 55555554\nCall Trace:\n <TASK>\n ? die_addr+0x36/0x90\n ? exc_general_protection+0x1c1/0x3f0\n ? asm_exc_general_protection+0x26/0x30\n ? __list_del_entry_valid_or_report+0x33/0xf0\n __cifs_put_smb_ses+0x1ae/0x500 [cifs]\n smb2_reconnect_server+0x4ed/0x710 [cifs]\n process_one_work+0x205/0x6b0\n worker_thread+0x191/0x360\n ? __pfx_worker_thread+0x10/0x10\n kthread+0xe2/0x110\n ? __pfx_kthread+0x10/0x10\n ret_from_fork+0x34/0x50\n ? __pfx_kthread+0x10/0x10\n ret_from_fork_asm+0x1a/0x30\n </TASK>"}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: smb: cliente: corrige UAF en smb2_reconnect_server() El error de UAF se debe a que smb2_reconnect_server() accede a una sesi\u00f3n que ya est\u00e1 siendo cancelada por otro hilo que est\u00e1 ejecutando __cifs_put_smb_ses(). Esto puede suceder cuando (a) el cliente tiene conexi\u00f3n al servidor pero no tiene sesi\u00f3n o (b) otro hilo termina configurando @ses-&gt;ses_status nuevamente en algo diferente a SES_EXITING. Para solucionar este problema, debemos asegurarnos de establecer incondicionalmente @ses-&gt;ses_status en SES_EXITING y evitar que otros hilos establezcan un nuevo estado mientras todav\u00eda lo estamos derribando. Lo siguiente se puede reproducir agregando algo de retraso justo despu\u00e9s de que se libera el ipc en __cifs_put_smb_ses(), lo que le dar\u00e1 al trabajador smb2_reconnect_server() la oportunidad de ejecutarse y luego acceder a @ses-&gt;ipc: kinit ... mount.cifs // srv/share /mnt/1 -o sec=krb5,nohandlecache,echo_interval=10 [disconnect srv] ls /mnt/1 &amp;&gt;/dev/null dormir 30 kdestroy [reconnect srv] sleep 10 umount /mnt/1 ... CIFS: VFS: Verifique que el usuario tenga un ticket krb5 y keyutils est\u00e9 instalado CIFS: VFS: \\\\srv Enviar error en SessSetup = -126 CIFS: VFS: Verifique que el usuario tenga un ticket krb5 y keyutils est\u00e9 instalado CIFS: VFS: \\\\srv Enviar error en SessSetup = -126 fallo de protecci\u00f3n general, probablemente para direcci\u00f3n no can\u00f3nica 0x6b6b6b6b6b6b6b6b: 0000 [#1] PREEMPT SMP NOPTI CPU: 3 PID: 50 Comm: kworker/3:1 Not tainted 6.9.0-rc2 #1 Nombre de hardware : PC est\u00e1ndar QEMU (Q35 + ICH9, 2009), BIOS 1.16.3-1.fc39 01/04/2014 Cola de trabajo: cifsiod smb2_reconnect_server [cifs] RIP: 0010:__list_del_entry_valid_or_report+0x33/0xf0 C\u00f3digo: 4f 08 48 85 d2 4 42 48 85 c9 74 59 48 b8 00 01 00 00 00 00 ad de 48 39 c2 74 61 48 b8 22 01 00 00 00 00 74 69 &lt;48&gt; 8b 01 48 39 f8 75 7b 48 8b 72 08 48 9 c6 0f 85 88 00 00 00 b8 RSP: 0018:ffffc900001bfd70 EFLAGS: 00010a83 RAX: muerto000000000122 RBX: ffff88810da53838 RCX: 6b6b6b6b6b6b6b6b RDX: 6b6b6b6b6b6b6b6b RSI: ffffffffc02f6878 RDI: ffff88810da53800 RBP: ffff88810da53800 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000001 R12: ffff88810c064000 R13: 0000000000000001 R14: ffff88810c064000 R15: ffff8881039cc000 FS: 0000000000000000(0000) GS:ffff888157c00000(0000) knlGS:00000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe3728b1000 CR3: 000000010caa4000 CR4: 0000000000750ef0 PKRU: 55555554 Seguimiento de llamadas: &lt; TASK&gt; ? die_addr+0x36/0x90? exc_general_protection+0x1c1/0x3f0? asm_exc_general_protection+0x26/0x30? __list_del_entry_valid_or_report+0x33/0xf0 __cifs_put_smb_ses+0x1ae/0x500 [cifs] smb2_reconnect_server+0x4ed/0x710 [cifs] Process_one_work+0x205/0x6b0 worker_thread+0x191/0x360 ? __pfx_worker_thread+0x10/0x10 