Re: KMSAN: uninit-value in af_alg_free_areq_sgls

[syzbot <syzbot+9c251bdd09f83b92ba95@syzkaller.appspotmail.com>]

Hello,

syzbot tried to test the proposed patch but build/boot failed:

lost connection to test machine



[....] Starting enhanced syslogd: rsyslogd^[[?25l^[[?1c^[7^[[1G[^[[32m ok  
^[[39;49m^[8^[[?25h^[[?0c.
[....] Starting periodic command scheduler: cron^[[?25l^[[?1c^[7^[[1G[^[[32m ok  
^[[39;49m^[8^[[?25h^[[?0c.
[....] Starting OpenBSD Secure Shell server: sshd[   21.709280] random:  
sshd: uninitialized urandom read (32 bytes read)
^[[?25l^[[?1c^[7^[[1G[^[[32m ok ^[[39;49m^[8^[[?25h^[[?0c.

Debian GNU/Linux 7 syzkaller ttyS0

syzkaller login: [   26.229113] random: sshd: uninitialized urandom read  
(32 bytes read)
[   26.532843] random: sshd: uninitialized urandom read (32 bytes read)
[   27.787277] random: sshd: uninitialized urandom read (32 bytes read)
Warning: Permanently added '10.128.0.2' (ECDSA) to the list of known hosts.
[   33.299368] random: sshd: uninitialized urandom read (32 bytes read)
flag provided but not defined: -os
Usage of ./syz-fuzzer:
   -abort_signal int
     	initial signal to send to executor in error conditions; upgrades to  
SIGKILL if executor does not exit
   -arch string
     	target arch (default "amd64")
   -buffer_size uint
     	internal buffer size (in bytes) for executor output
   -collide
     	collide syscalls to provoke data races (default true)
   -cover
     	collect feedback signals (coverage)
   -debug
     	debug output from executor
   -executor string
     	path to executor binary (default "./syz-executor")
   -ipc string
     	ipc scheme (pipe/shmem)
   -leak
     	detect memory leaks
   -manager string
     	manager rpc address
   -name string
     	unique name for manager (default "test")
   -output string
     	write programs to none/stdout/dmesg/file (default "stdout")
   -pprof string
     	address to serve pprof profiles
   -procs int
     	number of parallel test processes (default 1)
   -sandbox string
     	sandbox for fuzzing (none/setuid/namespace) (default "none")
   -test
     	enable image testing mode
   -threaded
     	use threaded mode in executor (default true)
   -timeout duration
     	execution timeout
   -v int
     	verbosity



Tested on:

commit:         9c9df9f275f0 kmsan: remove kmsan_threads_ready
git tree:       https://github.com/google/kmsan.git/master
kernel config:  https://syzkaller.appspot.com/x/.config?x=b11f4cfb262ee607
compiler:       clang version 7.0.0 (trunk 334104)
patch:          https://syzkaller.appspot.com/x/patch.diff?x=16a5af84400000