CVE-2026-89830

Summary

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

f2fs: fix valid block count leak on data block allocation failure

In __allocate_data_block(), when allocating a new data block (dn->data_blkaddr == NULL_ADDR), inc_valid_block_count() is called first to increment total_valid_block_count and i_blocks. If the subsequent f2fs_allocate_data_block() fails, the function returns the error directly without rolling back the already-incremented block counts, causing a permanent leak.

Fix this by calling dec_valid_block_count() to undo the increment before returning the error. The condition old_blkaddr == NULL_ADDR precisely identifies the case where inc_valid_block_count() was called.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux7d009e048d7cfcc21d400f2aba4c8bacbdebbd47 < 2d50b6d47e5671ff6a25834c5906d443356191f0affected
LinuxLinux7d009e048d7cfcc21d400f2aba4c8bacbdebbd47 < dde99df5a9d3b0ca6ac0a86f98799685f7399432affected
LinuxLinux7d009e048d7cfcc21d400f2aba4c8bacbdebbd47 < 931e1aa4d44c52ff8e0feb38420a8827c62e886baffected
LinuxLinux7d009e048d7cfcc21d400f2aba4c8bacbdebbd47 < 0f9af07ecc1ab486038373db6ae0436c5d674b19affected
LinuxLinux6.9affected
LinuxLinux0 < 6.9unaffected
LinuxLinux6.12.110 <= 6.12.*unaffected
LinuxLinux6.18.51 <= 6.18.*unaffected
LinuxLinux7.2.5 <= 7.2.*unaffected
LinuxLinux7.3-rc1 <= *unaffected

Weaknesses

References