cbcvebase.
CVE-2025-37878
published 2025-05-09

CVE-2025-37878: In the Linux kernel, the following vulnerability has been resolved: perf/core: Fix WARN_ON(!ctx) in __free_event() for partial init Move the get_ctx(child_ctx)…

PriorityP420medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.24%
15.2th percentile
In the Linux kernel, the following vulnerability has been resolved: perf/core: Fix WARN_ON(!ctx) in __free_event() for partial init Move the get_ctx(child_ctx) call and the child_event->ctx assignment to occur immediately after the child event is allocated. Ensure that child_event->ctx is non-NULL before any subsequent error path within inherit_event calls free_event(), satisfying the assumptions of the cleanup code. Details: There's no clear Fixes tag, because this bug is a side-effect of multiple interacting commits over time (up to 15 years old), not a single regression. The code initially incremented refcount then assigned context immediately after the child_event was created. Later, an early validity check for child_event was added before the refcount/assignment. Even later, a WARN_ON_ONCE() cleanup check was added, assuming event->ctx is valid if the pmu_ctx is valid. The problem is that the WARN_ON_ONCE() could trigger after the initial check passed but before child_event->ctx was assigned, violating its precondition. The solution is to assign child_event->ctx right after its initial validation. This ensures the context exists for any subsequent checks or cleanup routines, resolving the WARN_ON_ONCE(). To resolve it, defer the refcount update and child_event->ctx assignment directly after child_event->pmu_ctx is set but before checking if the parent event is orphaned. The cleanup routine depends on event->pmu_ctx being non-NULL before it verifies event->ctx is non-NULL. This also maintains the author's original intent of passing in child_ctx to find_get_pmu_context before its refcount/assignment. [ mingo: Expanded the changelog from another email by Gabriel Shahrouzi. ]

Affected

30 ranges· showing 25
VendorProductVersion rangeFixed in
debianlinux< linux 6.12.27-1 (forky)linux 6.12.27-1 (forky)
linuxlinux
linuxlinux>= 1209b0b29fd472e7dbd2b06544b019dd9f9b7e51 < cb56cd11feabf99e08bc18960700a53322ffcea7cb56cd11feabf99e08bc18960700a53322ffcea7
linuxlinux>= 6.12.24 < 6.12.266.12.26
linuxlinux>= 6.13.12 < 6.146.14
linuxlinux>= 6.14.3 < 6.14.56.14.5
linuxlinux>= 7ef5aa081f989ecfecc1df02068a80aebbd3ec31 < 90dc6c1e3b200812da8d0aa030e1b7fda8226d0e90dc6c1e3b200812da8d0aa030e1b7fda8226d0e
linuxlinux>= c70ca298036c58a88686ff388d3d367e9d21acf0 < 0ba3a4ab76fd3367b9cb680cad70182c896c795c0ba3a4ab76fd3367b9cb680cad70182c896c795c
linuxlinux_kernel< 6.6.896.6.89
linuxlinux_kernel
linuxlinux_kernel>= 0 < 6.12.27-16.12.27-1
linuxlinux_kernel>= 0 < 6.12.27-16.12.27-1
linuxlinux_kernel>= 0 < 6.8.0-100.1006.8.0-100.100
linuxlinux_kernel>= 0 < 6.14.0-22.226.14.0-22.22
linuxlinux_kernel>= 6.13 < 6.14.56.14.5
linuxlinux_kernel>= 6.7 < 6.12.266.12.26
msrcazl3_kernel_6.6.85.1-4_on_azure_linux_3.0
msrcazl3_kernel_6.6.92.2-1_on_azure_linux_3.0
msrccbl2_kernel_5.15.186.1-1_on_cbl_mariner_2.0
msrccbl2_kernel_5.15.200.1-1_on_cbl_mariner_2.0
msrccbl2_kernel_5.15.202.1-1_on_cbl_mariner_2.0
ubuntulinux-aws
ubuntulinux-aws-6.8
ubuntulinux-gkeop
ubuntulinux-nvidia

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv5.5MEDIUM
vendor_debian5.5LOW
vendor_msrc5.5MEDIUM
vendor_redhat5.5MEDIUM
vendor_ubuntu3.2LOW
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