From: Peter Seiderer Date: Mon, 17 Mar 2025 09:04:00 +0000 (+0100) Subject: net: pktgen: add strict buffer parsing index check X-Git-Tag: v6.15-rc1~160^2~53 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7151062c297cc500d2a3b3723c83ff15f65332b4;p=thirdparty%2Fkernel%2Fstable.git net: pktgen: add strict buffer parsing index check Add strict buffer parsing index check to avoid the following Smatch warning: net/core/pktgen.c:877 get_imix_entries() warn: check that incremented offset 'i' is capped Checking the buffer index i after every get_user/i++ step and returning with error code immediately avoids the current indirect (but correct) error handling. Reported-by: Dan Carpenter Closes: https://lore.kernel.org/netdev/36cf3ee2-38b1-47e5-a42a-363efeb0ace3@stanley.mountain/ Signed-off-by: Peter Seiderer Reviewed-by: Simon Horman Link: https://patch.msgid.link/20250317090401.1240704-1-ps.report@gmx.net Signed-off-by: Jakub Kicinski --- diff --git a/net/core/pktgen.c b/net/core/pktgen.c index e850598db3e70..fe7fdefab994c 100644 --- a/net/core/pktgen.c +++ b/net/core/pktgen.c @@ -856,6 +856,9 @@ static ssize_t get_imix_entries(const char __user *buffer, if (pkt_dev->n_imix_entries >= MAX_IMIX_ENTRIES) return -E2BIG; + if (i >= maxlen) + return -EINVAL; + max = min(10, maxlen - i); len = num_arg(&buffer[i], max, &size); if (len < 0) @@ -869,6 +872,8 @@ static ssize_t get_imix_entries(const char __user *buffer, if (c != ',') return -EINVAL; i++; + if (i >= maxlen) + return -EINVAL; if (size < 14 + 20 + 8) size = 14 + 20 + 8; @@ -911,6 +916,9 @@ static ssize_t get_labels(const char __user *buffer, if (n >= MAX_MPLS_LABELS) return -E2BIG; + if (i >= maxlen) + return -EINVAL; + max = min(8, maxlen - i); len = hex32_arg(&buffer[i], max, &tmp); if (len < 0)