diff options
Diffstat (limited to 'fs/exec.c')
| -rw-r--r-- | fs/exec.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/fs/exec.c b/fs/exec.c index c72ccfa49f54..2e26ba4ff47e 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1788,6 +1788,9 @@ static int do_execveat_common(int fd, struct filename *filename, goto out_unmark; bprm->argc = count(argv, MAX_ARG_STRINGS); + if (bprm->argc == 0) + pr_warn_once("process '%s' launched '%s' with NULL argv: empty string added\n", + current->comm, bprm->filename); if ((retval = bprm->argc) < 0) goto out; @@ -1812,6 +1815,20 @@ static int do_execveat_common(int fd, struct filename *filename, if (retval < 0) goto out; + /* + * When argv is empty, add an empty string ("") as argv[0] to + * ensure confused userspace programs that start processing + * from argv[1] won't end up walking envp. See also + * bprm_stack_limits(). + */ + if (bprm->argc == 0) { + const char *argv[] = { "", NULL }; + retval = copy_strings_kernel(1, argv, bprm); + if (retval < 0) + goto out; + bprm->argc = 1; + } + retval = exec_binprm(bprm); if (retval < 0) goto out; |