fs: Don't dump core if the corefile would become world-readable.

[tomoyo/tomoyo-test1.git] / fs / coredump.c

diff --git a/fs/coredump.c b/fs/coredump.c
index b696dc2..a8f7564 100644 (file)
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -685,11 +685,15 @@ void do_coredump(const siginfo_t *siginfo)
                if (!S_ISREG(inode->i_mode))
                        goto close_fail;
                /*
-                * Dont allow local users get cute and trick others to coredump
-                * into their pre-created files.
+                * Don't dump core if the filesystem changed owner or mode
+                * of the file during file creation. This is an issue when
+                * a process dumps core while its cwd is e.g. on a vfat
+                * filesystem.
                 */
                if (!uid_eq(inode->i_uid, current_fsuid()))
                        goto close_fail;
+               if ((inode->i_mode & 0677) != 0600)
+                       goto close_fail;
                if (!(cprm.file->f_mode & FMODE_CAN_WRITE))
                        goto close_fail;
                if (do_truncate(cprm.file->f_path.dentry, 0, 0, cprm.file))