{"schema_version":"1.9.0","id":"CVE-2024-35870","published":"2024-05-19T08:34:28.419Z","modified":"2026-08-12T03:51:16.085909268Z","related":["ALSA-2024:4349","SUSE-SU-2024:2008-1","SUSE-SU-2024:2019-1","SUSE-SU-2024:2135-1","SUSE-SU-2024:2190-1","SUSE-SU-2024:2203-1","SUSE-SU-2024:2360-1","SUSE-SU-2024:2381-1","SUSE-SU-2024:2561-1","SUSE-SU-2025:20008-1","SUSE-SU-2025:20028-1"],"summary":"smb: client: fix UAF in smb2_reconnect_server()","details":"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>","affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"b327a717e506980399464e304e363f94f95eb7a1"},{"fixed":"755fe68cd4b59e1d2a2dd3286177fd4404f57fed"},{"fixed":"6202996a1c1887e83d0b3b0fcd86d0e5e6910ea0"},{"fixed":"45f2beda1f1bc3d962ec07db1ccc3197c25499a5"},{"fixed":"24a9799aa8efecd0eb55a75e35f9d8e6400063aa"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-35870.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.16.0"},{"fixed":"6.1.121"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.29"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.8.5"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-35870.json"}}],"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/24a9799aa8efecd0eb55a75e35f9d8e6400063aa"},{"type":"WEB","url":"https://git.kernel.org/stable/c/45f2beda1f1bc3d962ec07db1ccc3197c25499a5"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6202996a1c1887e83d0b3b0fcd86d0e5e6910ea0"},{"type":"WEB","url":"https://git.kernel.org/stable/c/755fe68cd4b59e1d2a2dd3286177fd4404f57fed"},{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/35xxx/CVE-2024-35870.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-35870"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/35xxx/CVE-2024-35870.json"},"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}