CVE-2026-74487

Summary

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

binfmt_misc: restore write access when removing an entry

Registering an entry with the MISC_FMT_OPEN_FILE flag opens the interpreter via open_exec() which denies write access to it for as long as the entry exists. Removing the entry closes the interpreter file via filp_close() but never restores write access, leaving the inode's i_writecount permanently negative. Opening the interpreter for writing keeps failing with ETXTBSY long after the entry is gone until the inode is evicted from the inode cache.

Commit 90f601b497d7 ("binfmt_misc: restore write access before closing files opened by open_exec()") fixed the same imbalance in the error path of bm_register_write() but the actual removal path has been leaking the write denial since the introduction of the flag.

Restore write access in put_binfmt_handler() before closing the interpreter file.

Affected Software

Weaknesses

References

• https://git.kernel.org/stable/c/fdc1d702bf3001586221fa07e598e876a0a854c5
• https://git.kernel.org/stable/c/3b522487a3a9162b1b519eefde7998d103e3e07b
• https://git.kernel.org/stable/c/db1856ea9196cf6e015d12199a34c0b9313c7bfa

• ←Previous
• Next→