CVE-2026-89508RDMA/ucma: Lock the handler in ucma_set_ib_path()
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No exploitation reported and no EPSS estimate yet.
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In the Linux kernel, the following vulnerability has been resolved: RDMA/ucma: Lock the handler in ucma_set_ib_path() ucma_set_ib_path() calls ucma_event_handler() straight from the write() path, without the handler lock that keeps ctx->file stable while a uevent is queued. The handler re-reads ctx->file for every dereference: mutex_lock(&ctx->file->mut); /* file A */ list_add_tail(&uevent->list, &ctx->file->event_list); /* file B */ mutex_unlock(&ctx->file->mut); /* file B */ wake_up_interruptible(&ctx->file->poll_wait); /* file B */ A concurrent ucma_migrate_id() reassigns ctx->file while the SET_OPTION caller sleeps in mutex_lock(), so the list_add_tail() lands on file B's event_list while only file A's mutex is held, racing every other user of that list: BUG: KASAN: slab-use-after-free in __list_add_valid_or_report+0x1aa/0x1c0 Read of size 8 at addr ffff888153c6a418 by task poc_corr/486 Call Trace: __list_add_valid_or_report+0x1aa/0x1c0 ucma_event_handler+0x1be/0xc00 ucma_set_ib_path+0x45e/0x710 ucma_set_option+0x32e/0x590 ucma_write+0x1f9/0x330 Allocated by task 505: ucma_write_cm_event+0x1a1/0x660 Freed by task 505: kfree+0x1da/0x4c0 ucma_get_event+0x5d5/0x7e0 The freed object is a ucma_event that another thread dequeued from file B's list under file B's mutex. File A's mut is left held on top of that, wedging its next writer in uninterruptible sleep. This path needs a bound and address-resolved cm_id, so it requires an RDMA device to be present. Take the handler lock around the call.
- CVSS
- 7.8 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Received
- Record last updated
- Sep 14, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | 09e328e47a695b0d346598f5d6593ee598e64885 builds before 3dd07b369371a2f29e1c3caf1ade85bb92b4c551; from 09e328e47a695b0d346598f5d6593ee598e64885 before b2da0d488a1c72956ebb0a57015ee8ee6a2f7748; from 09e328e47a695b0d346598f5d6593ee598e64885 before a7f8d26e653ee43b0b572984b8ec544d3b3b6f3c; from 09e328e47a695b0d346598f5d6593ee598e64885 before 71dc206f2e2a645dac78879768762451aa1799f7; from 09e328e47a695b0d346598f5d6593ee598e64885 before 764586f8f6180084c5a7d622120f526acc6ce0c9; from 09e328e47a695b0d346598f5d6593ee598e64885 before 28ac2dd416482d1c763c4af5d61af465b387fb50; from 09e328e47a695b0d346598f5d6593ee598e64885 before 43a7d8ae9f645dc00235cfa4bf57673c20b769f8; from 09e328e47a695b0d346598f5d6593ee598e64885 before ecbe7d36dc2de07e5dfbb4a8ff5b315ab43de820 | CNA record |
References
- https://git.kernel.org/stable/c/3dd07b369371a2f29e1c3caf1ade85bb92b4c551
- https://git.kernel.org/stable/c/b2da0d488a1c72956ebb0a57015ee8ee6a2f7748
- https://git.kernel.org/stable/c/a7f8d26e653ee43b0b572984b8ec544d3b3b6f3c
- https://git.kernel.org/stable/c/71dc206f2e2a645dac78879768762451aa1799f7
- https://git.kernel.org/stable/c/764586f8f6180084c5a7d622120f526acc6ce0c9
- https://git.kernel.org/stable/c/28ac2dd416482d1c763c4af5d61af465b387fb50
- https://git.kernel.org/stable/c/43a7d8ae9f645dc00235cfa4bf57673c20b769f8
- https://git.kernel.org/stable/c/ecbe7d36dc2de07e5dfbb4a8ff5b315ab43de820
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.