ima: use file_dentry()

commit e71b9dff0634edb127f449e076e883ef24a8c76c upstream.

Ima tries to call ->setxattr() on overlayfs dentry after having locked
underlying inode, which results in a deadlock.

Reported-by: Krisztian Litkey <kli@iki.fi>
Fixes: 4bacc9c9234c ("overlayfs: Make f_path always point to the overlay and f_inode to the underlay")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index 1d950fb..2d1fe34 100644 (file)
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -202,7 +202,7 @@ int ima_collect_measurement(struct integrity_iint_cache *iint,
        } hash;
 
        if (xattr_value)
-               *xattr_len = ima_read_xattr(file->f_path.dentry, xattr_value);
+               *xattr_len = ima_read_xattr(file_dentry(file), xattr_value);
 
        if (!(iint->flags & IMA_COLLECTED)) {
                u64 i_version = file_inode(file)->i_version;

diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
index 1873b55..ed5a9c1 100644 (file)
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -189,7 +189,7 @@ int ima_appraise_measurement(int func, struct integrity_iint_cache *iint,
 {
        static const char op[] = "appraise_data";
        char *cause = "unknown";
-       struct dentry *dentry = file->f_path.dentry;
+       struct dentry *dentry = file_dentry(file);
        struct inode *inode = d_backing_inode(dentry);
        enum integrity_status status = INTEGRITY_UNKNOWN;
        int rc = xattr_len, hash_start = 0;
@@ -289,7 +289,7 @@ out:
  */
 void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file)
 {
-       struct dentry *dentry = file->f_path.dentry;
+       struct dentry *dentry = file_dentry(file);
        int rc = 0;
 
        /* do not collect and update hash for digital signatures */