CVE-2023-53525: RDMA/cma: Allow UD qp_type to join multicast only
Vulnerability summary
CVE-2023-53525 is a medium (CVSS 5.5) Use of Uninitialized Resource vulnerability in linux. EPSS estimates a 0.15% chance of exploitation in the next 30 days, higher than 4% of scored vulnerabilities.
Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 6 · Related 4Timeline
- 01-10-2025PublishedVulnerability first disclosed.
- 23-05-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: RDMA/cma: Allow UD qp_type to join multicast only As for multicast: - The SIDR is the only mode that makes sense; - Besides PS_UDP, other port spaces like PS_IB is also allowed, as it is UD compatible. In this case qkey also needs to be set [1]. This patch allows only UD qp_type to join multicast, and set qkey to default if it's not set, to fix an uninit-value error: the ib->rec.qkey field is accessed without being initialized. ===================================================== BUG: KMSAN: uninit-value in cma_set_qkey drivers/infiniband/core/cma.c:510 [inline] BUG: KMSAN: uninit-value in cma_make_mc_event+0xb73/0xe00 drivers/infiniband/core/cma.c:4570 cma_set_qkey drivers/infiniband/core/cma.c:510 [inline] cma_make_mc_event+0xb73/0xe00 drivers/infiniband/core/cma.c:4570 cma_iboe_join_multicast drivers/infiniband/core/cma.c:4782 [inline] rdma_join_multicast+0x2b83/0x30a0 drivers/infiniband/core/cma.c:4814 ucma_process_join+0xa76/0xf60 drivers/infiniband/core/ucma.c:1479 ucma_join_multicast+0x1e3/0x250 drivers/infiniband/core/ucma.c:1546 ucma_write+0x639/0x6d0 drivers/infiniband/core/ucma.c:1732 vfs_write+0x8ce/0x2030 fs/read_write.c:588 ksys_write+0x28c/0x520 fs/read_write.c:643 __do_sys_write fs/read_write.c:655 [inline] __se_sys_write fs/read_write.c:652 [inline] __ia32_sys_write+0xdb/0x120 fs/read_write.c:652 do_syscall_32_irqs_on arch/x86/entry/common.c:114 [inline] __do_fast_syscall_32+0x96/0xf0 arch/x86/entry/common.c:180 do_fast_syscall_32+0x34/0x70 arch/x86/entry/common.c:205 do_SYSENTER_32+0x1b/0x20 arch/x86/entry/common.c:248 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c Local variable ib.i created at: cma_iboe_join_multicast drivers/infiniband/core/cma.c:4737 [inline] rdma_join_multicast+0x586/0x30a0 drivers/infiniband/core/cma.c:4814 ucma_process_join+0xa76/0xf60 drivers/infiniband/core/ucma.c:1479 CPU: 0 PID: 29874 Comm: syz-executor.3 Not tainted 5.16.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ===================================================== [1] https://lore.kernel.org/linux-rdma/20220117183832.GD84788@nvidia.com/
CVSS metrics
4 scores · 3 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.15%
Chance of exploitation in the next 30 days
Percentile
4%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.14% on 04-10-2026
Known exploited
Compare KEV catalogsNot in the CISA KEV catalog.
Not in the ENISA CNW catalog.
Not in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu108 products
- linux< 5.15.0-79.86
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws< 5.15.0-1042.47
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ b5de0c60cc30c2a3513c7188c73f3f29acc29234, < ae11498851423d6de27aebfe12a5ee85060ab1d5 | ≥ b5de0c60cc30c2a3513c7188c73f3f29acc29234, < 48e8e7851dc0b1584d83817a78fc7108c8904b54 | ≥ b5de0c60cc30c2a3513c7188c73f3f29acc29234, < 02eabb635bc64bd1e3a7cf887d6d182bffb64b99 | ≥ b5de0c60cc30c2a3513c7188c73f3f29acc29234, < bb18b9dbac2bbdf7695e0bfaac4bf944ff7b207d | ≥ b5de0c60cc30c2a3513c7188c73f3f29acc29234, < 58e84f6b3e84e46524b7e5a916b53c1ad798bc8f | b8d1adbff983be0b54f61c9a4169609d7fab0620 | feed39c8d1282279fcb30612aa0e8d2635c11280 | ≥ 5.8.17, < 5.9 | ≥ 5.9.2, < 5.10 | 5.10
- linux_kernel≥ 5.8.17, < 5.9 | ≥ 5.9.2, < 5.10.178 | ≥ 5.11, < 5.15.108 | ≥ 5.16, < 6.1.25 | ≥ 6.2, < 6.2.12 | 6.3:rc1 | 6.3:rc2 | 6.3:rc3 | 6.3:rc4 | 6.3:rc5 | 6.3:rc6
Debian1 product
- linux< 6.1.25-1
3 vendors · 111 products