{
  "threat_severity" : "Important",
  "public_date" : "2025-05-01T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: smb: client: fix UAF in decryption with multichannel",
    "id" : "2363341",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2363341"
  },
  "cvss3" : {
    "cvss3_base_score" : "7.3",
    "cvss3_scoring_vector" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/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 decryption with multichannel\nAfter commit f7025d861694 (\"smb: client: allocate crypto only for\nprimary server\") and commit b0abcd65ec54 (\"smb: client: fix UAF in\nasync decryption\"), the channels started reusing AEAD TFM from primary\nchannel to perform synchronous decryption, but that can't done as\nthere could be multiple cifsd threads (one per channel) simultaneously\naccessing it to perform decryption.\nThis fixes the following KASAN splat when running fstest generic/249\nwith 'vers=3.1.1,multichannel,max_channels=4,seal' against Windows\nServer 2022:\nBUG: KASAN: slab-use-after-free in gf128mul_4k_lle+0xba/0x110\nRead of size 8 at addr ffff8881046c18a0 by task cifsd/986\nCPU: 3 UID: 0 PID: 986 Comm: cifsd Not tainted 6.15.0-rc1 #1\nPREEMPT(voluntary)\nHardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-3.fc41\n04/01/2014\nCall Trace:\n<TASK>\ndump_stack_lvl+0x5d/0x80\nprint_report+0x156/0x528\n? gf128mul_4k_lle+0xba/0x110\n? __virt_addr_valid+0x145/0x300\n? __phys_addr+0x46/0x90\n? gf128mul_4k_lle+0xba/0x110\nkasan_report+0xdf/0x1a0\n? gf128mul_4k_lle+0xba/0x110\ngf128mul_4k_lle+0xba/0x110\nghash_update+0x189/0x210\nshash_ahash_update+0x295/0x370\n? __pfx_shash_ahash_update+0x10/0x10\n? __pfx_shash_ahash_update+0x10/0x10\n? __pfx_extract_iter_to_sg+0x10/0x10\n? ___kmalloc_large_node+0x10e/0x180\n? __asan_memset+0x23/0x50\ncrypto_ahash_update+0x3c/0xc0\ngcm_hash_assoc_remain_continue+0x93/0xc0\ncrypt_message+0xe09/0xec0 [cifs]\n? __pfx_crypt_message+0x10/0x10 [cifs]\n? _raw_spin_unlock+0x23/0x40\n? __pfx_cifs_readv_from_socket+0x10/0x10 [cifs]\ndecrypt_raw_data+0x229/0x380 [cifs]\n? __pfx_decrypt_raw_data+0x10/0x10 [cifs]\n? __pfx_cifs_read_iter_from_socket+0x10/0x10 [cifs]\nsmb3_receive_transform+0x837/0xc80 [cifs]\n? __pfx_smb3_receive_transform+0x10/0x10 [cifs]\n? __pfx___might_resched+0x10/0x10\n? __pfx_smb3_is_transform_hdr+0x10/0x10 [cifs]\ncifs_demultiplex_thread+0x692/0x1570 [cifs]\n? __pfx_cifs_demultiplex_thread+0x10/0x10 [cifs]\n? rcu_is_watching+0x20/0x50\n? rcu_lockdep_current_cpu_online+0x62/0xb0\n? find_held_lock+0x32/0x90\n? kvm_sched_clock_read+0x11/0x20\n? local_clock_noinstr+0xd/0xd0\n? trace_irq_enable.constprop.0+0xa8/0xe0\n? __pfx_cifs_demultiplex_thread+0x10/0x10 [cifs]\nkthread+0x1fe/0x380\n? kthread+0x10f/0x380\n? __pfx_kthread+0x10/0x10\n? local_clock_noinstr+0xd/0xd0\n? ret_from_fork+0x1b/0x60\n? local_clock+0x15/0x30\n? lock_release+0x29b/0x390\n? rcu_is_watching+0x20/0x50\n? __pfx_kthread+0x10/0x10\nret_from_fork+0x31/0x60\n? __pfx_kthread+0x10/0x10\nret_from_fork_asm+0x1a/0x30\n</TASK>", "A use-after-free (UAF) vulnerability was found in the Linux kernel's SMB client functionality. A local attacker with permissions to connect to arbitrary SMB servers with precise timing could exploit this flaw to alter system memory, leading to denials of service, alteration of sensitive memory locations, or privilege escalation." ],
  "statement" : "This vulnerability exists in how the SMB client manages cryptography for multi-channel connections. When using multi-channel connections, there is a possibility that a race condition will occur in separate threads. In that case, it is possible for one thread to free memory related to cryptography before another thread accesses it. An attacker could leverage that vulnerability to modify kernel memory, which could result in an escalation of privileges as well as potentially impacting system stability and integrity.\nThe changes in multichannel SMB client cryptography management that led to this vulnerability are not present in Red Hat Enterprise Linux prior to 9.6.",
  "affected_release" : [ {
    "product_name" : "Red Hat Enterprise Linux 10",
    "release_date" : "2025-06-16T00:00:00Z",
    "advisory" : "RHSA-2025:9079",
    "cpe" : "cpe:/o:redhat:enterprise_linux:10.0",
    "package" : "kernel-0:6.12.0-55.17.1.el10_0"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2025-06-16T00:00:00Z",
    "advisory" : "RHSA-2025:9080",
    "cpe" : "cpe:/a:redhat:enterprise_linux:9",
    "package" : "kernel-0:5.14.0-570.22.1.el9_6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2025-06-16T00:00:00Z",
    "advisory" : "RHSA-2025:9080",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9",
    "package" : "kernel-0:5.14.0-570.22.1.el9_6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2025-06-23T00:00:00Z",
    "advisory" : "RHSA-2025:9393",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9",
    "package" : "kpatch-patch"
  } ],
  "package_state" : [ {
    "product_name" : "Red Hat Enterprise Linux 6",
    "fix_state" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Not affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Not affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Not affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2025-37750\nhttps://nvd.nist.gov/vuln/detail/CVE-2025-37750\nhttps://lore.kernel.org/linux-cve-announce/2025050136-CVE-2025-37750-fdd8@gregkh/T" ],
  "name" : "CVE-2025-37750",
  "mitigation" : {
    "value" : "Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.",
    "lang" : "en:us"
  },
  "csaw" : false
}