From 770f60586d2af0590be263f55fd079226313922c Mon Sep 17 00:00:00 2001 From: Madhuparna Bhowmik Date: Thu, 30 Apr 2020 21:32:05 +0530 Subject: evm: Fix RCU list related warnings This patch fixes the following warning and few other instances of traversal of evm_config_xattrnames list: [ 32.848432] ============================= [ 32.848707] WARNING: suspicious RCU usage [ 32.848966] 5.7.0-rc1-00006-ga8d5875ce5f0b #1 Not tainted [ 32.849308] ----------------------------- [ 32.849567] security/integrity/evm/evm_main.c:231 RCU-list traversed in non-reader section!! Since entries are only added to the list and never deleted, use list_for_each_entry_lockless() instead of list_for_each_entry_rcu for traversing the list. Also, add a relevant comment in evm_secfs.c to indicate this fact. Reported-by: kernel test robot Suggested-by: Paul E. McKenney Signed-off-by: Madhuparna Bhowmik Acked-by: Paul E. McKenney (RCU viewpoint) Signed-off-by: Mimi Zohar --- security/integrity/evm/evm_main.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'security/integrity/evm/evm_main.c') diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c index d361d7fdafc4..0d36259b690d 100644 --- a/security/integrity/evm/evm_main.c +++ b/security/integrity/evm/evm_main.c @@ -97,7 +97,7 @@ static int evm_find_protected_xattrs(struct dentry *dentry) if (!(inode->i_opflags & IOP_XATTR)) return -EOPNOTSUPP; - list_for_each_entry_rcu(xattr, &evm_config_xattrnames, list) { + list_for_each_entry_lockless(xattr, &evm_config_xattrnames, list) { error = __vfs_getxattr(dentry, inode, xattr->name, NULL, 0); if (error < 0) { if (error == -ENODATA) @@ -228,7 +228,7 @@ static int evm_protected_xattr(const char *req_xattr_name) struct xattr_list *xattr; namelen = strlen(req_xattr_name); - list_for_each_entry_rcu(xattr, &evm_config_xattrnames, list) { + list_for_each_entry_lockless(xattr, &evm_config_xattrnames, list) { if ((strlen(xattr->name) == namelen) && (strncmp(req_xattr_name, xattr->name, namelen) == 0)) { found = 1; -- cgit v1.2.3