(nuttx) branch master updated: net: preserve checksum state for empty fragments

[xiaoxiang]

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xiaoxiang781216 pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/nuttx.git


The following commit(s) were added to refs/heads/master by this push:
     new 05cc04e306b net: preserve checksum state for empty fragments
05cc04e306b is described below

commit 05cc04e306b9fd8ddf898adb91a0a49f22c9789d
Author: Megha Rajput <i.meghar.2...@gmail.com>
AuthorDate: Thu Sep 3 16:11:30 2026 +0000

    net: preserve checksum state for empty fragments
    
    checksum() accesses data[0] and calculates an invalid last_byte
    pointer when processing an empty fragment with odd state set.
    
    Return early when len is zero to preserve the checksum state and
    avoid accessing data from an empty fragment.
    
    Assisted by: GitHub Copilot
    Signed-off-by: Megha Rajput <i.meghar.2...@gmail.com>
---
 net/utils/net_chksum.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/net/utils/net_chksum.c b/net/utils/net_chksum.c
index 169c4b7c1bf..6079a7d4e22 100644
--- a/net/utils/net_chksum.c
+++ b/net/utils/net_chksum.c
@@ -61,6 +61,11 @@ uint16_t checksum(uint16_t sum, FAR const uint8_t *data,
   FAR const uint8_t *last_byte;
   uint16_t t;
 
+  if (len == 0)
+    {
+      return sum;
+    }
+
   dataptr = data;
   last_byte = data + len - 1;