diff --git a/fs/coredump.c b/fs/coredump.c index b696dc2c220d..a8f75640ac86 100644 --- 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))