On Sun, 16 Jul 2023 at 22:47, Geraldo Nascimento <geraldogabriel@xxxxxxxxx> wrote: > > On Sun, Jul 16, 2023 at 03:07:23PM +0200, Takashi Iwai wrote: > > On Sun, 16 Jul 2023 10:21:49 +0200, > > syzbot wrote: > > > > > > Hello, > > > > > > syzbot found the following issue on: > > > > > > HEAD commit: 3f01e9fed845 Merge tag 'linux-watchdog-6.5-rc2' of git://w.. > > > git tree: upstream > > > console output: https://syzkaller.appspot.com/x/log.txt?x=14b07344a80000 > > > kernel config: https://syzkaller.appspot.com/x/.config?x=75da4f0a455bdbd3 > > > dashboard link: https://syzkaller.appspot.com/bug?extid=cf8e7fa4eeec59b3d485 > > > compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 > > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15877dc2a80000 > > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12905004a80000 > > > > > > Downloadable assets: > > > disk image: https://storage.googleapis.com/syzbot-assets/441fb7ea58b8/disk-3f01e9fe.raw.xz > > > vmlinux: https://storage.googleapis.com/syzbot-assets/8fa7790ba0c3/vmlinux-3f01e9fe.xz > > > kernel image: https://storage.googleapis.com/syzbot-assets/5e7a6471dadf/bzImage-3f01e9fe.xz > > > > > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > > > Reported-by: syzbot+cf8e7fa4eeec59b3d485@xxxxxxxxxxxxxxxxxxxxxxxxx > > > > > > Warning: Permanently added '10.128.1.1' (ED25519) to the list of known hosts. > > > executing program > > > executing program > > > BUG: memory leak > > > unreferenced object 0xffff888100877000 (size 512): > > > comm "syz-executor257", pid 5012, jiffies 4294941742 (age 12.790s) > > > hex dump (first 32 bytes): > > > 80 ff 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > > > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > > > backtrace: > > > [<ffffffff8154bf94>] kmalloc_trace+0x24/0x90 mm/slab_common.c:1076 > > > [<ffffffff83d29e28>] kmalloc include/linux/slab.h:582 [inline] > > > [<ffffffff83d29e28>] kzalloc include/linux/slab.h:703 [inline] > > > [<ffffffff83d29e28>] snd_seq_create_port+0x78/0x300 sound/core/seq/seq_ports.c:135 > > > [<ffffffff83d1f681>] snd_seq_ioctl_create_port+0xe1/0x2a0 sound/core/seq/seq_clientmgr.c:1324 > > > [<ffffffff83d20e5e>] snd_seq_ioctl+0x13e/0x290 sound/core/seq/seq_clientmgr.c:2327 > > > [<ffffffff81685173>] vfs_ioctl fs/ioctl.c:51 [inline] > > > [<ffffffff81685173>] __do_sys_ioctl fs/ioctl.c:870 [inline] > > > [<ffffffff81685173>] __se_sys_ioctl fs/ioctl.c:856 [inline] > > > [<ffffffff81685173>] __x64_sys_ioctl+0x103/0x140 fs/ioctl.c:856 > > > [<ffffffff84a77ff9>] do_syscall_x64 arch/x86/entry/common.c:50 [inline] > > > [<ffffffff84a77ff9>] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 > > > [<ffffffff84c0008b>] entry_SYSCALL_64_after_hwframe+0x63/0xcd > > > > > > BUG: memory leak > > > unreferenced object 0xffff888106742c00 (size 512): > > > comm "syz-executor257", pid 5013, jiffies 4294942276 (age 7.450s) > > > hex dump (first 32 bytes): > > > 80 ff 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > > > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > > > backtrace: > > > [<ffffffff8154bf94>] kmalloc_trace+0x24/0x90 mm/slab_common.c:1076 > > > [<ffffffff83d29e28>] kmalloc include/linux/slab.h:582 [inline] > > > [<ffffffff83d29e28>] kzalloc include/linux/slab.h:703 [inline] > > > [<ffffffff83d29e28>] snd_seq_create_port+0x78/0x300 sound/core/seq/seq_ports.c:135 > > > [<ffffffff83d1f681>] snd_seq_ioctl_create_port+0xe1/0x2a0 sound/core/seq/seq_clientmgr.c:1324 > > > [<ffffffff83d20e5e>] snd_seq_ioctl+0x13e/0x290 sound/core/seq/seq_clientmgr.c:2327 > > > [<ffffffff81685173>] vfs_ioctl fs/ioctl.c:51 [inline] > > > [<ffffffff81685173>] __do_sys_ioctl fs/ioctl.c:870 [inline] > > > [<ffffffff81685173>] __se_sys_ioctl fs/ioctl.c:856 [inline] > > > [<ffffffff81685173>] __x64_sys_ioctl+0x103/0x140 fs/ioctl.c:856 > > > [<ffffffff84a77ff9>] do_syscall_x64 arch/x86/entry/common.c:50 [inline] > > > [<ffffffff84a77ff9>] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 > > > [<ffffffff84c0008b>] entry_SYSCALL_64_after_hwframe+0x63/0xcd > > > > Likely a forgotten kfree() at the error path. > > The patch below should fix it. > > > > > > Takashi > > > > -- 8< -- > > From: Takashi Iwai <tiwai@xxxxxxx> > > Subject: [PATCH] ALSA: seq: Fix memory leak at error path in > > snd_seq_create_port() > > > > We forgot to release a newly allocated item at the error path in > > snd_seq_create_port(). This patch fixes it. > > Thanks for the clarification and quick proposed resolution Takashi. As > an ALSA novice these bots always stunt me, personally. I understand how > helpful they are however, even if cryptic. Hi Geraldo, What exactly is cryptic in the report? Is there anything that can be done to make it less cryptic? > But shouldn't this be reported to security? It's always prone to bad > stuff when we forget a kfree() > > Thanks, > Geraldo Nascimento > > > > > Reported-by: syzbot+cf8e7fa4eeec59b3d485@xxxxxxxxxxxxxxxxxxxxxxxxx > > Closes: https://lore.kernel.org/r/00000000000098ed3a0600965f89@xxxxxxxxxx > > Cc: <stable@xxxxxxxxxxxxxxx> > > Signed-off-by: Takashi Iwai <tiwai@xxxxxxx> > > --- > > sound/core/seq/seq_ports.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/sound/core/seq/seq_ports.c b/sound/core/seq/seq_ports.c > > index 9b80f8275026..f3f14ff0f80f 100644 > > --- a/sound/core/seq/seq_ports.c > > +++ b/sound/core/seq/seq_ports.c > > @@ -149,6 +149,7 @@ int snd_seq_create_port(struct snd_seq_client *client, int port, > > write_lock_irq(&client->ports_lock); > > list_for_each_entry(p, &client->ports_list_head, list) { > > if (p->addr.port == port) { > > + kfree(new_port); > > num = -EBUSY; > > goto unlock; > > } > > -- > > 2.35.3