kthread+0xe2/0x110 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x34/0x50 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 "}], "id": "CVE-2024-35870", "lastModified": "2026-08-04T11:18:03.407", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 9.8, "baseSeverity": "CRITICAL", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}, {"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "NONE", "baseScore": 4.4, "baseSeverity": "MEDIUM", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "privilegesRequired": "HIGH", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N", "version": "3.1"}, "exploitabilityScore": 0.8, "impactScore": 3.6, "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2024-35870", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2024-06-17T17:38:54.896093Z", "version": "2.0.3"}}]}, "published": "2024-05-19T09:15:08.427", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/24a9799aa8efecd0eb55a75e35f9d8e6400063aa"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/45f2beda1f1bc3d962ec07db1ccc3197c25499a5"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/6202996a1c1887e83d0b3b0fcd86d0e5e6910ea0"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/755fe68cd4b59e1d2a2dd3286177fd4404f57fed"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/24a9799aa8efecd0eb55a75e35f9d8e6400063aa"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/45f2beda1f1bc3d962ec07db1ccc3197c25499a5"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/6202996a1c1887e83d0b3b0fcd86d0e5e6910ea0"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "url": "https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-416"}], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}]}

{"affected_release": [{"advisory": "RHSA-2024:4349", "cpe": "cpe:/a:redhat:enterprise_linux:9", "package": "kernel-0:5.14.0-427.24.1.el9_4", "product_name": "Red Hat Enterprise Linux 9", "release_date": "2024-07-08T00:00:00Z"}, {"advisory": "RHSA-2024:4349", "cpe": "cpe:/o:redhat:enterprise_linux:9", "package": "kernel-0:5.14.0-427.24.1.el9_4", "product_name": "Red Hat Enterprise Linux 9", "release_date": "2024-07-08T00:00:00Z"}, {"advisory": "RHSA-2024:4108", "cpe": "cpe:/a:redhat:rhel_eus:9.2", "package": "kernel-0:5.14.0-284.71.1.el9_2", "product_name": "Red Hat Enterprise Linux 9.2 Extended Update Support", "release_date": "2024-06-26T00:00:00Z"}, {"advisory": "RHSA-2024:4106", "cpe": "cpe:/a:redhat:rhel_eus:9.2::nfv", "package": "kernel-rt-0:5.14.0-284.71.1.rt14.356.el9_2", "product_name": "Red Hat Enterprise Linux 9.2 Extended Update Support", "release_date": "2024-06-26T00:00:00Z"}], "bugzilla": {"description": "kernel: smb: client: fix UAF in smb2_reconnect_server()", "id": "2281740", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2281740"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.9", "cvss3_scoring_vector": "CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H", "status": "verified"}, "cwe": "CWE-416", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nsmb: client: fix UAF in smb2_reconnect_server()\nThe UAF bug is due to smb2_reconnect_server() accessing a session that\nis already being teared down by another thread that is executing\n__cifs_put_smb_ses(). This can happen when (a) the client has\nconnection to the server but no session or (b) another thread ends up\nsetting @ses->ses_status again to something different than\nSES_EXITING.