cbcvebase.
CVE-2026-23380
published 2026-03-25

CVE-2026-23380: In the Linux kernel, the following vulnerability has been resolved: tracing: Fix WARN_ON in tracing_buffers_mmap_close When a process forks, the child process…

PriorityP419medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.11%
1.7th percentile
In the Linux kernel, the following vulnerability has been resolved: tracing: Fix WARN_ON in tracing_buffers_mmap_close When a process forks, the child process copies the parent's VMAs but the user_mapped reference count is not incremented. As a result, when both the parent and child processes exit, tracing_buffers_mmap_close() is called twice. On the second call, user_mapped is already 0, causing the function to return -ENODEV and triggering a WARN_ON. Normally, this isn't an issue as the memory is mapped with VM_DONTCOPY set. But this is only a hint, and the application can call madvise(MADVISE_DOFORK) which resets the VM_DONTCOPY flag. When the application does that, it can trigger this issue on fork. Fix it by incrementing the user_mapped reference count without re-mapping the pages in the VMA's open callback.

Affected

15 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.19.8-1 (forky)linux 6.19.8-1 (forky)
linuxlinux
linuxlinux>= cf9f0f7c4c5bb45e7bb270e48bab6f7837825a64 < 91f3e8d84c89918769e71393f839c9fefadc258091f3e8d84c89918769e71393f839c9fefadc2580
linuxlinux>= cf9f0f7c4c5bb45e7bb270e48bab6f7837825a64 < cdd96641b64297a2db42676f051362b76280a58bcdd96641b64297a2db42676f051362b76280a58b
linuxlinux>= cf9f0f7c4c5bb45e7bb270e48bab6f7837825a64 < b0f269ba6fefe9e3cb9feedcf78fcd0b633800c0b0f269ba6fefe9e3cb9feedcf78fcd0b633800c0
linuxlinux>= cf9f0f7c4c5bb45e7bb270e48bab6f7837825a64 < e39bb9e02b68942f8e9359d2a3efe7d37ae6be0ee39bb9e02b68942f8e9359d2a3efe7d37ae6be0e
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel>= 0 < 6.19.8-16.19.8-1
linuxlinux_kernel>= 6.10.0 < 6.12.776.12.77
linuxlinux_kernel>= 6.10.1 < 6.12.776.12.77
linuxlinux_kernel>= 6.13 < 6.18.176.18.17
linuxlinux_kernel>= 6.13.0 < 6.18.176.18.17
linuxlinux_kernel>= 6.19 < 6.19.76.19.7
linuxlinux_kernel>= 6.19.0 < 6.19.76.19.7

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
vendor_redhat3.3LOW
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