CVE-2025-71292

Summary

In the Linux kernel, the following vulnerability has been resolved:

jfs: nlink overflow in jfs_rename

If nlink is maximal for a directory (-1) and inside that directory you perform a rename for some child directory (not moving from the parent), then the nlink of the first directory is first incremented and later decremented. Normally this is fine, but when nlink = -1 this causes a wrap around to 0, and then drop_nlink issues a warning.

After applying the patch syzbot no longer issues any warnings. I also ran some basic fs tests to look for any regressions.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 2108829a59f081e822fdab8c2cd7131deb8aa8a1affected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < b4330a0d0947fbdc9d445cbbeabd8cc910a8c9caaffected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < a3d66089e50a6e0142f8884471f74292102ea9aaaffected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < f70fcbc2ac7c24f087a2c895c5753aa730b1e479affected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 5d77c36cd4b698649f5c30c5f6c084f4f61d1880affected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < fe136426e30ca6debcf916fd6a141555ed9fde74affected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 93c325746ae59709b4f9bad4e3e4761c8d566c70affected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 9218dc26fd922b09858ecd3666ed57dfd8098da8affected
LinuxLinux2.6.12affected
LinuxLinux0 < 2.6.12unaffected
LinuxLinux5.10.252 <= 5.10.*unaffected
LinuxLinux5.15.202 <= 5.15.*unaffected
LinuxLinux6.1.165 <= 6.1.*unaffected
LinuxLinux6.6.128 <= 6.6.*unaffected
LinuxLinux6.12.75 <= 6.12.*unaffected
LinuxLinux6.18.16 <= 6.18.*unaffected
LinuxLinux6.19.6 <= 6.19.*unaffected
LinuxLinux7.0 <= *unaffected

Weaknesses

References