From 949055a2549afc4cde06b7972072c7288bb43722 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= Date: Mon, 3 Oct 2016 13:47:04 +0400 Subject: char: use a fixed idx for child muxed chr MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit mux_chr_update_read_handler() is adding a new mux_cnt each time mux_chr_update_read_handler() is called, it's not possible to actually update the "child" chr callbacks that were set previously. This may lead to crashes if the "child" chr is destroyed: valgrind x86_64-softmmu/qemu-system-x86_64 -chardev stdio,mux=on,id=char0 -mon chardev=char0,mode=control,default when quitting: ==4306== Invalid read of size 8 ==4306== at 0x8061D3: json_lexer_destroy (json-lexer.c:385) ==4306== by 0x7E39F8: json_message_parser_destroy (json-streamer.c:134) ==4306== by 0x3447F6: monitor_qmp_event (monitor.c:3908) ==4306== by 0x480153: mux_chr_send_event (qemu-char.c:630) ==4306== by 0x480694: mux_chr_event (qemu-char.c:734) ==4306== by 0x47F1E9: qemu_chr_be_event (qemu-char.c:205) ==4306== by 0x481207: fd_chr_close (qemu-char.c:1114) ==4306== by 0x481659: qemu_chr_close_stdio (qemu-char.c:1221) ==4306== by 0x486F07: qemu_chr_free (qemu-char.c:4146) ==4306== by 0x486F97: qemu_chr_delete (qemu-char.c:4154) ==4306== by 0x487E66: qemu_chr_cleanup (qemu-char.c:4678) ==4306== by 0x495A98: main (vl.c:4675) ==4306== Address 0x28439e90 is 112 bytes inside a block of size 240 free'd ==4306== at 0x4C2CD5A: free (vg_replace_malloc.c:530) ==4306== by 0x1E4CBF2D: g_free (in /usr/lib64/libglib-2.0.so.0.4800.2) ==4306== by 0x344DE9: monitor_cleanup (monitor.c:4058) ==4306== by 0x495A93: main (vl.c:4674) ==4306== Block was alloc'd at ==4306== at 0x4C2BBAD: malloc (vg_replace_malloc.c:299) ==4306== by 0x1E4CBE18: g_malloc (in /usr/lib64/libglib-2.0.so.0.4800.2) ==4306== by 0x344BF8: monitor_init (monitor.c:4021) ==4306== by 0x49063C: mon_init_func (vl.c:2417) ==4306== by 0x7FC6DE: qemu_opts_foreach (qemu-option.c:1116) ==4306== by 0x4954E0: main (vl.c:4473) Instead, keep the "child" chr associated with a particular idx so its handlers can be updated and removed to avoid the crash. Signed-off-by: Marc-André Lureau Message-Id: <20161003094704.18087-3-marcandre.lureau@redhat.com> Signed-off-by: Paolo Bonzini --- include/sysemu/char.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/sysemu/char.h') diff --git a/include/sysemu/char.h b/include/sysemu/char.h index 0d0465ae0e..4593576cf7 100644 --- a/include/sysemu/char.h +++ b/include/sysemu/char.h @@ -92,6 +92,7 @@ struct CharDriverState { int explicit_be_open; int avail_connections; int is_mux; + int mux_idx; guint fd_in_tag; QemuOpts *opts; bool replay; -- cgit v1.2.3