{"id":"CVE-2025-37750","title":"smb: client: fix UAF in decryption with multichannel","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix UAF in decryption with multichannel\n\nAfter commit f7025d861694 (\"smb: client: allocate crypto only for\nprimary server\") and commit b0abcd65ec54 (\"smb: …","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= c8c6af46286a513769650935ff858fc67cf51a6d < 08160de2a65227e5b64fcb6765cd936ec384ee93","Linux >= b0abcd65ec545701b8793e12bc27dc98042b151a < aa5a1e4b882964eb79d5b5d1d1e8a1a5efbb1d15","Linux >= b0abcd65ec545701b8793e12bc27dc98042b151a < e859b216d94668bc66330e61be201234f4413d1a","Linux >= b0abcd65ec545701b8793e12bc27dc98042b151a < 950557922c1298464749c216d8763e97faf5d0a6","Linux >= b0abcd65ec545701b8793e12bc27dc98042b151a < 9502dd5c7029902f4a425bf959917a5a9e7c0e50","Linux 8f14a476abba13144df5434871a7225fd29af633","Linux ef51c0d544b1518b35364480317ab6d3468f205d","Linux bce966530fd5542bbb422cb45ecb775f7a1a6bc3","Linux 0809fb86ad13b29e1d6d491364fc7ea4fb545995","Linux 538c26d9bf70c90edc460d18c81008a4e555925a","Linux >= 5.10.237 < 5.11","Linux >= 5.15.181 < 5.16","Linux >= 6.1.128 < 6.2","Linux >= 6.11.4 < 6.12","Linux 6.12"],"published":"2025-05-01","updated":"2026-10-21","sourceUpdated":"2026-10-21T12:36:26.033Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2025-37750","references":[{"url":"https://git.kernel.org/stable/c/08160de2a65227e5b64fcb6765cd936ec384ee93"},{"url":"https://git.kernel.org/stable/c/aa5a1e4b882964eb79d5b5d1d1e8a1a5efbb1d15"},{"url":"https://git.kernel.org/stable/c/e859b216d94668bc66330e61be201234f4413d1a"},{"url":"https://git.kernel.org/stable/c/950557922c1298464749c216d8763e97faf5d0a6"},{"url":"https://git.kernel.org/stable/c/9502dd5c7029902f4a425bf959917a5a9e7c0e50"}],"tags":["cve.org"],"epss":0.00468,"epssPercentile":0.40372,"ingestedAt":"2026-10-21T12:48:53.712Z","slug":"CVE-2025-37750","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix UAF in decryption with multichannel\n\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.\n\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:\n\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>\n dump_stack_lvl+0x5d/0x80\n print_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\n kasan_report+0xdf/0x1a0\n ? gf128mul_4k_lle+0xba/0x110\n gf128mul_4k_lle+0xba/0x110\n ghash_update+0x189/0x210\n shash_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\n crypto_ahash_update+0x3c/0xc0\n gcm_hash_assoc_remain_continue+0x93/0xc0\n crypt_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]\n decrypt_raw_data+0x229/0x380 [cifs]\n ? __pfx_decrypt_raw_data+0x10/0x10 [cifs]\n ? __pfx_cifs_read_iter_from_socket+0x10/0x10 [cifs]\n smb3_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]\n cifs_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]\n kthread+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\n ret_from_fork+0x31/0x60\n ? __pfx_kthread+0x10/0x10\n ret_from_fork_asm+0x1a/0x30\n </TASK>\n\n## Affected\n\n- `Linux >= c8c6af46286a513769650935ff858fc67cf51a6d < 08160de2a65227e5b64fcb6765cd936ec384ee93`\n- `Linux >= b0abcd65ec545701b8793e12bc27dc98042b151a < aa5a1e4b882964eb79d5b5d1d1e8a1a5efbb1d15`\n- `Linux >= b0abcd65ec545701b8793e12bc27dc98042b151a < e859b216d94668bc66330e61be201234f4413d1a`\n- `Linux >= b0abcd65ec545701b8793e12bc27dc98042b151a < 950557922c1298464749c216d8763e97faf5d0a6`\n- `Linux >= b0abcd65ec545701b8793e12bc27dc98042b151a < 9502dd5c7029902f4a425bf959917a5a9e7c0e50`\n- `Linux 8f14a476abba13144df5434871a7225fd29af633`\n- `Linux ef51c0d544b1518b35364480317ab6d3468f205d`\n- `Linux bce966530fd5542bbb422cb45ecb775f7a1a6bc3`\n- `Linux 0809fb86ad13b29e1d6d491364fc7ea4fb545995`\n- `Linux 538c26d9bf70c90edc460d18c81008a4e555925a`\n- `Linux >= 5.10.237 < 5.11`\n- `Linux >= 5.15.181 < 5.16`\n- `Linux >= 6.1.128 < 6.2`\n- `Linux >= 6.11.4 < 6.12`\n- `Linux 6.12`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}