CVE-2023-52757: smb: client: fix potential deadlock when releasing mids
Vulnerability summary
CVE-2023-52757 is a high (CVSS 7.8) Use After Free vulnerability in debian debian_linux. EPSS estimates a 0.19% chance of exploitation in the next 30 days, higher than 8.3% of scored vulnerabilities.
Not severe (CVSS 7.8, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 33 · Related 31Timeline
- 21-05-2024PublishedVulnerability first disclosed.
- 23-05-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: smb: client: fix potential deadlock when releasing mids All release_mid() callers seem to hold a reference of @mid so there is no need to call kref_put(&mid->refcount, __release_mid) under @server->mid_lock spinlock. If they don't, then an use-after-free bug would have occurred anyways. By getting rid of such spinlock also fixes a potential deadlock as shown below CPU 0 CPU 1 ------------------------------------------------------------------ cifs_demultiplex_thread() cifs_debug_data_proc_show() release_mid() spin_lock(&server->mid_lock); spin_lock(&cifs_tcp_ses_lock) spin_lock(&server->mid_lock) __release_mid() smb2_find_smb_tcon() spin_lock(&cifs_tcp_ses_lock) *deadlock*
CVSS metrics
3 scores · 3 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.19%
Chance of exploitation in the next 30 days
Percentile
8%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.19% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-416Use After FreeThe product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
- CWE-667Improper LockingThe product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.
Affected systems
Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu115 products
- linux< 4.15.0-240.252 | < 5.4.0-220.240 | < 5.15.0-144.157
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws< 4.15.0-1183.196 | < 5.4.0-1149.159 | < 5.15.0-1088.95
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Debian2 products
- linux< 6.1.64-1 | < 6.6.8-1
- debian_linuxEOL11.0
Linux2 products
- linux≥ 7b71843fa7028475b052107664cbe120156a2cfc, < 99f476e27aad5964ab13777d84fda67d1356dec1 | ≥ 7b71843fa7028475b052107664cbe120156a2cfc, < ce49569079a9d4cad26c0f1d4653382fd9a5ca7a | ≥ 7b71843fa7028475b052107664cbe120156a2cfc, < 9eb44db68c5b7f5aa22b8fc7de74a3e2e08d1f29 | ≥ 7b71843fa7028475b052107664cbe120156a2cfc, < b9bb9607b1fc12fca51f5632da25b36975f599bf | ≥ 7b71843fa7028475b052107664cbe120156a2cfc, < c1a5962f1462b64fe7b69f20a4b6af8067bc2d26 | ≥ 7b71843fa7028475b052107664cbe120156a2cfc, < e6322fd177c6885a21dd4609dc5e5c973d1a2eb7 | 9871dea42034ee6e73bb2b97ba0284d3d462b230 | ≥ 5.4.6, < 5.5 | 5.5
- linux_kernel< 5.10.237 | ≥ 5.11, < 5.15.181 | ≥ 5.16, < 6.1.64 | ≥ 6.2, < 6.5.13 | ≥ 6.6, < 6.6.3
3 vendors · 119 products
