CVE-2023-54112: kcm: Fix memory leak in error path of kcm_sendmsg()
Vulnerability summary
CVE-2023-54112 is a medium (CVSS 6.8) vulnerability in linux. EPSS estimates a 0.21% chance of exploitation in the next 30 days, higher than 11.2% of scored vulnerabilities.
Not severe (CVSS 6.8, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 9 · Related 9Timeline
- 24-12-2025PublishedVulnerability first disclosed.
- 11-05-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: kcm: Fix memory leak in error path of kcm_sendmsg() syzbot reported a memory leak like below: BUG: memory leak unreferenced object 0xffff88810b088c00 (size 240): comm "syz-executor186", pid 5012, jiffies 4294943306 (age 13.680s) hex dump (first 32 bytes): 00 89 08 0b 81 88 ff ff 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: [<ffffffff83e5d5ff>] __alloc_skb+0x1ef/0x230 net/core/skbuff.c:634 [<ffffffff84606e59>] alloc_skb include/linux/skbuff.h:1289 [inline] [<ffffffff84606e59>] kcm_sendmsg+0x269/0x1050 net/kcm/kcmsock.c:815 [<ffffffff83e479c6>] sock_sendmsg_nosec net/socket.c:725 [inline] [<ffffffff83e479c6>] sock_sendmsg+0x56/0xb0 net/socket.c:748 [<ffffffff83e47f55>] ____sys_sendmsg+0x365/0x470 net/socket.c:2494 [<ffffffff83e4c389>] ___sys_sendmsg+0xc9/0x130 net/socket.c:2548 [<ffffffff83e4c536>] __sys_sendmsg+0xa6/0x120 net/socket.c:2577 [<ffffffff84ad7bb8>] do_syscall_x64 arch/x86/entry/common.c:50 [inline] [<ffffffff84ad7bb8>] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 [<ffffffff84c0008b>] entry_SYSCALL_64_after_hwframe+0x63/0xcd In kcm_sendmsg(), kcm_tx_msg(head)->last_skb is used as a cursor to append newly allocated skbs to 'head'. If some bytes are copied, an error occurred, and jumped to out_error label, 'last_skb' is left unmodified. A later kcm_sendmsg() will use an obsoleted 'last_skb' reference, corrupting the 'head' frag_list and causing the leak. This patch fixes this issue by properly updating the last allocated skb in 'last_skb'.
CVSS metrics
1 score · 1 source · 1 versionEPSS trend
Probability
0.21%
Chance of exploitation in the next 30 days
Percentile
11%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.21% 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 causeNo weakness data has been published for this record.
Affected systems
Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu123 products
- linuxAll versions (No fix recorded) | < 5.4.0-169.187 | < 5.15.0-94.104
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded) | < 5.4.0-1116.126 | < 5.15.0-1053.58
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Debian1 product
- linux< 6.1.55-1 | < 6.5.6-1
Linux1 product
- linux≥ ab7ac4eb9832e32a09f4e8042705484d2fb0aad3, < 8dc7eb757b1652b82725f32e0c89a1e9f6c0e13b | ≥ ab7ac4eb9832e32a09f4e8042705484d2fb0aad3, < 5e5554389397e98fafb9efe395d8b4830dd5f042 | ≥ ab7ac4eb9832e32a09f4e8042705484d2fb0aad3, < 479c71cda14b3c3a6515773faa39055333eaa2b7 | ≥ ab7ac4eb9832e32a09f4e8042705484d2fb0aad3, < 33db24ad811b3576a0c2f8862506763f2be925b0 | ≥ ab7ac4eb9832e32a09f4e8042705484d2fb0aad3, < 97275339c34cfbccd65e87bc38fd910ae66c48ba | ≥ ab7ac4eb9832e32a09f4e8042705484d2fb0aad3, < 16989de75497574b5fafd174c0c233d5a86858b7 | ≥ ab7ac4eb9832e32a09f4e8042705484d2fb0aad3, < af8085e0fc3207ecbf8b9e7a635c790e36d058c6 | ≥ ab7ac4eb9832e32a09f4e8042705484d2fb0aad3, < c821a88bd720b0046433173185fd841a100d44ad | 4.6
3 vendors · 125 products
