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-rw-r--r--fs/attr.c44
1 files changed, 30 insertions, 14 deletions
diff --git a/fs/attr.c b/fs/attr.c
index ed44d8ae8bf1..7ca41811afa1 100644
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -14,35 +14,53 @@
14#include <linux/fcntl.h> 14#include <linux/fcntl.h>
15#include <linux/security.h> 15#include <linux/security.h>
16 16
17/* Taken over from the old code... */ 17/**
18 18 * inode_change_ok - check if attribute changes to an inode are allowed
19/* POSIX UID/GID verification for setting inode attributes. */ 19 * @inode: inode to check
20 * @attr: attributes to change
21 *
22 * Check if we are allowed to change the attributes contained in @attr
23 * in the given inode. This includes the normal unix access permission
24 * checks, as well as checks for rlimits and others.
25 *
26 * Should be called as the first thing in ->setattr implementations,
27 * possibly after taking additional locks.
28 */
20int inode_change_ok(const struct inode *inode, struct iattr *attr) 29int inode_change_ok(const struct inode *inode, struct iattr *attr)
21{ 30{
22 int retval = -EPERM;
23 unsigned int ia_valid = attr->ia_valid; 31 unsigned int ia_valid = attr->ia_valid;
24 32
33 /*
34 * First check size constraints. These can't be overriden using
35 * ATTR_FORCE.
36 */
37 if (ia_valid & ATTR_SIZE) {
38 int error = inode_newsize_ok(inode, attr->ia_size);
39 if (error)
40 return error;
41 }
42
25 /* If force is set do it anyway. */ 43 /* If force is set do it anyway. */
26 if (ia_valid & ATTR_FORCE) 44 if (ia_valid & ATTR_FORCE)
27 goto fine; 45 return 0;
28 46
29 /* Make sure a caller can chown. */ 47 /* Make sure a caller can chown. */
30 if ((ia_valid & ATTR_UID) && 48 if ((ia_valid & ATTR_UID) &&
31 (current_fsuid() != inode->i_uid || 49 (current_fsuid() != inode->i_uid ||
32 attr->ia_uid != inode->i_uid) && !capable(CAP_CHOWN)) 50 attr->ia_uid != inode->i_uid) && !capable(CAP_CHOWN))
33 goto error; 51 return -EPERM;
34 52
35 /* Make sure caller can chgrp. */ 53 /* Make sure caller can chgrp. */
36 if ((ia_valid & ATTR_GID) && 54 if ((ia_valid & ATTR_GID) &&
37 (current_fsuid() != inode->i_uid || 55 (current_fsuid() != inode->i_uid ||
38 (!in_group_p(attr->ia_gid) && attr->ia_gid != inode->i_gid)) && 56 (!in_group_p(attr->ia_gid) && attr->ia_gid != inode->i_gid)) &&
39 !capable(CAP_CHOWN)) 57 !capable(CAP_CHOWN))
40 goto error; 58 return -EPERM;
41 59
42 /* Make sure a caller can chmod. */ 60 /* Make sure a caller can chmod. */
43 if (ia_valid & ATTR_MODE) { 61 if (ia_valid & ATTR_MODE) {
44 if (!is_owner_or_cap(inode)) 62 if (!is_owner_or_cap(inode))
45 goto error; 63 return -EPERM;
46 /* Also check the setgid bit! */ 64 /* Also check the setgid bit! */
47 if (!in_group_p((ia_valid & ATTR_GID) ? attr->ia_gid : 65 if (!in_group_p((ia_valid & ATTR_GID) ? attr->ia_gid :
48 inode->i_gid) && !capable(CAP_FSETID)) 66 inode->i_gid) && !capable(CAP_FSETID))
@@ -52,12 +70,10 @@ int inode_change_ok(const struct inode *inode, struct iattr *attr)
52 /* Check for setting the inode time. */ 70 /* Check for setting the inode time. */
53 if (ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)) { 71 if (ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)) {
54 if (!is_owner_or_cap(inode)) 72 if (!is_owner_or_cap(inode))
55 goto error; 73 return -EPERM;
56 } 74 }
57fine: 75
58 retval = 0; 76 return 0;
59error:
60 return retval;
61} 77}
62EXPORT_SYMBOL(inode_change_ok); 78EXPORT_SYMBOL(inode_change_ok);
63 79
@@ -113,7 +129,7 @@ EXPORT_SYMBOL(inode_newsize_ok);
113 * 129 *
114 * setattr_copy updates the inode's metadata with that specified 130 * setattr_copy updates the inode's metadata with that specified
115 * in attr. Noticably missing is inode size update, which is more complex 131 * in attr. Noticably missing is inode size update, which is more complex
116 * as it requires pagecache updates. See simple_setsize. 132 * as it requires pagecache updates.
117 * 133 *
118 * The inode is not marked as dirty after this operation. The rationale is 134 * The inode is not marked as dirty after this operation. The rationale is
119 * that for "simple" filesystems, the struct inode is the inode storage. 135 * that for "simple" filesystems, the struct inode is the inode storage.