fix(mdns): Fix null pointer exception in mdns_parse_packet (IDFGH-17353)#1025
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scaiper wants to merge 1 commit intoespressif:masterfrom
Open
fix(mdns): Fix null pointer exception in mdns_parse_packet (IDFGH-17353)#1025scaiper wants to merge 1 commit intoespressif:masterfrom
scaiper wants to merge 1 commit intoespressif:masterfrom
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david-cermak
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Mar 13, 2026
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Hi @scaiper
Thank you for your contribution!
I briefly checked and it seems to be possible that the question list is NULL while nr of questions is non zero in the packet header (and even with valid packets!).
thanks again for the fix.
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Description
This PR fixes a null pointer exception in mdns component.
In
mdns_parse_packetfunction there is a call toremove_parsed_questionwhich might getparsed_packetwith the NULLquestionsfield.https://github.com/espressif/esp-protocols/blob/mdns-v1.10.1/components/mdns/mdns_receive.c#L860
There is the log of the crash. Backtrace points to the neighboring call, probably, due to compiler optimizations.
Related
All of my esphome devices running esp32 started crashing with this error after I updated my routers to OpenWrt 25.12.
I don't know, are mdns packets causing this issue valid or not. Regardless, mdns componets should not just crash.
Testing
Checklist
Before submitting a Pull Request, please ensure the following:
Note
Low Risk
Low risk: adds a simple NULL check to avoid dereferencing an empty questions list during mDNS packet parsing, with no behavioral change when questions are present.
Overview
Prevents a crash in
mdns_parse_packetby makingremove_parsed_questionreturn early whenparsed_packet->questionsisNULL, avoiding a null dereference inquestion_matchesfor packets that produce no saved questions.Written by Cursor Bugbot for commit 5681209. This will update automatically on new commits. Configure here.