cbcvebase.
CVE-2026-43158
published 2026-05-06

CVE-2026-43158: In the Linux kernel, the following vulnerability has been resolved: xfs: fix freemap adjustments when adding xattrs to leaf blocks xfs/592 and xfs/794 both…

PriorityP351high8.8CVSS 3.1
AVNACLPRLUINSUCHIHAH
EPSS
0.47%
37.6th percentile
In the Linux kernel, the following vulnerability has been resolved: xfs: fix freemap adjustments when adding xattrs to leaf blocks xfs/592 and xfs/794 both trip this assertion in the leaf block freemap adjustment code after ~20 minutes of running on my test VMs: ASSERT(ichdr->firstused >= ichdr->count * sizeof(xfs_attr_leaf_entry_t) + xfs_attr3_leaf_hdr_size(leaf)); Upon enabling quite a lot more debugging code, I narrowed this down to fsstress trying to set a local extended attribute with namelen=3 and valuelen=71. This results in an entry size of 80 bytes. At the start of xfs_attr3_leaf_add_work, the freemap looks like this: i 0 base 448 size 0 rhs 448 count 46 i 1 base 388 size 132 rhs 448 count 46 i 2 base 2120 size 4 rhs 448 count 46 firstused = 520 where "rhs" is the first byte past the end of the leaf entry array. This is inconsistent -- the entries array ends at byte 448, but freemap[1] says there's free space starting at byte 388! By the end of the function, the freemap is in worse shape: i 0 base 456 size 0 rhs 456 count 47 i 1 base 388 size 52 rhs 456 count 47 i 2 base 2120 size 4 rhs 456 count 47 firstused = 440 Important note: 388 is not aligned with the entries array element size of 8 bytes. Based on the incorrect freemap, the name area starts at byte 440, which is below the end of the entries array! That's why the assertion triggers and the filesystem shuts down. How did we end up here? First, recall from the previous patch that the freemap array in an xattr leaf block is not intended to be a comprehensive map of all free space in the leaf block. In other words, it's perfectly legal to have a leaf block with: * 376 bytes in use by the entries array * freemap[0] has [base = 376, size = 8] * freemap[1] has [base = 388, size = 1500] * the space between 376 and 388 is free, but the freemap stopped tracking that some time ago If we add one xattr, the entries array grows to 384 bytes, and freemap[0] becomes [base = 384, size = 0]. So far, so g

Affected

44 ranges· showing 25
VendorProductVersion rangeFixed in
linuxlinux
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < d08976725355b9d54d8332fce223fa281cc304a5d08976725355b9d54d8332fce223fa281cc304a5
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 6a8737afbccc340e718e0b22577312826390be8b6a8737afbccc340e718e0b22577312826390be8b
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < a396b3d73d51355e50acdb403ba9c4cae4c1174ea396b3d73d51355e50acdb403ba9c4cae4c1174e
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 38613c01f69e1e77e6b8acab1e8ac665d01c2f1538613c01f69e1e77e6b8acab1e8ac665d01c2f15
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < ef42a8766ff3fdf51cf72fb36d0859c09d134478ef42a8766ff3fdf51cf72fb36d0859c09d134478
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 43f3b18679615a93bd848afde3602ba160637a4643f3b18679615a93bd848afde3602ba160637a46
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 24ce71852f2cee6581e2cbebc15489ed52bf63b724ce71852f2cee6581e2cbebc15489ed52bf63b7
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 3eefc0c2b78444b64feeb3783c017d6adc3cd3ce3eefc0c2b78444b64feeb3783c017d6adc3cd3ce
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel>= 2.6.12.1 < 5.10.2525.10.252
linuxlinux_kernel>= 5.11 < 5.15.2025.15.202
linuxlinux_kernel>= 5.16 < 6.1.1656.1.165
linuxlinux_kernel>= 6.13 < 6.18.166.18.16
linuxlinux_kernel>= 6.19 < 6.19.66.19.6
linuxlinux_kernel>= 6.2 < 6.6.1286.6.128
linuxlinux_kernel>= 6.7 < 6.12.756.12.75
ubuntulinux
ubuntulinux-aws
ubuntulinux-aws-6.8
ubuntulinux-aws-fips
ubuntulinux-azure-fips
ubuntulinux-fips
ubuntulinux-gcp

CVSS provenance

nvdv3.18.8HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
vendor_ubuntu8.8HIGH
vendor_redhat7.0HIGH
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