IMA: update ima_counts_put
- As ima_counts_put() may be called after the inode has been freed, verify that the inode is not NULL, before dereferencing it. - Maintain the IMA file counters in may_open() properly, decrementing any counter increments on subsequent errors. Reported-by: Ciprian Docan <docan@eden.rutgers.edu> Reported-by: J.R. Okajima <hooanon05@yahoo.co.jp> Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Acked-by: Eric Paris <eparis@redhat.com Signed-off-by: James Morris <jmorris@namei.org>
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e07cccf404
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2 changed files with 20 additions and 8 deletions
22
fs/namei.c
22
fs/namei.c
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@ -1542,28 +1542,31 @@ int may_open(struct path *path, int acc_mode, int flag)
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* An append-only file must be opened in append mode for writing.
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*/
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if (IS_APPEND(inode)) {
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error = -EPERM;
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if ((flag & FMODE_WRITE) && !(flag & O_APPEND))
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return -EPERM;
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goto err_out;
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if (flag & O_TRUNC)
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return -EPERM;
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goto err_out;
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}
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/* O_NOATIME can only be set by the owner or superuser */
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if (flag & O_NOATIME)
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if (!is_owner_or_cap(inode))
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return -EPERM;
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if (!is_owner_or_cap(inode)) {
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error = -EPERM;
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goto err_out;
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}
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/*
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* Ensure there are no outstanding leases on the file.
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*/
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error = break_lease(inode, flag);
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if (error)
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return error;
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goto err_out;
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if (flag & O_TRUNC) {
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error = get_write_access(inode);
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if (error)
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return error;
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goto err_out;
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/*
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* Refuse to truncate files with mandatory locks held on them.
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@ -1581,12 +1584,17 @@ int may_open(struct path *path, int acc_mode, int flag)
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}
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put_write_access(inode);
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if (error)
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return error;
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goto err_out;
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} else
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if (flag & FMODE_WRITE)
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vfs_dq_init(inode);
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return 0;
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err_out:
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ima_counts_put(path, acc_mode ?
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acc_mode & (MAY_READ | MAY_WRITE | MAY_EXEC) :
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ACC_MODE(flag) & (MAY_READ | MAY_WRITE));
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return error;
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}
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/*
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@ -249,7 +249,11 @@ void ima_counts_put(struct path *path, int mask)
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struct inode *inode = path->dentry->d_inode;
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struct ima_iint_cache *iint;
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if (!ima_initialized || !S_ISREG(inode->i_mode))
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/* The inode may already have been freed, freeing the iint
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* with it. Verify the inode is not NULL before dereferencing
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* it.
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*/
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if (!ima_initialized || !inode || !S_ISREG(inode->i_mode))
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return;
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iint = ima_iint_find_insert_get(inode);
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if (!iint)
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