9.8

CVE-2024-50047: smb: client: fix UAF in async decryption

Modified
AliasesUBUNTU-CVE-2024-50047DEBIAN-CVE-2024-50047
Published 21-10-2024Last modified 05-08-2026

Vulnerability summary

CVE-2024-50047 is a critical (CVSS 9.8) Use After Free vulnerability in linux. EPSS estimates a 0.52% chance of exploitation in the next 30 days, higher than 44% of scored vulnerabilities.

Priority
Prioritisesevere

Severe, CVSS 9.8 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 1% (FIRST, 03-11-2026)

Source freshness unavailable

How is this decided?
CVSS score
9.8/10
010
Critical · v3.1 (CVE.org)
EPSS score
0.52%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 62 · Related 56
DLA-4076-1DLA-4178-1DSA-5860-1LSN-0113-1LSN-0115-1MGASA-2024-0344

Timeline

  1. 21-10-2024
    PublishedVulnerability first disclosed.
  2. 05-08-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix UAF in async decryption Doing an async decryption (large read) crashes with a slab-use-after-free way down in the crypto API. Reproducer: # mount.cifs -o ...,seal,esize=1 //srv/share /mnt # dd if=/mnt/largefile of=/dev/null ... [ 194.196391] ================================================================== [ 194.196844] BUG: KASAN: slab-use-after-free in gf128mul_4k_lle+0xc1/0x110 [ 194.197269] Read of size 8 at addr ffff888112bd0448 by task kworker/u77:2/899 [ 194.197707] [ 194.197818] CPU: 12 UID: 0 PID: 899 Comm: kworker/u77:2 Not tainted 6.11.0-lku-00028-gfca3ca14a17a-dirty #43 [ 194.198400] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.2-3-gd478f380-prebuilt.qemu.org 04/01/2014 [ 194.199046] Workqueue: smb3decryptd smb2_decrypt_offload [cifs] [ 194.200032] Call Trace: [ 194.200191] <TASK> [ 194.200327] dump_stack_lvl+0x4e/0x70 [ 194.200558] ? gf128mul_4k_lle+0xc1/0x110 [ 194.200809] print_report+0x174/0x505 [ 194.201040] ? __pfx__raw_spin_lock_irqsave+0x10/0x10 [ 194.201352] ? srso_return_thunk+0x5/0x5f [ 194.201604] ? __virt_addr_valid+0xdf/0x1c0 [ 194.201868] ? gf128mul_4k_lle+0xc1/0x110 [ 194.202128] kasan_report+0xc8/0x150 [ 194.202361] ? gf128mul_4k_lle+0xc1/0x110 [ 194.202616] gf128mul_4k_lle+0xc1/0x110 [ 194.202863] ghash_update+0x184/0x210 [ 194.203103] shash_ahash_update+0x184/0x2a0 [ 194.203377] ? __pfx_shash_ahash_update+0x10/0x10 [ 194.203651] ? srso_return_thunk+0x5/0x5f [ 194.203877] ? crypto_gcm_init_common+0x1ba/0x340 [ 194.204142] gcm_hash_assoc_remain_continue+0x10a/0x140 [ 194.204434] crypt_message+0xec1/0x10a0 [cifs] [ 194.206489] ? __pfx_crypt_message+0x10/0x10 [cifs] [ 194.208507] ? srso_return_thunk+0x5/0x5f [ 194.209205] ? srso_return_thunk+0x5/0x5f [ 194.209925] ? srso_return_thunk+0x5/0x5f [ 194.210443] ? srso_return_thunk+0x5/0x5f [ 194.211037] decrypt_raw_data+0x15f/0x250 [cifs] [ 194.212906] ? __pfx_decrypt_raw_data+0x10/0x10 [cifs] [ 194.214670] ? srso_return_thunk+0x5/0x5f [ 194.215193] smb2_decrypt_offload+0x12a/0x6c0 [cifs] This is because TFM is being used in parallel. Fix this by allocating a new AEAD TFM for async decryption, but keep the existing one for synchronous READ cases (similar to what is done in smb3_calc_signature()). Also remove the calls to aead_request_set_callback() and crypto_wait_req() since it's always going to be a synchronous operation.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.52%

Chance of exploitation in the next 30 days

Percentile

44%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.52% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu130 products
  • linux< 5.4.0-219.239 | < 5.15.0-143.153 | < 6.8.0-56.58
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 5.4.0-1148.158 | < 5.15.0-1087.94 | < 6.8.0-1025.27
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ 35cf94a397280b9e27576ac1480f631bdd3e7b70, < 8f14a476abba13144df5434871a7225fd29af633 | ≥ 35cf94a397280b9e27576ac1480f631bdd3e7b70, < ef51c0d544b1518b35364480317ab6d3468f205d | ≥ 35cf94a397280b9e27576ac1480f631bdd3e7b70, < bce966530fd5542bbb422cb45ecb775f7a1a6bc3 | ≥ 35cf94a397280b9e27576ac1480f631bdd3e7b70, < 0809fb86ad13b29e1d6d491364fc7ea4fb545995 | ≥ 35cf94a397280b9e27576ac1480f631bdd3e7b70, < 538c26d9bf70c90edc460d18c81008a4e555925a | ≥ 35cf94a397280b9e27576ac1480f631bdd3e7b70, < b0abcd65ec545701b8793e12bc27dc98042b151a | 5.4
  • linux_kernel< 6.6.57 | ≥ 6.7, < 6.11.4
Debian1 product
  • linux< 6.1.128-1 | < 6.11.4-1

3 vendors · 133 products

References

41 links
Show all 41 references