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. Fixes: 948b701a607f ("binfmt_misc: add persistent opened binary handler for containers") Cc: stable@vger.kernel.org Signed-off-by: Christian Brauner (Amutable) --- fs/binfmt_misc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c index 84349fcb93f1..de50a7468b07 100644 --- a/fs/binfmt_misc.c +++ b/fs/binfmt_misc.c @@ -162,8 +162,10 @@ static Node *get_binfmt_handler(struct binfmt_misc *misc, static void put_binfmt_handler(Node *e) { if (refcount_dec_and_test(&e->users)) { - if (e->flags & MISC_FMT_OPEN_FILE) + if (e->flags & MISC_FMT_OPEN_FILE) { + exe_file_allow_write_access(e->interp_file); filp_close(e->interp_file, NULL); + } kfree(e); } } -- 2.53.0