CVE-2026-45856RDMA/uverbs: Validate wqe_size before using it in ib_uverbs_post_send
Updated under an hour ago ()
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In the Linux kernel, the following vulnerability has been resolved: RDMA/uverbs: Validate wqe_size before using it in ib_uverbs_post_send ib_uverbs_post_send() uses cmd.wqe_size from userspace without any validation before passing it to kmalloc() and using the allocated buffer as struct ib_uverbs_send_wr. If a user provides a small wqe_size value (e.g., 1), kmalloc() will succeed, but subsequent accesses to user_wr->opcode, user_wr->num_sge, and other fields will read beyond the allocated buffer, resulting in an out-of-bounds read from kernel heap memory. This could potentially leak sensitive kernel information to userspace. Additionally, providing an excessively large wqe_size can trigger a WARNING in the memory allocation path, as reported by syzkaller. This is inconsistent with ib_uverbs_unmarshall_recv() which properly validates that wqe_size >= sizeof(struct ib_uverbs_recv_wr) before proceeding. Add the same validation for ib_uverbs_post_send() to ensure wqe_size is at least sizeof(struct ib_uverbs_send_wr).
- CVSS
- 7.1 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/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
- Analyzed
- Record last updated
- Oct 16, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | from c3bea3d2dc5358e05541527283279102383b0231 before 9c15ec4cd4e7f57c6bbcb4e73e99290f150dd2a7; from c3bea3d2dc5358e05541527283279102383b0231 before 9b5ac1c15334d46c0dbd49d64a2257b929500163; from c3bea3d2dc5358e05541527283279102383b0231 before 01c9b152647dc70dc06a4a2eff86ebb3b3c76075; from c3bea3d2dc5358e05541527283279102383b0231 before bf1feed1a7886af945f92890493aefd2b5c9928a; from c3bea3d2dc5358e05541527283279102383b0231 before d533425ac1f2925b4fc3e4ed9b9d72362cb23475; from c3bea3d2dc5358e05541527283279102383b0231 before bf4454da8b1e712714628c0a0d6e7845bb40790a; from c3bea3d2dc5358e05541527283279102383b0231 before bef70ff9841990658610512b4a18e4a88c9b4df6; from c3bea3d2dc5358e05541527283279102383b0231 before 1956f0a74ccf5dc9c3ef717f2985c3ed3400aab0 | CNA record |
linux linux_kernel linux:linux_kernel | from 5.0 before 5.10.252; from 5.11 before 5.15.202; from 5.16 before 6.1.165; from 6.2 before 6.6.128; from 6.7 before 6.12.75; from 6.13 before 6.18.14; from 6.19 before 6.19.4 | NVD |
References
- https://git.kernel.org/stable/c/9c15ec4cd4e7f57c6bbcb4e73e99290f150dd2a7patch
- https://git.kernel.org/stable/c/9b5ac1c15334d46c0dbd49d64a2257b929500163patch
- https://git.kernel.org/stable/c/01c9b152647dc70dc06a4a2eff86ebb3b3c76075patch
- https://git.kernel.org/stable/c/bf1feed1a7886af945f92890493aefd2b5c9928apatch
- https://git.kernel.org/stable/c/d533425ac1f2925b4fc3e4ed9b9d72362cb23475patch
- https://git.kernel.org/stable/c/bf4454da8b1e712714628c0a0d6e7845bb40790apatch
- https://git.kernel.org/stable/c/bef70ff9841990658610512b4a18e4a88c9b4df6patch
- https://git.kernel.org/stable/c/1956f0a74ccf5dc9c3ef717f2985c3ed3400aab0patch
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.