ghsa-frjr-3w6j-qh2v
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
RDMA/cma: Fix workqueue crash in cma_netevent_work_handler
struct rdma_cm_id has member "struct work_struct net_work" that is reused for enqueuing cma_netevent_work_handler()s onto cma_wq.
Below crash[1] can occur if more than one call to cma_netevent_callback() occurs in quick succession, which further enqueues cma_netevent_work_handler()s for the same rdma_cm_id, overwriting any previously queued work-item(s) that was just scheduled to run i.e. there is no guarantee the queued work item may run between two successive calls to cma_netevent_callback() and the 2nd INIT_WORK would overwrite the 1st work item (for the same rdma_cm_id), despite grabbing id_table_lock during enqueue.
Also drgn analysis [2] indicates the work item was likely overwritten.
Fix this by moving the INIT_WORK() to __rdma_create_id(), so that it doesn't race with any existing queue_work() or its worker thread.
[1] Trimmed crash stack:
BUG: kernel NULL pointer dereference, address: 0000000000000008 kworker/u256:6 ... 6.12.0-0... Workqueue: cma_netevent_work_handler [rdma_cm] (rdma_cm) RIP: 0010:process_one_work+0xba/0x31a Call Trace: worker_thread+0x266/0x3a0 kthread+0xcf/0x100 ret_from_fork+0x31/0x50 ret_from_fork_asm+0x1a/0x30 =============================================
[2] drgn crash analysis:
trace = prog.crashed_thread().stack_trace() trace (0) crash_setup_regs (./arch/x86/include/asm/kexec.h:111:15) (1) __crash_kexec (kernel/crash_core.c:122:4) (2) panic (kernel/panic.c:399:3) (3) oops_end (arch/x86/kernel/dumpstack.c:382:3) ... (8) process_one_work (kernel/workqueue.c:3168:2) (9) process_scheduled_works (kernel/workqueue.c:3310:3) (10) worker_thread (kernel/workqueue.c:3391:4) (11) kthread (kernel/kthread.c:389:9)
Line workqueue.c:3168 for this kernel version is in process_one_work(): 3168 strscpy(worker->desc, pwq->wq->name, WORKER_DESC_LEN);
trace[8]["work"] (struct work_struct )0xffff92577d0a21d8 = { .data = (atomic_long_t){ .counter = (s64)536870912, <=== Note }, .entry = (struct list_head){ .next = (struct list_head )0xffff924d075924c0, .prev = (struct list_head )0xffff924d075924c0, }, .func = (work_func_t)cma_netevent_work_handler+0x0 = 0xffffffffc2cec280, }
Suspicion is that pwq is NULL:
trace[8]["pwq"] (struct pool_workqueue *)
In process_one_work(), pwq is assigned from: struct pool_workqueue *pwq = get_work_pwq(work);
and get_work_pwq() is: static struct pool_workqueue get_work_pwq(struct work_struct work) { unsigned long data = atomic_long_read(&work->data);
if (data & WORK_STRUCT_PWQ)
return work_struct_pwq(data);
else
return NULL;
}
WORK_STRUCT_PWQ is 0x4:
print(repr(prog['WORK_STRUCT_PWQ'])) Object(prog, 'enum work_flags', value=4)
But work->data is 536870912 which is 0x20000000. So, get_work_pwq() returns NULL and we crash in process_one_work(): 3168 strscpy(worker->desc, pwq->wq->name, WORKER_DESC_LEN); =============================================
{
"affected": [],
"aliases": [
"CVE-2025-37772"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-05-01T14:15:40Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/cma: Fix workqueue crash in cma_netevent_work_handler\n\nstruct rdma_cm_id has member \"struct work_struct net_work\"\nthat is reused for enqueuing cma_netevent_work_handler()s\nonto cma_wq.\n\nBelow crash[1] can occur if more than one call to\ncma_netevent_callback() occurs in quick succession,\nwhich further enqueues cma_netevent_work_handler()s for the\nsame rdma_cm_id, overwriting any previously queued work-item(s)\nthat was just scheduled to run i.e. there is no guarantee\nthe queued work item may run between two successive calls\nto cma_netevent_callback() and the 2nd INIT_WORK would overwrite\nthe 1st work item (for the same rdma_cm_id), despite grabbing\nid_table_lock during enqueue.