Bug 2546451 (CVE-2026-98208)

Summary: CVE-2026-98208 kernel: mmc: sdio_uart: fix xmit_fifo leak when the port table is full
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: low Docs Contact:
Priority: low    
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   
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Doc Text:
A flaw was found in the Linux kernel's SDIO UART driver. When registering a new device port while all available port slots are occupied, the driver fails to release an allocated transmit buffer during error handling. A local user could exploit this flaw by repeatedly triggering failed device attachments, resulting in a memory leak and a potential Denial of Service (DoS) due to memory exhaustion.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description OSIDB Bzimport 2026-10-06 09:22:42 UTC 
In the Linux kernel, the following vulnerability has been resolved:

mmc: sdio_uart: fix xmit_fifo leak when the port table is full

sdio_uart_add_port() allocates the transmit fifo before claiming a
slot in sdio_uart_table[].  When all UART_NR slots are taken, it
returns -EBUSY with the fifo still allocated, but the probe error
path only kfree()s the port, leaking the transmit fifo.

Free the fifo in the failure path of sdio_uart_add_port() itself so
the function retains nothing on error.
Comment 1 Mauro Matteo Cascella 2026-10-09 08:53:50 UTC 
Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98208.mbox