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| author | Mimi Zohar <zohar@linux.vnet.ibm.com> | 2009-09-04 19:08:46 +0200 |
|---|---|---|
| committer | James Morris <jmorris@namei.org> | 2009-09-07 03:54:58 +0200 |
| commit | acd0c935178649f72c44ec49ca83bee35ce1f79e (patch) | |
| tree | c0cb2f8fbbaa54567785b5430e5be8c8b51f5724 | |
| parent | Linux 2.6.31-rc9 (diff) | |
| download | linux-acd0c935178649f72c44ec49ca83bee35ce1f79e.tar.xz linux-acd0c935178649f72c44ec49ca83bee35ce1f79e.zip | |
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>
| -rw-r--r-- | fs/namei.c | 22 | ||||
| -rw-r--r-- | security/integrity/ima/ima_main.c | 6 |
2 files changed, 20 insertions, 8 deletions
diff --git a/fs/namei.c b/fs/namei.c index f3c5b278895a..1f13751693a5 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1542,28 +1542,31 @@ int may_open(struct path *path, int acc_mode, int flag) * An append-only file must be opened in append mode for writing. */ if (IS_APPEND(inode)) { + error = -EPERM; if ((flag & FMODE_WRITE) && !(flag & O_APPEND)) - return -EPERM; + goto err_out; if (flag & O_TRUNC) - return -EPERM; + goto err_out; } /* O_NOATIME can only be set by the owner or superuser */ if (flag & O_NOATIME) - if (!is_owner_or_cap(inode)) - return -EPERM; + if (!is_owner_or_cap(inode)) { + error = -EPERM; + goto err_out; + } /* * Ensure there are no outstanding leases on the file. */ error = break_lease(inode, flag); if (error) - return error; + goto err_out; if (flag & O_TRUNC) { error = get_write_access(inode); if (error) - return error; + goto err_out; /* * Refuse to truncate files with mandatory locks held on them. @@ -1581,12 +1584,17 @@ int may_open(struct path *path, int acc_mode, int flag) } put_write_access(inode); if (error) - return error; + goto err_out; } else if (flag & FMODE_WRITE) vfs_dq_init(inode); return 0; +err_out: + ima_counts_put(path, acc_mode ? + acc_mode & (MAY_READ | MAY_WRITE | MAY_EXEC) : + ACC_MODE(flag) & (MAY_READ | MAY_WRITE)); + return error; } /* diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 4732f5e5d127..b85e61bcf246 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -249,7 +249,11 @@ void ima_counts_put(struct path *path, int mask) struct inode *inode = path->dentry->d_inode; struct ima_iint_cache *iint; - if (!ima_initialized || !S_ISREG(inode->i_mode)) + /* The inode may already have been freed, freeing the iint + * with it. Verify the inode is not NULL before dereferencing + * it. + */ + if (!ima_initialized || !inode || !S_ISREG(inode->i_mode)) return; iint = ima_iint_find_insert_get(inode); if (!iint) |