\nTo fix this, we need to make sure to unconditionally set\n@ses->ses_status to SES_EXITING and prevent any other threads from\nsetting a new status while we're still tearing it down.\nThe following can be reproduced by adding some delay to right after\nthe ipc is freed in __cifs_put_smb_ses() - which will give\nsmb2_reconnect_server() worker a chance to run and then accessing\n@ses->ipc:\nkinit ...\nmount.cifs //srv/share /mnt/1 -o sec=krb5,nohandlecache,echo_interval=10\n[disconnect srv]\nls /mnt/1 &>/dev/null\nsleep 30\nkdestroy\n[reconnect srv]\nsleep 10\numount /mnt/1\n...\nCIFS: VFS: Verify user has a krb5 ticket and keyutils is installed\nCIFS: VFS: \\\\srv Send error in SessSetup = -126\nCIFS: VFS: Verify user has a krb5 ticket and keyutils is installed\nCIFS: VFS: \\\\srv Send error in SessSetup = -126\ngeneral protection fault, probably for non-canonical address\n0x6b6b6b6b6b6b6b6b: 0000 [#1] PREEMPT SMP NOPTI\nCPU: 3 PID: 50 Comm: kworker/3:1 Not tainted 6.9.0-rc2 #1\nHardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-1.fc39\n04/01/2014\nWorkqueue: cifsiod smb2_reconnect_server [cifs]\nRIP: 0010:__list_del_entry_valid_or_report+0x33/0xf0\nCode: 4f 08 48 85 d2 74 42 48 85 c9 74 59 48 b8 00 01 00 00 00 00 ad\nde 48 39 c2 74 61 48 b8 22 01 00 00 00 00 74 69 <48> 8b 01 48 39 f8 75\n7b 48 8b 72 08 48 39 c6 0f 85 88 00 00 00 b8\nRSP: 0018:ffffc900001bfd70 EFLAGS: 00010a83\nRAX: dead000000000122 RBX: ffff88810da53838 RCX: 6b6b6b6b6b6b6b6b\nRDX: 6b6b6b6b6b6b6b6b RSI: ffffffffc02f6878 RDI: ffff88810da53800\nRBP: ffff88810da53800 R08: 0000000000000001 R09: 0000000000000000\nR10: 0000000000000000 R11: 0000000000000001 R12: ffff88810c064000\nR13: 0000000000000001 R14: ffff88810c064000 R15: ffff8881039cc000\nFS: 0000000000000000(0000) GS:ffff888157c00000(0000)\nknlGS:0000000000000000\nCS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 00007fe3728b1000 CR3: 000000010caa4000 CR4: 0000000000750ef0\nPKRU: 55555554\nCall Trace:\n<TASK>\n? die_addr+0x36/0x90\n? exc_general_protection+0x1c1/0x3f0\n? asm_exc_general_protection+0x26/0x30\n? __list_del_entry_valid_or_report+0x33/0xf0\n__cifs_put_smb_ses+0x1ae/0x500 [cifs]\nsmb2_reconnect_server+0x4ed/0x710 [cifs]\nprocess_one_work+0x205/0x6b0\nworker_thread+0x191/0x360\n? __pfx_worker_thread+0x10/0x10\nkthread+0xe2/0x110\n? __pfx_kthread+0x10/0x10\nret_from_fork+0x34/0x50\n? __pfx_kthread+0x10/0x10\nret_from_fork_asm+0x1a/0x30\n</TASK>", "A flaw was found in the smb client in the Linux kernel. A potential use-after-free error was seen in the smb2_reconnect_server() function. This issue can lead to the crash of a client user session."], "mitigation": {"lang": "en:us", "value": "To mitigate this issue, prevent module cifs from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically."}, "name": "CVE-2024-35870", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Will not fix", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Will not fix", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2024-05-19T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2024-35870\nhttps://nvd.nist.gov/vuln/detail/CVE-2024-35870\nhttps://lore.kernel.org/linux-cve-announce/2024051940-CVE-2024-35870-3c02@gregkh/T"], "statement": "This vulnerability considered being Moderate impact because of limitations for attack scenario.", "threat_severity": "Moderate"}

{}