Maybe related: seems that the default for "mcheck" or MALLOC_CHECK_ has changed.
I observe an oddity. I only noticed this recently, with libc6 version 2.36-9+deb12u1; reverting to previous 2.36-9 did not seem to help. The issue. Sending SIGHUP to the inetd(8) process should cause it to re-load its configuration, but instead it elicits free(): double free detected in tcache 2 and an abort. This is easiest seen (after "systemctl stop inetd") with root# inetd -d -i & sleep 1; kill -HUP $!; sleep 1; jobs [1] 2431 ADD: ident proto=tcp4, wait.max=1.256 user:group=identd:(default) builtin=0 server=/usr/sbin/identd free(): double free detected in tcache 2 [1]+ Aborted inetd -d -i root# Sanity(?) is restored by using MALLOC_CHECK_=0 (needs LD_PRELOAD): root# LD_PRELOAD=libc_malloc_debug.so MALLOC_CHECK_=0 inetd -d -i & sleep 1; kill -HUP $!; sleep 1; jobs; kill $!; sleep 1; jobs [1] 2437 ADD: ident proto=tcp4, wait.max=1.256 user:group=identd:(default) builtin=0 server=/usr/sbin/identd REDO: ident proto=tcp4, wait.max=1.256 user:group=identd:(default) builtin=0 server=/usr/sbin/identd [1]+ Running LD_PRELOAD=libc_malloc_debug.so MALLOC_CHECK_=0 inetd -d -i & [1]+ Done LD_PRELOAD=libc_malloc_debug.so MALLOC_CHECK_=0 inetd -d -i root# To compound the oddity, the value of MALLOC_CHECK_ or even its presence seems ignored, just the LD_PRELOAD=libc_malloc_debug.so "fixes" the issue. Hope this helps to find the cause. Cheers, Paul References: http://btorpey.github.io/blog/2019/07/14/memory-checking/ https://www.gnu.org/software/libc/manual/html_node/Heap-Consistency-Checking.html -- Paul Szabo p...@maths.usyd.edu.au www.maths.usyd.edu.au/u/psz School of Mathematics and Statistics University of Sydney Australia Join the Union and fight for a better University: www.nteu.au/join
