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authorDarrick J. Wong <darrick.wong@oracle.com>2018-10-30 10:41:41 +1100
committerDave Chinner <david@fromorbit.com>2018-10-30 10:41:41 +1100
commit8dde90bca6fca3736ea20109654bcf6dcf2ecf1d (patch)
tree4ead8c271da07d766432bb0847026f73054842cd /fs/read_write.c
parent3d28193e1df043764deb7abdaba5e3a6660bc393 (diff)
vfs: remap helper should update destination inode metadata
Extend generic_remap_file_range_prep to handle inode metadata updates when remapping into a file. If the operation can possibly alter the file contents, we must update the ctime and mtime and remove security privileges, just like we do for regular file writes. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
Diffstat (limited to 'fs/read_write.c')
-rw-r--r--fs/read_write.c19
1 files changed, 19 insertions, 0 deletions
diff --git a/fs/read_write.c b/fs/read_write.c
index ebcbfc4f2907..b61bd3fc7154 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1820,6 +1820,25 @@ int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in,
if (ret)
return ret;
+ /* If can't alter the file contents, we're done. */
+ if (!(remap_flags & REMAP_FILE_DEDUP)) {
+ /* Update the timestamps, since we can alter file contents. */
+ if (!(file_out->f_mode & FMODE_NOCMTIME)) {
+ ret = file_update_time(file_out);
+ if (ret)
+ return ret;
+ }
+
+ /*
+ * Clear the security bits if the process is not being run by
+ * root. This keeps people from modifying setuid and setgid
+ * binaries.
+ */
+ ret = file_remove_privs(file_out);
+ if (ret)
+ return ret;
+ }
+
return 1;
}
EXPORT_SYMBOL(generic_remap_file_range_prep);