lightningd/peer_control: initialize error pointer in handle_peer_spoke#9001
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ThomsenDrake wants to merge 1 commit intoElementsProject:masterfrom
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lightningd/peer_control: initialize error pointer in handle_peer_spoke#9001ThomsenDrake wants to merge 1 commit intoElementsProject:masterfrom
ThomsenDrake wants to merge 1 commit intoElementsProject:masterfrom
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The local variable `error` in handle_peer_spoke() is declared as a pointer type with no initialization. Several error paths jump to the `send_error` label where `error` is dereferenced (passed to tal_hex() and towire_connectd_peer_send_msg()). While sockpair() currently sets the `error` pointer via the output parameter on failure, the declaration should be initialized to NULL as a defensive measure and to avoid undefined behavior if code paths change. Fixes ElementsProject#8849
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Summary
Fixes #8849
The Bug
In
lightningd/peer_control.c, thehandle_peer_spoke()function declares a local pointer variableerrorwithout initialization:Several error paths jump to the
send_errorlabel whereerroris dereferenced — specifically passed total_hex(tmpctx, error)andtowire_connectd_peer_send_msg(). Iferroris not initialized before reachingsend_error, this is undefined behavior (likely a segfault).The affected
goto send_errorpaths are all onsockpair()failure:While
sockpair()currently does set theerrorpointer via its output parameter on failure, the uninitialized declaration is still undefined behavior and fragile against future code changes.The Fix
Initialize
errortoNULLat declaration:This is the minimal, defensive fix that prevents undefined behavior regardless of which path reaches
send_error.