Re: KMSAN: uninit-value in af_alg_free_areq_sgls

syzbot
2018-07-06T08:09:11Z

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