In the Linux kernel, the following vulnerability has been resolved:
habanalabs: fix UAF in export_dmabuf()
As soon as we'd inserted a file reference into descriptor table, another
thread could close it. That's fine for the case when all we are doing is
returning that descriptor to userland (it's a race, but it's a userland
race and there's nothing the kernel can do about it). However, if we
follow fd_install() with any kind of access to objects that would be
destroyed on close (be it the struct file itself or anything destroyed
by its ->release()), we have a UAF.
dma_buf_fd() is a combination of reserving a descriptor and fd_install().
habanalabs export_dmabuf() calls it and then proceeds to access the
objects destroyed on close. In particular, it grabs an extra reference to
another struct file that will be dropped as part of ->release() for ours;
that "will be" is actually "might have already been".
Fix that by reserving descriptor before anything else and do fd_install()
only when everything had been set up. As a side benefit, we no longer
have the failure exit with file already created, but reference to
underlying file (as well as ->dmabuf_export_cnt, etc.) not grabbed yet;
unlike dma_buf_fd(), fd_install() can't fail.
Metrics
Affected Vendors & Products
| Vendors | Products |
|---|---|
| Linux |
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No data.
No data.
References
History
Fri, 05 Sep 2025 14:15:00 +0000
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| First Time appeared |
Linux
Linux linux Kernel |
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| Vendors & Products |
Linux
Linux linux Kernel |
Fri, 05 Sep 2025 00:15:00 +0000
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| References |
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| Metrics |
threat_severity
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cvssV3_1
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Thu, 04 Sep 2025 15:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: habanalabs: fix UAF in export_dmabuf() As soon as we'd inserted a file reference into descriptor table, another thread could close it. That's fine for the case when all we are doing is returning that descriptor to userland (it's a race, but it's a userland race and there's nothing the kernel can do about it). However, if we follow fd_install() with any kind of access to objects that would be destroyed on close (be it the struct file itself or anything destroyed by its ->release()), we have a UAF. dma_buf_fd() is a combination of reserving a descriptor and fd_install(). habanalabs export_dmabuf() calls it and then proceeds to access the objects destroyed on close. In particular, it grabs an extra reference to another struct file that will be dropped as part of ->release() for ours; that "will be" is actually "might have already been". Fix that by reserving descriptor before anything else and do fd_install() only when everything had been set up. As a side benefit, we no longer have the failure exit with file already created, but reference to underlying file (as well as ->dmabuf_export_cnt, etc.) not grabbed yet; unlike dma_buf_fd(), fd_install() can't fail. | |
| Title | habanalabs: fix UAF in export_dmabuf() | |
| References |
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published: 2025-09-04T15:33:15.641Z
Updated: 2025-09-04T15:33:15.641Z
Reserved: 2025-04-16T04:51:24.033Z
Link: CVE-2025-38722
Vulnrichment
No data.
NVD
Status : Awaiting Analysis
Published: 2025-09-04T16:15:41.993
Modified: 2025-09-05T17:47:24.833
Link: CVE-2025-38722
Redhat