Bug 2536483 (CVE-2026-90417)

Summary: CVE-2026-90417 kernel: RDMA/cxgb4: Fix dereg_skb leak and double free in write_tpt_entry()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in the Linux kernel's RDMA/cxgb4 component. When the device enters a fatal error state or experiences an allocation failure within the `write_tpt_entry()` function, it can lead to a memory leak and a double free vulnerability. A local attacker could potentially exploit this issue to cause a denial of service or, in some scenarios, achieve arbitrary code execution.
 Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-09-17 18:10:19 UTC 
In the Linux kernel, the following vulnerability has been resolved:

RDMA/cxgb4: Fix dereg_skb leak and double free in write_tpt_entry()

When the device is in the fatal error state, write_tpt_entry() returns -EIO
before handing the caller's preallocated skb to the transmit path; its
allocation-failure returns do the same. c4iw_dereg_mr() ignores the error
and frees mhp, leaking mhp->dereg_skb. c4iw_get_dma_mr() instead frees the
skb a second time after dereg_mem() already consumed it, a double free.

Make write_tpt_entry() the sole owner of a non-NULL skb, freeing it on
every return preceding handoff to c4iw_ofld_send(): fatal error, tpt and
stag allocation failure. c4iw_ofld_send() consumes the skb on success and
error alike, so drop the redundant kfree_skb() in c4iw_get_dma_mr() after
dereg_mem().
Comment 1 gkamathe 2026-09-21 12:21:31 UTC 
Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-90417.mbox