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authorOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>2008-06-13 02:21:28 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2008-06-13 05:05:39 +0400
commit2d518f84e5ecd1d71df0e6ac5176d212f68c27ce (patch)
treefd5c4e3b350f82e516c63349e17e43805c0899fb /fs/fat
parentc700be3d1320d2be4f04c8a5330186b7df724438 (diff)
downloadlinux-2d518f84e5ecd1d71df0e6ac5176d212f68c27ce.tar.xz
fat: relax the permission check of fat_setattr()
New chmod() allows only acceptable permission, and if not acceptable, it returns -EPERM. Old one allows even if it can't store permission to on disk inode. But it seems too strict for users. E.g. https://bugzilla.redhat.com/show_bug.cgi?id=449080: With new one, rsync couldn't create the temporary file. So, this patch allows like old one, but now it doesn't change the permission if it can't store, and it returns 0. Also, this patch fixes missing check. Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/fat')
-rw-r--r--fs/fat/file.c44
1 files changed, 27 insertions, 17 deletions
diff --git a/fs/fat/file.c b/fs/fat/file.c
index 27cc1164ec36..771326b8047e 100644
--- a/fs/fat/file.c
+++ b/fs/fat/file.c
@@ -257,26 +257,34 @@ int fat_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
}
EXPORT_SYMBOL_GPL(fat_getattr);
-static int fat_check_mode(const struct msdos_sb_info *sbi, struct inode *inode,
- mode_t mode)
+static int fat_sanitize_mode(const struct msdos_sb_info *sbi,
+ struct inode *inode, umode_t *mode_ptr)
{
- mode_t mask, req = mode & ~S_IFMT;
+ mode_t mask, perm;
- if (S_ISREG(mode))
+ /*
+ * Note, the basic check is already done by a caller of
+ * (attr->ia_mode & ~MSDOS_VALID_MODE)
+ */
+
+ if (S_ISREG(inode->i_mode))
mask = sbi->options.fs_fmask;
else
mask = sbi->options.fs_dmask;
+ perm = *mode_ptr & ~(S_IFMT | mask);
+
/*
* Of the r and x bits, all (subject to umask) must be present. Of the
* w bits, either all (subject to umask) or none must be present.
*/
- req &= ~mask;
- if ((req & (S_IRUGO | S_IXUGO)) != (inode->i_mode & (S_IRUGO|S_IXUGO)))
+ if ((perm & (S_IRUGO | S_IXUGO)) != (inode->i_mode & (S_IRUGO|S_IXUGO)))
return -EPERM;
- if ((req & S_IWUGO) && ((req & S_IWUGO) != (S_IWUGO & ~mask)))
+ if ((perm & S_IWUGO) && ((perm & S_IWUGO) != (S_IWUGO & ~mask)))
return -EPERM;
+ *mode_ptr &= S_IFMT | perm;
+
return 0;
}
@@ -299,7 +307,7 @@ int fat_setattr(struct dentry *dentry, struct iattr *attr)
{
struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb);
struct inode *inode = dentry->d_inode;
- int mask, error = 0;
+ int error = 0;
unsigned int ia_valid;
lock_kernel();
@@ -332,12 +340,13 @@ int fat_setattr(struct dentry *dentry, struct iattr *attr)
error = 0;
goto out;
}
+
if (((attr->ia_valid & ATTR_UID) &&
(attr->ia_uid != sbi->options.fs_uid)) ||
((attr->ia_valid & ATTR_GID) &&
(attr->ia_gid != sbi->options.fs_gid)) ||
((attr->ia_valid & ATTR_MODE) &&
- fat_check_mode(sbi, inode, attr->ia_mode) < 0))
+ (attr->ia_mode & ~MSDOS_VALID_MODE)))
error = -EPERM;
if (error) {
@@ -346,15 +355,16 @@ int fat_setattr(struct dentry *dentry, struct iattr *attr)
goto out;
}
- error = inode_setattr(inode, attr);
- if (error)
- goto out;
+ /*
+ * We don't return -EPERM here. Yes, strange, but this is too
+ * old behavior.
+ */
+ if (attr->ia_valid & ATTR_MODE) {
+ if (fat_sanitize_mode(sbi, inode, &attr->ia_mode) < 0)
+ attr->ia_valid &= ~ATTR_MODE;
+ }
- if (S_ISDIR(inode->i_mode))
- mask = sbi->options.fs_dmask;
- else
- mask = sbi->options.fs_fmask;
- inode->i_mode &= S_IFMT | (S_IRWXUGO & ~mask);
+ error = inode_setattr(inode, attr);
out:
unlock_kernel();
return error;