\n\nAlso drgn analysis [2] indicates the work item was likely overwritten.\n\nFix this by moving the INIT_WORK() to __rdma_create_id(),\nso that it doesn\u0027t race with any existing queue_work() or\nits worker thread.\n\n[1] Trimmed crash stack:\n=============================================\nBUG: kernel NULL pointer dereference, address: 0000000000000008\nkworker/u256:6 ... 6.12.0-0...\nWorkqueue: cma_netevent_work_handler [rdma_cm] (rdma_cm)\nRIP: 0010:process_one_work+0xba/0x31a\nCall Trace:\n worker_thread+0x266/0x3a0\n kthread+0xcf/0x100\n ret_from_fork+0x31/0x50\n ret_from_fork_asm+0x1a/0x30\n=============================================\n\n[2] drgn crash analysis:\n\n\u003e\u003e\u003e trace = prog.crashed_thread().stack_trace()\n\u003e\u003e\u003e trace\n(0) crash_setup_regs (./arch/x86/include/asm/kexec.h:111:15)\n(1) __crash_kexec (kernel/crash_core.c:122:4)\n(2) panic (kernel/panic.c:399:3)\n(3) oops_end (arch/x86/kernel/dumpstack.c:382:3)\n...\n(8) process_one_work (kernel/workqueue.c:3168:2)\n(9) process_scheduled_works (kernel/workqueue.c:3310:3)\n(10) worker_thread (kernel/workqueue.c:3391:4)\n(11) kthread (kernel/kthread.c:389:9)\n\nLine workqueue.c:3168 for this kernel version is in process_one_work():\n3168\tstrscpy(worker-\u003edesc, pwq-\u003ewq-\u003ename, WORKER_DESC_LEN);\n\n\u003e\u003e\u003e trace[8][\"work\"]\n*(struct work_struct *)0xffff92577d0a21d8 = {\n\t.data = (atomic_long_t){\n\t\t.counter = (s64)536870912, \u003c=== Note\n\t},\n\t.entry = (struct list_head){\n\t\t.next = (struct list_head *)0xffff924d075924c0,\n\t\t.prev = (struct list_head *)0xffff924d075924c0,\n\t},\n\t.func = (work_func_t)cma_netevent_work_handler+0x0 = 0xffffffffc2cec280,\n}\n\nSuspicion is that pwq is NULL:\n\u003e\u003e\u003e trace[8][\"pwq\"]\n(struct pool_workqueue *)\u003cabsent\u003e\n\nIn process_one_work(), pwq is assigned from:\nstruct pool_workqueue *pwq = get_work_pwq(work);\n\nand get_work_pwq() is:\nstatic struct pool_workqueue *get_work_pwq(struct work_struct *work)\n{\n \tunsigned long data = atomic_long_read(\u0026work-\u003edata);\n\n \tif (data \u0026 WORK_STRUCT_PWQ)\n \t\treturn work_struct_pwq(data);\n \telse\n \t\treturn NULL;\n}\n\nWORK_STRUCT_PWQ is 0x4:\n\u003e\u003e\u003e print(repr(prog[\u0027WORK_STRUCT_PWQ\u0027]))\nObject(prog, \u0027enum work_flags\u0027, value=4)\n\nBut work-\u003edata is 536870912 which is 0x20000000.\nSo, get_work_pwq() returns NULL and we crash in process_one_work():\n3168\tstrscpy(worker-\u003edesc, pwq-\u003ewq-\u003ename, WORKER_DESC_LEN);\n=============================================",
"id": "GHSA-frjr-3w6j-qh2v",
"modified": "2025-05-01T15:31:44Z",
"published": "2025-05-01T15:31:44Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-37772"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/45f5dcdd049719fb999393b30679605f16ebce14"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/51003b2c872c63d28bcf5fbcc52cf7b05615f7b7"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/b172a4a0de254f1fcce7591833a9a63547c2f447"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/c2b169fc7a12665d8a675c1ff14bca1b9c63fb9a"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d23fd7a539ac078df119707110686a5b226ee3bb"
}
],
"schema_version": "1.4.0",
"severity": []
}
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- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.