CVE-2026-74728

Summary

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 Software

VendorProductVersion RangeStatus
LinuxLinux5076a6040ca1613e616d84aecfaac5f932db84e0 < ccf6738adcafa5ddbddc4e71b45d8a51b86643c7affected
LinuxLinux5076a6040ca1613e616d84aecfaac5f932db84e0 < 3aa0c1d23ee1b9d9b340fb2f4736536e1408d706affected
LinuxLinux5076a6040ca1613e616d84aecfaac5f932db84e0 < d852729c5f4f830fbe7413df032e29459b3daf83affected
LinuxLinux6.9affected
LinuxLinux0 < 6.9unaffected
LinuxLinux6.18.45 <= 6.18.*unaffected
LinuxLinux7.1.9 <= 7.1.*unaffected
LinuxLinux7.2 <= *unaffected

Weaknesses

References