<Vulnerability name="CVE-2026-74728">
    <DocumentDistribution xml:lang="en">Copyright © 2012 Red Hat, Inc. All rights reserved.</DocumentDistribution>
    <ThreatSeverity>Low</ThreatSeverity>
    <PublicDate>2026-08-22T00:00:00</PublicDate>
    <Bugzilla id="2521455" url="https://bugzilla.redhat.com/show_bug.cgi?id=2521455" xml:lang="en:us">
kernel: xfs: handle NULL b_addr in xfs_buf_free
    </Bugzilla>
    <CVSS3 status="draft">
        <CVSS3BaseScore>5.5</CVSS3BaseScore>
        <CVSS3ScoringVector>CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H</CVSS3ScoringVector>
    </CVSS3>
    <CWE>CWE-476</CWE>
    <Details xml:lang="en:us" source="Mitre">
In the Linux kernel, the following vulnerability has been resolved:

xfs: handle NULL b_addr in xfs_buf_free

When xfs_buf_alloc_backing_mem() fails, xfs_buf_free() is called with
bp-&gt;b_addr still NULL.  The code falls through to the folio_put path
which calls virt_to_folio(NULL), dereferencing an invalid address and
causing a kernel crash.

 Call Trace:
  xfs_buf_free+0x25f/0x510
  xfs_buf_alloc+0xc98/0x19b0
  xfs_buf_find_insert+0x55/0x14d0
  xfs_buf_get_map+0x122b/0x17c0
  xfbtree_init_leaf_block+0x11c/0x4a0
  xfbtree_init+0x1bb/0x460
  xrep_rmap_setup_scan+0x100/0x1f0
  xrep_rmapbt+0x41/0xc0

Fix this by skipping folio_put() when bp-&gt;b_addr is NULL.
    </Details>
    <Details xml:lang="en:us" source="Red Hat">
A flaw was found in the Linux kernel's XFS filesystem. When the system attempts to allocate memory for an XFS buffer and that allocation fails, the `xfs_buf_free` function is called with a null buffer address. This leads to a null pointer dereference, causing the kernel to crash. This vulnerability can result in a Denial of Service (DoS) for the affected system.
    </Details>
    <PackageState cpe="cpe:/o:redhat:enterprise_linux:10">
        <ProductName>Red Hat Enterprise Linux 10</ProductName>
        <FixState>Fix deferred</FixState>
        <PackageName>kernel</PackageName>
    </PackageState>
    <PackageState cpe="cpe:/o:redhat:enterprise_linux:6">
        <ProductName>Red Hat Enterprise Linux 6</ProductName>
        <FixState>Not affected</FixState>
        <PackageName>kernel</PackageName>
    </PackageState>
    <PackageState cpe="cpe:/o:redhat:enterprise_linux:7">
        <ProductName>Red Hat Enterprise Linux 7</ProductName>
        <FixState>Not affected</FixState>
        <PackageName>kernel</PackageName>
    </PackageState>
    <PackageState cpe="cpe:/o:redhat:enterprise_linux:7">
        <ProductName>Red Hat Enterprise Linux 7</ProductName>
        <FixState>Not affected</FixState>
        <PackageName>kernel-rt</PackageName>
    </PackageState>
    <PackageState cpe="cpe:/o:redhat:enterprise_linux:8">
        <ProductName>Red Hat Enterprise Linux 8</ProductName>
        <FixState>Not affected</FixState>
        <PackageName>kernel</PackageName>
    </PackageState>
    <PackageState cpe="cpe:/o:redhat:enterprise_linux:8">
        <ProductName>Red Hat Enterprise Linux 8</ProductName>
        <FixState>Not affected</FixState>
        <PackageName>kernel-rt</PackageName>
    </PackageState>
    <PackageState cpe="cpe:/o:redhat:enterprise_linux:9">
        <ProductName>Red Hat Enterprise Linux 9</ProductName>
        <FixState>Fix deferred</FixState>
        <PackageName>kernel</PackageName>
    </PackageState>
    <PackageState cpe="cpe:/o:redhat:enterprise_linux:9">
        <ProductName>Red Hat Enterprise Linux 9</ProductName>
        <FixState>Fix deferred</FixState>
        <PackageName>kernel-rt</PackageName>
    </PackageState>
    <References xml:lang="en:us">
https://www.cve.org/CVERecord?id=CVE-2026-74728
https://nvd.nist.gov/vuln/detail/CVE-2026-74728
https://lore.kernel.org/linux-cve-announce/2026082241-CVE-2026-74728-3d34@gregkh/T
    </References>
</Vulnerability>