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authorLinus Torvalds <torvalds@linux-foundation.org>2019-07-10 20:32:37 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-07-10 20:32:37 -0700
commit40f06c799539739a08a56be8a096f56aeed05731 (patch)
treeb36fd977d7abaa5041222bd07e600938af28a0d1 /fs/inode.c
parenta47f5c56b2eb55290e2a8668e9ca9c029990dbf6 (diff)
parentfe0da9c09b2dc448ff781d1426ecb36d145ce51b (diff)
Merge tag 'copy-file-range-fixes-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull copy_file_range updates from Darrick Wong: "This fixes numerous parameter checking problems and inconsistent behaviors in the new(ish) copy_file_range system call. Now the system call will actually check its range parameters correctly; refuse to copy into files for which the caller does not have sufficient privileges; update mtime and strip setuid like file writes are supposed to do; and allows copying up to the EOF of the source file instead of failing the call like we used to. Summary: - Create a generic copy_file_range handler and make individual filesystems responsible for calling it (i.e. no more assuming that do_splice_direct will work or is appropriate) - Refactor copy_file_range and remap_range parameter checking where they are the same - Install missing copy_file_range parameter checking(!) - Remove suid/sgid and update mtime like any other file write - Change the behavior so that a copy range crossing the source file's eof will result in a short copy to the source file's eof instead of EINVAL - Permit filesystems to decide if they want to handle cross-superblock copy_file_range in their local handlers" * tag 'copy-file-range-fixes-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: fuse: copy_file_range needs to strip setuid bits and update timestamps vfs: allow copy_file_range to copy across devices xfs: use file_modified() helper vfs: introduce file_modified() helper vfs: add missing checks to copy_file_range vfs: remove redundant checks from generic_remap_checks() vfs: introduce generic_file_rw_checks() vfs: no fallback for ->copy_file_range vfs: introduce generic_copy_file_range()
Diffstat (limited to 'fs/inode.c')
-rw-r--r--fs/inode.c20
1 files changed, 20 insertions, 0 deletions
diff --git a/fs/inode.c b/fs/inode.c
index 2bf21e2c90fc..5f5431ec3d62 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -1899,6 +1899,26 @@ int file_update_time(struct file *file)
}
EXPORT_SYMBOL(file_update_time);
+/* Caller must hold the file's inode lock */
+int file_modified(struct file *file)
+{
+ int err;
+
+ /*
+ * Clear the security bits if the process is not being run by root.
+ * This keeps people from modifying setuid and setgid binaries.
+ */
+ err = file_remove_privs(file);
+ if (err)
+ return err;
+
+ if (unlikely(file->f_mode & FMODE_NOCMTIME))
+ return 0;
+
+ return file_update_time(file);
+}
+EXPORT_SYMBOL(file_modified);
+
int inode_needs_sync(struct inode *inode)
{
if (IS_SYNC(inode))