Bug 2468183 (CVE-2026-43415)

Summary:	CVE-2026-43415 kernel: scsi: ufs: core: Fix SError in ufshcd_rtc_work() during UFS suspend
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	rhel-process-autobot, 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 Universal Flash Storage (UFS) host controller driver (scsi: ufs: core). A race condition exists during the UFS suspend process, where a timing issue can cause critical operations to execute out of sequence. This can lead to an Asynchronous SError Interrupt and a kernel panic, resulting in a Denial of Service (DoS).	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 2026-05-08 15:03:30 UTC

In the Linux kernel, the following vulnerability has been resolved:

scsi: ufs: core: Fix SError in ufshcd_rtc_work() during UFS suspend

In __ufshcd_wl_suspend(), cancel_delayed_work_sync() is called to cancel
the UFS RTC work, but it is placed after ufshcd_vops_suspend(hba, pm_op,
POST_CHANGE). This creates a race condition where ufshcd_rtc_work() can
still be running while ufshcd_vops_suspend() is executing. When
UFSHCD_CAP_CLK_GATING is not supported, the condition
!hba->clk_gating.active_reqs is always true, causing ufshcd_update_rtc()
to be executed. Since ufshcd_vops_suspend() typically performs clock
gating operations, executing ufshcd_update_rtc() at that moment triggers
an SError. The kernel panic trace is as follows:

Kernel panic - not syncing: Asynchronous SError Interrupt
Call trace:
 dump_backtrace+0xec/0x128
 show_stack+0x18/0x28
 dump_stack_lvl+0x40/0xa0
 dump_stack+0x18/0x24
 panic+0x148/0x374
 nmi_panic+0x3c/0x8c
 arm64_serror_panic+0x64/0x8c
 do_serror+0xc4/0xc8
 el1h_64_error_handler+0x34/0x4c
 el1h_64_error+0x68/0x6c
 el1_interrupt+0x20/0x58
 el1h_64_irq_handler+0x18/0x24
 el1h_64_irq+0x68/0x6c
 ktime_get+0xc4/0x12c
 ufshcd_mcq_sq_stop+0x4c/0xec
 ufshcd_mcq_sq_cleanup+0x64/0x1dc
 ufshcd_clear_cmd+0x38/0x134
 ufshcd_issue_dev_cmd+0x298/0x4d0
 ufshcd_exec_dev_cmd+0x1a4/0x1c4
 ufshcd_query_attr+0xbc/0x19c
 ufshcd_rtc_work+0x10c/0x1c8
 process_scheduled_works+0x1c4/0x45c
 worker_thread+0x32c/0x3e8
 kthread+0x120/0x1d8
 ret_from_fork+0x10/0x20

Fix this by moving cancel_delayed_work_sync() before the call to
ufshcd_vops_suspend(hba, pm_op, PRE_CHANGE), ensuring the UFS RTC work is
fully completed or cancelled at that point.

Comment 1 Keith Grant 2026-05-08 22:51:16 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026050845-CVE-2026-43415-bc74@gregkh/T