High severity · published Dec 27, 2024
CVE-2024-56631
scsi: sg: Fix slab-use-after-free read in sg_release()
7.8
CVSS
0.3%
EPSS
No
On KEV
Description
In the Linux kernel, the following vulnerability has been resolved: scsi: sg: Fix slab-use-after-free read in sg_release() Fix a use-after-free bug in sg_release(), detected by syzbot with KASAN: BUG: KASAN: slab-use-after-free in lock_release+0x151/0xa30 kernel/locking/lockdep.c:5838 __mutex_unlock_slowpath+0xe2/0x750 kernel/locking/mutex.c:912 sg_release+0x1f4/0x2e0 drivers/scsi/sg.c:407 In sg_release(), the function kref_put(&sfp->f_ref, sg_remove_sfp) is called before releasing the open_rel_lock mutex. The kref_put() call may decrement the reference count of sfp to zero, triggering its cleanup through sg_remove_sfp(). This cleanup includes scheduling deferred work via sg_remove_sfp_usercontext(), which ultimately frees sfp. After kref_put(), sg_release() continues to unlock open_rel_lock and may reference sfp or sdp. If sfp has already been freed, this results in a slab-use-after-free error. Move the kref_put(&sfp->f_ref, sg_remove_sfp) call after unlocking the open_rel_lock mutex. This ensures: - No references to sfp or sdp occur after the reference count is decremented. - Cleanup functions such as sg_remove_sfp() and sg_remove_sfp_usercontext() can safely execute without impacting the mutex handling in sg_release(). The fix has been tested and validated by syzbot. This patch closes the bug reported at the following syzkaller link and ensures proper sequencing of resource cleanup and mutex operations, eliminating the risk of use-after-free errors in sg_release().
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 21% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
KE
Kernel · Linux
3.16.85 before 6.6.66; 6.7 before 6.12.5; 6.13 · source: NVD
LI
Linux · Linux
cc833acbee9db5ca8c6162b015b4c93863c6f821 before e19acb1926c4a1f30ee1ec84d8afba2d975bd534; cc833acbee9db5ca8c6162b015b4c93863c6f821 before 285ce1f89f8d414e7eecab5ef5118cd512596318; cc833acbee9db5ca8c6162b015b4c93863c6f821 before 198b89dd5a595ee3f96e5ce5c448b0484cd0e53c; cc833acbee9db5ca8c6162b015b4c93863c6f821 before 275b8347e21ab8193e93223a8394a806e4ba8918; cc833acbee9db5ca8c6162b015b4c93863c6f821 before 59b30afa578637169e2819536bb66459fdddc39d; cc833acbee9db5ca8c6162b015b4c93863c6f821 before 1f5e2f1ca5875728fcf62bc1a054707444ab4960; +4 more · source: vendor
SS
SIMATIC S7-1500 CPU 1518-4 PN/DP MFP · Siemens
V3.1.6; V3.1.7; V3.1.6; V3.1.7 · source: CISA
SS
SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP · Siemens
V3.1.6; V3.1.7; V3.1.6; V3.1.7 · source: CISA
SS
In the news
VulnerabilityHigh
Siemens SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP
View CSAF Summary Multiple vulnerabilities have been identified in the additional GNU/Linux subsystem of the firmware version V3.1.6 for the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP (incl. SIPLUS variant). Siemens is preparing fix versions and recommends specific countermeasures for products where fixes are not, or not yet available. The following versions of Siemens SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP are affected: SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) vers:intdot/>=3.1.6 (CVE-2021-41617, CVE-2023-28531, CVE-2023-51384, CVE-2023-52927, CVE-2024-26783, CVE-2024-27056, CVE-2024-28956, CVE-2024-36903, CVE-2024-36927, CVE-2024-42079, CVE-2024-46786, CVE-2024-47736, CVE-2024-47809, CVE-2024-49968, CVE-2024-49994, CVE-2024-49998, CVE-2024-50014, CVE-2024-50063, CVE-2024-50164, CVE-2024-50298, CVE-2024-53124, CVE-2024-53170, CVE-2024-54458, CVE-2024-56631, CVE-2024-56703, CVE-2024-56719, CVE-2024-57917, CVE-2024-57924, CVE-2024-57973, CVE-2024-57977, CVE-2024-57979, CVE-2024-58011, CVE-2024-58016, CVE-2024-58020, CVE-2024-58056, CVE-2024-58058, CVE-2024-58061, CVE-2024-58086, CVE-2025-21645, CVE-2025-21648, CVE-2025-21655, CVE-2025-21676, CVE-2025-21682, CVE-2025-21702, CVE-2025-21705, CVE-2025-21706, CVE-2025-21707, CVE-2025-21718, CVE-2025-21731, CVE-2025-21745, CVE-2025-21758, CVE-2025-21760, CVE-2025-21764, CVE-2025-21765, CVE-2025-21780, CVE-2025-21795, CVE-2025-21796, CVE-2025-21802, CVE-2025-21814, CVE-2025-21846, CVE-2025-21853, CVE-2...
Jul 28, 2026·CISA Advisories