From fe80f47b0ae8902d229ef9b8a1b4fa949b92e720 Mon Sep 17 00:00:00 2001
From: Jakub Jelen <jjelen@redhat.com>
Date: Tue, 27 Jun 2023 14:56:14 +0200
Subject: [PATCH] sftpserver: Add missing allocation check that might cause
 NULL dereference

Originally reported by Wei Chong Tan <shellcurity at protonmail.com>

Signed-off-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
Reviewed-by: Norbert Pocs <npocs@redhat.com>
---
 src/sftpserver.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/sftpserver.c b/src/sftpserver.c
index 8f15f39e..7d8070b1 100644
--- a/src/sftpserver.c
+++ b/src/sftpserver.c
@@ -962,6 +962,12 @@ process_read(sftp_client_message client_msg)
     }
 
     buffer = malloc(client_msg->len);
+    if (buffer == NULL) {
+        ssh_set_error_oom(sftp->session);
+        sftp_reply_status(client_msg, SSH_FX_FAILURE, NULL);
+        SSH_LOG(SSH_LOG_PROTOCOL, "Failed to allocate memory for read data");
+        return SSH_ERROR;
+    }
     do {
         ssize_t readn = read(fd, buffer + allreadn, client_msg->len - allreadn);
         if (readn < 0) {