[66/67] msmouse: Fix segfault caused by free the chr before chardev cleanup.

Message ID 1481762701-4587-67-git-send-email-mdroth@linux.vnet.ibm.com
State New
Headers show

Commit Message

Michael Roth Dec. 15, 2016, 12:45 a.m.
From: Lin Ma <lma@suse.com>

Segfault happens when leaving qemu with msmouse backend:

 #0  0x00007fa8526ac975 in raise () at /lib64/libc.so.6
 #1  0x00007fa8526add8a in abort () at /lib64/libc.so.6
 #2  0x0000558be78846ab in error_exit (err=16, msg=0x558be799da10 ...
 #3  0x0000558be7884717 in qemu_mutex_destroy (mutex=0x558be93be750) at ...
 #4  0x0000558be7549951 in qemu_chr_free_common (chr=0x558be93be750) at ...
 #5  0x0000558be754999c in qemu_chr_free (chr=0x558be93be750) at ...
 #6  0x0000558be7549a20 in qemu_chr_delete (chr=0x558be93be750) at ...
 #7  0x0000558be754a8ef in qemu_chr_cleanup () at qemu-char.c:4643
 #8  0x0000558be755843e in main (argc=5, argv=0x7ffe925d7118, ...

The chr was freed by msmouse close callback before chardev cleanup,
Then qemu_mutex_destroy triggered raise().

Because freeing chr is handled by qemu_chr_free_common, Remove the free from
msmouse_chr_close to avoid double free.

Fixes: c1111a24a3358ecd2f17be7c8b117cfe8bc5e5f8
Cc: qemu-stable@nongnu.org
Signed-off-by: Lin Ma <lma@suse.com>
Message-Id: <20160915143158.4796-1-lma@suse.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 9e14037f05e99ca3b8a33d8be9a2a636bbf09326)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
 backends/msmouse.c | 1 -
 1 file changed, 1 deletion(-)


diff --git a/backends/msmouse.c b/backends/msmouse.c
index aceb6dc..85d08f7 100644
--- a/backends/msmouse.c
+++ b/backends/msmouse.c
@@ -139,7 +139,6 @@  static void msmouse_chr_close (struct CharDriverState *chr)
-    g_free(chr);
 static QemuInputHandler msmouse_handler = {