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From: David Gibson <david@gibson.dropbear.id.au>
To: passt-dev@passt.top, Stefano Brivio <sbrivio@redhat.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Subject: [PATCH v2 07/11] packet: Move checks against PACKET_MAX_LEN to packet_check_range()
Date: Mon, 17 Mar 2025 20:24:20 +1100	[thread overview]
Message-ID: <20250317092424.1461719-8-david@gibson.dropbear.id.au> (raw)
In-Reply-To: <20250317092424.1461719-1-david@gibson.dropbear.id.au>

Both the callers of packet_check_range() separately verify that the given
length does not exceed PACKET_MAX_LEN.  Fold that check into
packet_check_range() instead.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 packet.c | 19 ++++++-------------
 1 file changed, 6 insertions(+), 13 deletions(-)

diff --git a/packet.c b/packet.c
index fdc4be76..7cbe95da 100644
--- a/packet.c
+++ b/packet.c
@@ -35,6 +35,12 @@
 static int packet_check_range(const struct pool *p, const char *ptr, size_t len,
 			      const char *func, int line)
 {
+	if (len > PACKET_MAX_LEN) {
+		trace("packet range length %zu (max %zu), %s:%i",
+		      len, PACKET_MAX_LEN, func, line);
+		return -1;
+	}
+
 	if (p->buf_size == 0) {
 		int ret;
 
@@ -100,11 +106,6 @@ void packet_add_do(struct pool *p, size_t len, const char *start,
 	if (packet_check_range(p, start, len, func, line))
 		return;
 
-	if (len > PACKET_MAX_LEN) {
-		trace("add packet length %zu, %s:%i", len, func, line);
-		return;
-	}
-
 	p->pkt[idx].iov_base = (void *)start;
 	p->pkt[idx].iov_len = len;
 
@@ -136,14 +137,6 @@ void *packet_get_do(const struct pool *p, size_t idx, size_t offset,
 		return NULL;
 	}
 
-	if (len > PACKET_MAX_LEN) {
-		if (func) {
-			trace("packet data length %zu, %s:%i",
-			      len, func, line);
-		}
-		return NULL;
-	}
-
 	if (offset > p->pkt[idx].iov_len ||
 	    len > (p->pkt[idx].iov_len - offset)) {
 		if (func) {
-- 
@@ -35,6 +35,12 @@
 static int packet_check_range(const struct pool *p, const char *ptr, size_t len,
 			      const char *func, int line)
 {
+	if (len > PACKET_MAX_LEN) {
+		trace("packet range length %zu (max %zu), %s:%i",
+		      len, PACKET_MAX_LEN, func, line);
+		return -1;
+	}
+
 	if (p->buf_size == 0) {
 		int ret;
 
@@ -100,11 +106,6 @@ void packet_add_do(struct pool *p, size_t len, const char *start,
 	if (packet_check_range(p, start, len, func, line))
 		return;
 
-	if (len > PACKET_MAX_LEN) {
-		trace("add packet length %zu, %s:%i", len, func, line);
-		return;
-	}
-
 	p->pkt[idx].iov_base = (void *)start;
 	p->pkt[idx].iov_len = len;
 
@@ -136,14 +137,6 @@ void *packet_get_do(const struct pool *p, size_t idx, size_t offset,
 		return NULL;
 	}
 
-	if (len > PACKET_MAX_LEN) {
-		if (func) {
-			trace("packet data length %zu, %s:%i",
-			      len, func, line);
-		}
-		return NULL;
-	}
-
 	if (offset > p->pkt[idx].iov_len ||
 	    len > (p->pkt[idx].iov_len - offset)) {
 		if (func) {
-- 
2.48.1


  parent reply	other threads:[~2025-03-17 10:02 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-03-17  9:24 [PATCH v2 00/11] Improve robustness of calculations related to frame size limits David Gibson
2025-03-17  9:24 ` [PATCH v2 01/11] vu_common: Tighten vu_packet_check_range() David Gibson
2025-03-17  9:24 ` [PATCH v2 02/11] packet: More cautious checks to avoid pointer arithmetic UB David Gibson
2025-03-17  9:24 ` [PATCH v2 03/11] tap: Make size of pool_tap[46] purely a tuning parameter David Gibson
2025-03-17  9:24 ` [PATCH v2 04/11] tap: Clarify calculation of TAP_MSGS David Gibson
2025-03-17  9:24 ` [PATCH v2 05/11] packet: Correct type of PACKET_MAX_LEN David Gibson
2025-03-17  9:24 ` [PATCH v2 06/11] packet: Avoid integer overflows in packet_get_do() David Gibson
2025-03-17  9:24 ` David Gibson [this message]
2025-03-17  9:24 ` [PATCH v2 08/11] packet: Rework packet_get() versus packet_get_try() David Gibson
2025-03-17  9:24 ` [PATCH v2 09/11] util: Add abort_with_msg() and ASSERT_WITH_MSG() helpers David Gibson
2025-03-17  9:24 ` [PATCH v2 10/11] packet: ASSERT on signs of pool corruption David Gibson
2025-03-17  9:24 ` [PATCH v2 11/11] packet: Upgrade severity of most packet errors David Gibson

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