cbcvebase.
CVE-2023-52909
published 2024-08-21

CVE-2023-52909: In the Linux kernel, the following vulnerability has been resolved: nfsd: fix handling of cached open files in nfsd4_open codepath Commit fb70bf124b05 ("NFSD…

PriorityP418medium4.7CVSS 3.1
AVLACHPRLUINSUCNINAH
EPSS
0.64%
47.5th percentile
In the Linux kernel, the following vulnerability has been resolved: nfsd: fix handling of cached open files in nfsd4_open codepath Commit fb70bf124b05 ("NFSD: Instantiate a struct file when creating a regular NFSv4 file") added the ability to cache an open fd over a compound. There are a couple of problems with the way this currently works: It's racy, as a newly-created nfsd_file can end up with its PENDING bit cleared while the nf is hashed, and the nf_file pointer is still zeroed out. Other tasks can find it in this state and they expect to see a valid nf_file, and can oops if nf_file is NULL. Also, there is no guarantee that we'll end up creating a new nfsd_file if one is already in the hash. If an extant entry is in the hash with a valid nf_file, nfs4_get_vfs_file will clobber its nf_file pointer with the value of op_file and the old nf_file will leak. Fix both issues by making a new nfsd_file_acquirei_opened variant that takes an optional file pointer. If one is present when this is called, we'll take a new reference to it instead of trying to open the file. If the nfsd_file already has a valid nf_file, we'll just ignore the optional file and pass the nfsd_file back as-is. Also rework the tracepoints a bit to allow for an "opened" variant and don't try to avoid counting acquisitions in the case where we already have a cached open file.

Affected

14 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.1.7-1 (bookworm)linux 6.1.7-1 (bookworm)
linuxlinux
linuxlinux>= 106331a12b0fa5afa6995b1f9ebb03ddcaac6915 < 0b778361998d6c6356b8d2fc7ddf025fb32246540b778361998d6c6356b8d2fc7ddf025fb3224654
linuxlinux>= c20097329d2c196b818c4666c7820c1378d69d61 < 45c08a752982116f3287afcd1bd9c50f4fab0c2845c08a752982116f3287afcd1bd9c50f4fab0c28
linuxlinux>= fb70bf124b051d4ded4ce57511dfec6d3ebf2b43 < 973acfdfe90c8a4e58ade97ff0653a498531ff2e973acfdfe90c8a4e58ade97ff0653a498531ff2e
linuxlinux>= fb70bf124b051d4ded4ce57511dfec6d3ebf2b43 < 0b3a551fa58b4da941efeb209b3770868e2eddd70b3a551fa58b4da941efeb209b3770868e2eddd7
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel>= 0 < 5.10.221-15.10.221-1
linuxlinux_kernel>= 0 < 6.1.7-16.1.7-1
linuxlinux_kernel>= 0 < 6.1.7-16.1.7-1
linuxlinux_kernel>= 0 < 6.1.7-16.1.7-1
linuxlinux_kernel>= 5.19 < 6.1.76.1.7

CVSS provenance

nvdv3.14.7MEDIUMCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
osv4.7MEDIUM
vendor_debian4.7MEDIUM
vendor_redhat4.7MEDIUM
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