GHSA-X48Q-47QQ-GV8G
Vulnerability from github – Published: 2026-06-24 09:30 – Updated: 2026-06-24 09:30In the Linux kernel, the following vulnerability has been resolved:
net/smc: avoid NULL deref of conn->lnk in smc_msg_event tracepoint
The smc_msg_event tracepoint class, shared by smc_tx_sendmsg and smc_rx_recvmsg, unconditionally dereferences smc->conn.lnk:
__string(name, smc->conn.lnk->ibname)
conn->lnk is only set for SMC-R; for SMC-D it is NULL. Other code on these paths already handles this (e.g. !conn->lnk in SMC_STAT_RMB_TX_SIZE_SMALL()). With the tracepoint enabled, the first sendmsg()/recvmsg() on an SMC-D socket crashes:
Oops: general protection fault, probably for non-canonical address KASAN: null-ptr-deref in range [...] RIP: 0010:strlen+0x1e/0xa0 Call Trace: trace_event_raw_event_smc_msg_event (net/smc/smc_tracepoint.h:44) smc_rx_recvmsg (net/smc/smc_rx.c:515) smc_recvmsg (net/smc/af_smc.c:2859) __sys_recvfrom (net/socket.c:2315) __x64_sys_recvfrom (net/socket.c:2326) do_syscall_64
The faulting address 0x3e0 is offsetof(struct smc_link, ibname), confirming the NULL ->lnk deref. Enabling the tracepoint requires root, but the trigger itself is unprivileged: socket(AF_SMC, ...) has no capability check, and SMC-D negotiation needs no admin step on s390 or on x86 with the loopback ISM device loaded.
Log an empty device name for SMC-D instead of dereferencing NULL.
{
"affected": [],
"aliases": [
"CVE-2026-52941"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-06-24T08:16:24Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/smc: avoid NULL deref of conn-\u003elnk in smc_msg_event tracepoint\n\nThe smc_msg_event tracepoint class, shared by smc_tx_sendmsg and\nsmc_rx_recvmsg, unconditionally dereferences smc-\u003econn.lnk:\n\n\t__string(name, smc-\u003econn.lnk-\u003eibname)\n\nconn-\u003elnk is only set for SMC-R; for SMC-D it is NULL. Other code on\nthese paths already handles this (e.g. !conn-\u003elnk in\nSMC_STAT_RMB_TX_SIZE_SMALL()). With the tracepoint enabled, the first\nsendmsg()/recvmsg() on an SMC-D socket crashes:\n\n Oops: general protection fault, probably for non-canonical address\n KASAN: null-ptr-deref in range [...]\n RIP: 0010:strlen+0x1e/0xa0\n Call Trace:\n trace_event_raw_event_smc_msg_event (net/smc/smc_tracepoint.h:44)\n smc_rx_recvmsg (net/smc/smc_rx.c:515)\n smc_recvmsg (net/smc/af_smc.c:2859)\n __sys_recvfrom (net/socket.c:2315)\n __x64_sys_recvfrom (net/socket.c:2326)\n do_syscall_64\n\nThe faulting address 0x3e0 is offsetof(struct smc_link, ibname),\nconfirming the NULL -\u003elnk deref. Enabling the tracepoint requires\nroot, but the trigger itself is unprivileged: socket(AF_SMC, ...) has\nno capability check, and SMC-D negotiation needs no admin step on\ns390 or on x86 with the loopback ISM device loaded.\n\nLog an empty device name for SMC-D instead of dereferencing NULL.",
"id": "GHSA-x48q-47qq-gv8g",
"modified": "2026-06-24T09:30:49Z",
"published": "2026-06-24T09:30:49Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-52941"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/561cf66fa9b6c86dfe4e687d2d1aeaaa6739917f"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/68200112534bb2acd1d7117dc2d5c124868d866d"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/720c76b930c52cd58f50eb6b10569d03dccc7959"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/7bf563badd37cb796df5477d2b78bb64148a1268"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/b706d6d76a2a2793fe5ad0fbc2a75b6a460094ef"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d2ea0b8aef8746e147602eac87ca8538f4bc7e66"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
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