alsactl distributed as part of Fedora 40 got a SEGV:
# journalctl
...
May 17 00:55:58 dev64.localdomain kernel: alsactl[1923]: segfault at 28 ip 00005600705b3373 sp 00007ffd9712bef0 error 4 in alsactl[5600705af000+13000] likely on CPU 5 (core 8, socket 0)
...
As the following output of the debug session, card_free() tried a card
pointing NULL:
$ sudo coredumpctl debug alsactl
PID: 1923 (alsactl)
UID: 0 (root)
GID: 0 (root)
Signal: 11 (SEGV)
Timestamp: Fri 2024-05-17 00:55:58 JST (3h 34min ago)
Command Line: /usr/sbin/alsactl -s -n 19 -c -E ALSA_CONFIG_PATH=/etc/alsa/alsactl.conf --initfile=/lib/alsa/init/00main rdaemon
Executable: /usr/sbin/alsactl
Control Group: /system.slice/alsa-state.service
Unit: alsa-state.service
Slice: system.slice
Boot ID: 241b5a2ef86f4940bb3d340583c80d88
Machine ID: 437365709a8c488c9481ee4b6651c2ec
Hostname: dev64.localdomain
Storage: /var/lib/systemd/coredump/core.alsactl.0.241b5a2ef86f4940bb3d340583c80d88.1923.1715874958000000.zst (present)
Size on Disk: 81.7K
Package: alsa-utils/1.2.11-1.fc40
build-id: 3b6fec58b3566d666d6e9fd48e8fcf04f03f0152
Message: Process 1923 (alsactl) of user 0 dumped core.
Module libasound.so.2 from rpm alsa-lib-1.2.11-2.fc40.x86_64
Module alsactl from rpm alsa-utils-1.2.11-1.fc40.x86_64
Stack trace of thread 1923:
#0 0x00005600705b3373 card_free (alsactl + 0xa373)
#1 0x00005600705c0e54 state_daemon (alsactl + 0x17e54)
#2 0x00005600705b2339 main (alsactl + 0x9339)
#3 0x00007f4c0b9b7088 __libc_start_call_main (libc.so.6 + 0x2a088)
#4 0x00007f4c0b9b714b __libc_start_main_impl (libc.so.6 + 0x2a14b)
#5 0x00005600705b2df5 _start (alsactl + 0x9df5)
ELF object binary architecture: AMD x86-64
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Reading symbols from /usr/sbin/alsactl...
Reading symbols from /usr/lib/debug/usr/sbin/alsactl-1.2.11-1.fc40.x86_64.debug...
[New LWP 1923]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
Core was generated by `/usr/sbin/alsactl -s -n 19 -c -E ALSA_CONFIG_PATH=/etc/alsa/alsactl.conf --init'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0 free_list (list=0x20) at /usr/src/debug/alsa-utils-1.2.11-1.fc40.x86_64/alsactl/daemon.c:73
73 for (i = 0; i < list->size; i++)
(gdb) where
#0 free_list (list=0x20) at /usr/src/debug/alsa-utils-1.2.11-1.fc40.x86_64/alsactl/daemon.c:73
#1 card_free (card=card@entry=0x5600707455f0) at /usr/src/debug/alsa-utils-1.2.11-1.fc40.x86_64/alsactl/daemon.c:82
#2 0x00005600705c0e54 in state_daemon (file=file@entry=0x5600705c31a1 "/var/lib/alsa/asound.state", cardname=cardname@entry=0x0, period=period@entry=300,
pidfile=pidfile@entry=0x5600705c3170 "/var/run/alsactl.pid") at /usr/src/debug/alsa-utils-1.2.11-1.fc40.x86_64/alsactl/daemon.c:455
#3 0x00005600705b2339 in main (argc=<optimized out>, argv=<optimized out>) at /usr/src/debug/alsa-utils-1.2.11-1.fc40.x86_64/alsactl/alsactl.c:459
(gdb) list
68
69 static void free_list(struct id_list *list)
70 {
71 int i;
72
73 for (i = 0; i < list->size; i++)
74 free(list->list[i]);
75 free(list->list);
76 }
77
(gdb) up
#1 card_free (card=card@entry=0x5600707455f0) at /usr/src/debug/alsa-utils-1.2.11-1.fc40.x86_64/alsactl/daemon.c:82
82 free_list(&c->blacklist);
(gdb) p c
$1 = (struct card *) 0x0
(gdb)
Closes: https://github.com/alsa-project/alsa-utils/pull/267
Signed-off-by: Masatake YAMATO <yamato@redhat.com>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
The code releasing the each card object may access to NULL when a
bogus count is given. Add a NULL check just to make sure.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
For the plug-and-play hardware, like USB devices, it may be helpful
to manage the sound state periodically, before the devices are removed.
This change implements new commands 'daemon' and 'rdaemon' to save
the sound state in defined intervals when the sound controls are changed.
The udev rules can notify the daemon using the 'kill' or 'nrestore'
commands to rescan available cards in the system.
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
