Bug 2536694 (CVE-2026-90175)

Summary: CVE-2026-90175 kernel: smb: server: fix leak of ksmbd_ipc_login_request_ext() returned buffer
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in the ksmbd server component of the Linux kernel. This memory leak occurs because a buffer returned by `ksmbd_ipc_login_request_ext()` is not freed unconditionally after `ksmbd_alloc_user()` calls. A remote attacker could potentially exploit this flaw to cause a denial of service by exhausting available memory resources.
Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-09-17 19:07:28 UTC
In the Linux kernel, the following vulnerability has been resolved:

smb: server: fix leak of ksmbd_ipc_login_request_ext() returned buffer

Free it unconditionally after ksmbd_alloc_user() calls.

kmemleak splat:
  unreferenced object 0xffff888103b83540 (size 192):
    comm "pool-0", pid 16970, jiffies 4377290937
    hex dump (first 32 bytes):
      00 00 00 00 01 00 00 00 00 00 00 00 00 00 00 00  ................
      00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    backtrace (crc 408ccc66):
      __kvmalloc_node_noprof+0x730/0x920
      handle_generic_event+0xec/0x1a0 [ksmbd]
      genl_family_rcv_msg_doit+0xe0/0x130
      genl_rcv_msg+0x181/0x290
      netlink_rcv_skb+0x4f/0x100
      genl_rcv+0x28/0x40
      netlink_unicast+0x1e6/0x2c0
      netlink_sendmsg+0x20a/0x450
      ____sys_sendmsg+0x2e8/0x310
      ___sys_sendmsg+0x78/0xc0
      __sys_sendmsg+0x63/0xc0
      do_syscall_64+0xa1/0x670
      entry_SYSCALL_64_after_hwframe+0x76/0x7e