CVE-2026-93057 scsi: ufs: core: Avoid possible memory reclaim deadlock in TX EQTR context
A deadlock in the Linux kernel UFS driver can cause a denial of service when memory allocation triggers reclaim during quiesced I/O.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-93057?
CVE-2026-93057 is a denial of service vulnerability in Linux, published on 17 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
scsi: ufs: core: Avoid possible memory reclaim deadlock in TX EQTR context
TX EQTR may run while devfreq gear scaling has quiesced the UFS tagset. In that context, functions ufshcd_tx_eqtr(), __ufshcd_tx_eqtr() and ufs_qcom_get_rx_fom() allocate memory with GFP_KERNEL. If direct reclaim is triggered, reclaim/writeback can depend on I/O to UFS device. Because the queue is quiesced, this can cause deadlock.
Use memalloc_noio_save/restore() in ufshcd_tx_eqtr() to cover all allocations in the TX EQTR call tree, including:
- params->eqtr_record in ufshcd_tx_eqtr()
- eqtr_data in __ufshcd_tx_eqtr()
- params in ufs_qcom_get_rx_fom()
This is preferred over tagging individual call sites with GFP_NOIO, as it automatically covers any future allocations added anywhere in the call tree without requiring each caller to be aware of this constraint.
[mkp: fix label as suggested by Bart]
Which versions are affected by CVE-2026-93057?
How do I fix CVE-2026-93057?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-93057 being exploited?
There is no known exploitation of CVE-2026-93057 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-93057, GHSA-2rmf-84jj-472q, UBUNTU-CVE-2026-93057.