{"cve":"CVE-2025-38244","nvd":{"published":"2025-07-09T11:15:26.480","modified":"2026-10-15T22:18:36.430","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix potential deadlock when reconnecting channels\n\nFix cifs_signal_cifsd_for_reconnect() to take the correct lock order\nand prevent the following deadlock from happening\n\n======================================================\nWARNING: possible circular locking dependency detected\n6.16.0-rc3-build2+ #1301 Tainted: G S      W\n------------------------------------------------------\ncifsd/6055 is trying to acquire lock:\nffff88810ad56038 (&tcp_ses->srv_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0x134/0x200\n\nbut task is already holding lock:\nffff888119c64330 (&ret_buf->chan_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0xcf/0x200\n\nwhich lock already depends on the new lock.\n\nthe existing dependency chain (in reverse order) is:\n\n-> #2 (&ret_buf->chan_lock){+.+.}-{3:3}:\n       validate_chain+0x1cf/0x270\n       __lock_acquire+0x60e/0x780\n       lock_acquire.part.0+0xb4/0x1f0\n       _raw_spin_lock+0x2f/0x40\n       cifs_setup_session+0x81/0x4b0\n       cifs_get_smb_ses+0x771/0x900\n       cifs_mount_get_session+0x7e/0x170\n       cifs_mount+0x92/0x2d0\n       cifs_smb3_do_mount+0x161/0x460\n       smb3_get_tree+0x55/0x90\n       vfs_get_tree+0x46/0x180\n       do_new_mount+0x1b0/0x2e0\n       path_mount+0x6ee/0x740\n       do_mount+0x98/0xe0\n       __do_sys_mount+0x148/0x180\n       do_syscall_64+0xa4/0x260\n       entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\n-> #1 (&ret_buf->ses_lock){+.+.}-{3:3}:\n       validate_chain+0x1cf/0x270\n       __lock_acquire+0x60e/0x780\n       lock_acquire.part.0+0xb4/0x1f0\n       _raw_spin_lock+0x2f/0x40\n       cifs_match_super+0x101/0x320\n       sget+0xab/0x270\n       cifs_smb3_do_mount+0x1e0/0x460\n       smb3_get_tree+0x55/0x90\n       vfs_get_tree+0x46/0x180\n       do_new_mount+0x1b0/0x2e0\n       path_mount+0x6ee/0x740\n       do_mount+0x98/0xe0\n       __do_sys_mount+0x148/0x180\n       do_syscall_64+0xa4/0x260\n       entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\n-> #0 (&tcp_ses->srv_lock){+.+.}-{3:3}:\n       check_noncircular+0x95/0xc0\n       check_prev_add+0x115/0x2f0\n       validate_chain+0x1cf/0x270\n       __lock_acquire+0x60e/0x780\n       lock_acquire.part.0+0xb4/0x1f0\n       _raw_spin_lock+0x2f/0x40\n       cifs_signal_cifsd_for_reconnect+0x134/0x200\n       __cifs_reconnect+0x8f/0x500\n       cifs_handle_standard+0x112/0x280\n       cifs_demultiplex_thread+0x64d/0xbc0\n       kthread+0x2f7/0x310\n       ret_from_fork+0x2a/0x230\n       ret_from_fork_asm+0x1a/0x30\n\nother info that might help us debug this:\n\nChain exists of:\n  &tcp_ses->srv_lock --> &ret_buf->ses_lock --> &ret_buf->chan_lock\n\n Possible unsafe locking scenario:\n\n       CPU0                    CPU1\n       ----                    ----\n  lock(&ret_buf->chan_lock);\n                               lock(&ret_buf->ses_lock);\n                               lock(&ret_buf->chan_lock);\n  lock(&tcp_ses->srv_lock);\n\n *** DEADLOCK ***\n\n3 locks held by cifsd/6055:\n #0: ffffffff857de398 (&cifs_tcp_ses_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0x7b/0x200\n #1: ffff888119c64060 (&ret_buf->ses_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0x9c/0x200\n #2: ffff888119c64330 (&ret_buf->chan_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0xcf/0x200","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-667"],"references":["https://git.kernel.org/stable/c/711741f94ac3cf9f4e3aa73aa171e76d188c0819","https://git.kernel.org/stable/c/7f3ead8ebc0ef65b6c89a13912b4e80218425629","https://git.kernel.org/stable/c/c82c7041258d96e3286f6790ab700e4edd3cc9e3","https://git.kernel.org/stable/c/fe035dc78aa6ca8f862857d45beaf7a0e03206ca"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:04:28.436527499+00:00"},"epss":{"cve":"CVE-2025-38244","score":0.00252,"percentile":0.16524,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}