Commit d7d82496 authored by Ernesto A. Fernández's avatar Ernesto A. Fernández Committed by David Sterba

btrfs: preserve i_mode if __btrfs_set_acl() fails

When changing a file's acl mask, btrfs_set_acl() will first set the
group bits of i_mode to the value of the mask, and only then set the
actual extended attribute representing the new acl.

If the second part fails (due to lack of space, for example) and the
file had no acl attribute to begin with, the system will from now on
assume that the mask permission bits are actual group permission bits,
potentially granting access to the wrong users.

Prevent this by restoring the original mode bits if __btrfs_set_acl
fails.
Signed-off-by: default avatarErnesto A. Fernández <ernesto.mnd.fernandez@gmail.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 408fbf19
...@@ -114,13 +114,17 @@ static int __btrfs_set_acl(struct btrfs_trans_handle *trans, ...@@ -114,13 +114,17 @@ static int __btrfs_set_acl(struct btrfs_trans_handle *trans,
int btrfs_set_acl(struct inode *inode, struct posix_acl *acl, int type) int btrfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
{ {
int ret; int ret;
umode_t old_mode = inode->i_mode;
if (type == ACL_TYPE_ACCESS && acl) { if (type == ACL_TYPE_ACCESS && acl) {
ret = posix_acl_update_mode(inode, &inode->i_mode, &acl); ret = posix_acl_update_mode(inode, &inode->i_mode, &acl);
if (ret) if (ret)
return ret; return ret;
} }
return __btrfs_set_acl(NULL, inode, acl, type); ret = __btrfs_set_acl(NULL, inode, acl, type);
if (ret)
inode->i_mode = old_mode;
return ret;
} }
/* /*
......
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