CVE-2023-54237
Description
In the Linux kernel, the following vulnerability has been resolved:
net/smc: fix potential panic dues to unprotected smc_llc_srv_add_link()
There is a certain chance to trigger the following panic:
PID: 5900 TASK: ffff88c1c8af4100 CPU: 1 COMMAND: "kworker/1:48" #0 [ffff9456c1cc79a0] machine_kexec at ffffffff870665b7 #1 [ffff9456c1cc79f0] __crash_kexec at ffffffff871b4c7a #2 [ffff9456c1cc7ab0] crash_kexec at ffffffff871b5b60 #3 [ffff9456c1cc7ac0] oops_end at ffffffff87026ce7 #4 [ffff9456c1cc7ae0] page_fault_oops at ffffffff87075715 #5 [ffff9456c1cc7b58] exc_page_fault at ffffffff87ad0654 #6 [ffff9456c1cc7b80] asm_exc_page_fault at ffffffff87c00b62 [exception RIP: ib_alloc_mr+19] RIP: ffffffffc0c9cce3 RSP: ffff9456c1cc7c38 RFLAGS: 00010202 RAX: 0000000000000000 RBX: 0000000000000002 RCX: 0000000000000004 RDX: 0000000000000010 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88c1ea281d00 R8: 000000020a34ffff R9: ffff88c1350bbb20 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000010 R14: ffff88c1ab040a50 R15: ffff88c1ea281d00 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #7 [ffff9456c1cc7c60] smc_ib_get_memory_region at ffffffffc0aff6df [smc] #8 [ffff9456c1cc7c88] smcr_buf_map_link at ffffffffc0b0278c [smc] #9 [ffff9456c1cc7ce0] __smc_buf_create at ffffffffc0b03586 [smc]
The reason here is that when the server tries to create a second link, smc_llc_srv_add_link() has no protection and may add a new link to link group. This breaks the security environment protected by llc_conf_mutex.
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
A race condition in the Linux kernel's SMC protocol can cause a panic when creating a second link without proper locking.
Vulnerability
CVE-2023-54237 describes a race condition in the Linux kernel's SMC (Shared Memory Communications) protocol implementation. The function smc_llc_srv_add_link() lacks proper synchronization, allowing a new link to be added to a link group without holding the llc_conf_mutex. This breaks the mutual exclusion expected by other code paths, leading to a use-after-free or null-pointer dereference when the kernel subsequently attempts to allocate memory regions via ib_alloc_mr.
Exploitation
An attacker who can trigger the creation of a second SMC link on a server (e.g., by sending crafted network packets or exploiting a privileged position on the same host) can race window) can cause the kernel to crash. The attack requires the ability to influence link creation timing, but no special privileges beyond network access to the SMC endpoint. The race window is small but deterministic under load.
Impact
Successful exploitation results in a kernel panic (denial of service). The crash trace shows a page fault in ib_alloc_mr called from smc_ib_get_memory_region, confirming memory corruption. No privilege escalation is described; the impact is limited to system availability.
Mitigation
The fix is included in Linux kernel stable updates. Patches are available at the referenced commits [1][2]. Administrators should apply the latest kernel updates from their distribution. No workaround is documented; the vulnerability is fixed by adding proper locking around smc_llc_srv_add_link().
AI Insight generated on May 19, 2026. Synthesized from this CVE's description and the cited reference URLs; citations are validated against the source bundle.
Affected products
1Patches
3f2f46de98c110c764cc271d3e40b801b3603Vulnerability mechanics
Generated on May 9, 2026. Inputs: CWE entries + fix-commit diffs from this CVE's patches. Citations validated against bundle.
References
3News mentions
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