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CVE-2025-38563
published 2025-08-19

CVE-2025-38563: In the Linux kernel, the following vulnerability has been resolved: perf/core: Prevent VMA split of buffer mappings The perf mmap code is careful about…

high7.8CVSS 3.1
AVLACLPRLUINSUCHIHAH
In the Linux kernel, the following vulnerability has been resolved: perf/core: Prevent VMA split of buffer mappings The perf mmap code is careful about mmap()'ing the user page with the ringbuffer and additionally the auxiliary buffer, when the event supports it. Once the first mapping is established, subsequent mapping have to use the same offset and the same size in both cases. The reference counting for the ringbuffer and the auxiliary buffer depends on this being correct. Though perf does not prevent that a related mapping is split via mmap(2), munmap(2) or mremap(2). A split of a VMA results in perf_mmap_open() calls, which take reference counts, but then the subsequent perf_mmap_close() calls are not longer fulfilling the offset and size checks. This leads to reference count leaks. As perf already has the requirement for subsequent mappings to match the initial mapping, the obvious consequence is that VMA splits, caused by resizing of a mapping or partial unmapping, have to be prevented. Implement the vm_operations_struct::may_split() callback and return unconditionally -EINVAL. That ensures that the mapping offsets and sizes cannot be changed after the fact. Remapping to a different fixed address with the same size is still possible as it takes the references for the new mapping and drops those of the old mapping.

Affected

29 ranges· showing 25
VendorProductVersion rangeFixed in
debiandebian_linux
debianlinux< linux 6.1.148-1 (bookworm)linux 6.1.148-1 (bookworm)
debianlinux-6.1< linux 6.1.148-1 (bookworm)linux 6.1.148-1 (bookworm)
linuxlinux
linuxlinux>= 45bfb2e50471abbbfd83d40d28c986078b0d24ff < e4346ffec2c44d6b0be834d59b20632b5bb5729ee4346ffec2c44d6b0be834d59b20632b5bb5729e
linuxlinux>= 45bfb2e50471abbbfd83d40d28c986078b0d24ff < d52451a9210f2e5a079ba052918c93563518a9ffd52451a9210f2e5a079ba052918c93563518a9ff
linuxlinux>= 45bfb2e50471abbbfd83d40d28c986078b0d24ff < 3bd518cc7ea61076bcd725e36ff0e690754977c03bd518cc7ea61076bcd725e36ff0e690754977c0
linuxlinux>= 45bfb2e50471abbbfd83d40d28c986078b0d24ff < 7b84cb58d1f0aa07656802eae24689566e5f5b1b7b84cb58d1f0aa07656802eae24689566e5f5b1b
linuxlinux>= 45bfb2e50471abbbfd83d40d28c986078b0d24ff < 6757a31a8e295ae4f01717a954afda173f25a1216757a31a8e295ae4f01717a954afda173f25a121
linuxlinux>= 45bfb2e50471abbbfd83d40d28c986078b0d24ff < e529888b7e8092912dd8789bdfc76685ccd2ff5fe529888b7e8092912dd8789bdfc76685ccd2ff5f
linuxlinux>= 45bfb2e50471abbbfd83d40d28c986078b0d24ff < ff668930871e0198c7f4e325058b8b7c286787bdff668930871e0198c7f4e325058b8b7c286787bd
linuxlinux>= 45bfb2e50471abbbfd83d40d28c986078b0d24ff < 65311aad4c808bedad0c05d9bb8b06c47dae73eb65311aad4c808bedad0c05d9bb8b06c47dae73eb
linuxlinux>= 45bfb2e50471abbbfd83d40d28c986078b0d24ff < b024d7b56c77191cde544f838debb7f8451cd0d6b024d7b56c77191cde544f838debb7f8451cd0d6
linuxlinux_kernel>= 0 < 5.10.244-15.10.244-1
linuxlinux_kernel>= 0 < 6.1.148-16.1.148-1
linuxlinux_kernel>= 0 < 6.12.43-16.12.43-1
linuxlinux_kernel>= 0 < 6.16.3-16.16.3-1
linuxlinux_kernel>= 0 < 5.15.0-163.1735.15.0-163.173
linuxlinux_kernel>= 4.1 < 5.4.2975.4.297
linuxlinux_kernel>= 5.11 < 5.15.1905.15.190
linuxlinux_kernel>= 5.16 < 6.1.1486.1.148
linuxlinux_kernel>= 5.5 < 5.10.2415.10.241
linuxlinux_kernel>= 6.13 < 6.15.106.15.10
linuxlinux_kernel>= 6.16 < 6.16.16.16.1
linuxlinux_kernel>= 6.2 < 6.6.1026.6.102

CVSS provenance

nvdv3.17.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
osv7.8HIGH