Bug 2502342 (CVE-2026-63967)

Summary: CVE-2026-63967 kernel: iio: imu: st_lsm6dsx: fix stack leak in tagged FIFO buffer
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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Doc Text:
A flaw was found in the Linux kernel's `st_lsm6dsx` driver. This vulnerability occurs in the tagged FIFO (First-In, First-Out) buffer path, where a buffer on the stack is not properly initialized. A local attacker could exploit this by reading uninitialized memory from the kernel stack, leading to information disclosure.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-07-19 16:02:55 UTC
In the Linux kernel, the following vulnerability has been resolved:

iio: imu: st_lsm6dsx: fix stack leak in tagged FIFO buffer

The tagged FIFO path declares iio_buff on the stack with __aligned(8)
but no initializer, but there is a hole in the structure, which will
then leak to userspace as ST_LSM6DSX_SAMPLE_SIZE bytes (6) will be
copied, but the space between that and the timestamp are not
initialized.

Commit c14edb4d0bdc ("iio:imu:st_lsm6dsx Fix alignment and data leak
issues") moved the untagged FIFO path to a kzalloc'd buffer in hw->scan,
but for the tagged path it only added the alignment qualifier and not
the initializer :(

Fix this by just zero-initializing the structure on the stack.