Linux Kernel up to 6.18.44/7.1.8 XFS xfs_buf_free b_addr null pointer dereference

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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6.2$0-$5k3.47

Summaryinfo

A vulnerability marked as critical has been reported in Linux Kernel up to 6.18.44/7.1.8. Affected is the function xfs_buf_free of the component XFS. Performing a manipulation of the argument b_addr results in null pointer dereference. This vulnerability was named CVE-2026-74728. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.18.44/7.1.8. It has been classified as critical. This affects the function xfs_buf_free of the component XFS. The manipulation of the argument b_addr with an unknown input leads to a null pointer dereference vulnerability. CWE is classifying the issue as CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. This is going to have an impact on availability. The summary by CVE is:

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->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->b_addr is NULL.

It is possible to read the advisory at git.kernel.org. This vulnerability is uniquely identified as CVE-2026-74728 since 08/15/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 08/22/2026).

Upgrading to version 6.18.45 or 7.1.9 eliminates this vulnerability. Applying the patch ccf6738adcafa5ddbddc4e71b45d8a51b86643c7/3aa0c1d23ee1b9d9b340fb2f4736536e1408d706/d852729c5f4f830fbe7413df032e29459b3daf83 is able to eliminate this problem.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-64415). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.5
VulDB Meta Temp Score: 6.2

VulDB Base Score: 6.5
VulDB Temp Score: 6.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.18.45/7.1.9
Patch: ccf6738adcafa5ddbddc4e71b45d8a51b86643c7/3aa0c1d23ee1b9d9b340fb2f4736536e1408d706/d852729c5f4f830fbe7413df032e29459b3daf83

Timelineinfo

08/15/2026 CVE reserved
08/22/2026 +7 days Advisory disclosed
08/22/2026 +0 days VulDB entry created
08/22/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-74728 (🔒)
GCVE (CVE): GCVE-0-2026-74728
GCVE (VulDB): GCVE-100-394503
EUVD: 🔒

Entryinfo

Created: 08/22/2026 19:08
Updated: 08/22/2026 19:20
Changes: 08/22/2026 19:08 (60), 08/22/2026 19:20 (1)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

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