1 files changed, 17 insertions, 0 deletions

diff --git a/fs/exec.c b/fs/exec.c
index da80612a35f4..25dcbe5fc356 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1459,6 +1459,23 @@ static int do_execve_common(const char *filename,
         struct files_struct *displaced;
         bool clear_in_exec;
         int retval;
+        const struct cred *cred = current_cred();
+
+        /*
+         * We move the actual failure in case of RLIMIT_NPROC excess from
+         * set*uid() to execve() because too many poorly written programs
+         * don't check setuid() return code.  Here we additionally recheck
+         * whether NPROC limit is still exceeded.
+         */
+        if ((current->flags & PF_NPROC_EXCEEDED) &&
+            atomic_read(&cred->user->processes) > rlimit(RLIMIT_NPROC)) {
+                retval = -EAGAIN;
+                goto out_ret;
+        }
+
+        /* We're below the limit (still or again), so we don't want to make
+         * further execve() calls fail. */
+        current->flags &= ~PF_NPROC_EXCEEDED;
 
         retval = unshare_files(&displaced);
         if (retval)