Qemu mode stuck at "[+] All right - fork server is up." about afl HOT 4 CLOSED

my guess is that you have triggered a qemu bug that is unrelated to afl, like a race condition in the ARM part, as otherwise this would have floated up much more often. And the afl qemu patches have nothing ARM specific. qemu 2.1 is really old ...
(btw if you fuzz a library with -Q you have to set AFL_INST_LIBS=1)
as a workaround you could use afl++'s qemu mode, it is 3.1 based and likely does not have this bug -> github.com/AFLplusplus/AFLplusplus

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Thank you very much for your reply, I will try AFLplusplus

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please always write which version you are using. is it a release - if yes which version? is it a git checkout - if yes which commit id?

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release 2.56b, my enviroment is Ubuntu 18.04.4

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