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[Qemu-block] [PATCH] block/ssh: Avoid segfault if inet_connect doesn't s
From: |
Richard W.M. Jones |
Subject: |
[Qemu-block] [PATCH] block/ssh: Avoid segfault if inet_connect doesn't set errno. |
Date: |
Wed, 22 Jul 2015 13:07:53 +0100 |
On some (but not all) systems:
$ qemu-img create -f qcow2 overlay -b ssh://xen/
Segmentation fault
It turns out this happens when inet_connect returns NULL in the
following code, but errno is not set (0).
s->sock = inet_connect(s->hostport, errp);
if (s->sock < 0) {
ret = -errno;
goto err;
}
In the case above, 'xen' doesn't exist so getaddrinfo fails. On
Fedora 22, getaddrinfo happens to set errno = ENOENT (although it is
_not_ documented to do that), so it doesn't segfault.
On RHEL 7, errno is not set by the failing getaddrinfo, so ret == 0,
so the caller doesn't know there was an error and continues with a
half-initialized BDRVSSHState struct, and everything goes south from
there.
Fix this by setting errno to EINVAL. The real error is saved in the
Error** errp struct, so it is printed correctly:
$ ./qemu-img create -f qcow2 overlay -b ssh://xen/
qemu-img: overlay: address resolution failed for xen:22: No address
associated with hostname
BZ: https://bugzilla.redhat.com/show_bug.cgi?id=1147343
Signed-off-by: Richard W.M. Jones <address@hidden>
---
block/ssh.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/block/ssh.c b/block/ssh.c
index aebb18c..8d4dc2a 100644
--- a/block/ssh.c
+++ b/block/ssh.c
@@ -563,7 +563,7 @@ static int connect_to_ssh(BDRVSSHState *s, QDict *options,
/* Open the socket and connect. */
s->sock = inet_connect(s->hostport, errp);
if (s->sock < 0) {
- ret = -errno;
+ ret = -EINVAL;
goto err;
}
--
2.4.3
- [Qemu-block] [PATCH] block/ssh: Avoid segfault if inet_connect doesn't set errno.,
Richard W.M. Jones <=