What’s Vulnerable › Vulnerabilities

CVE-2026-74728: xfs: handle NULL b_addr in xfs_buf_free

• Severity: unknown
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-22 · updated 2026-10-21

Description

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.

Affected products

• Linux kernel: 6.9 — fixed in 7.2

How to fix

Upgrade to a fixed version: Linux kernel 7.2. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/3aa0c1d23ee1b9d9b340fb2f4736536e1408d706
• https://git.kernel.org/stable/c/444ff50ece93060131ad84fbd3f378723d8ac243
• https://git.kernel.org/stable/c/ccf6738adcafa5ddbddc4e71b45d8a51b86643c7
• https://git.kernel.org/stable/c/d852729c5f4f830fbe7413df032e29459b3daf83

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