kernel/linux.git/sound/core/seq/seq_ports.c, branch v6.3

ALSA: seq: replace ternary operator with max()

2022-05-17T06:49:42+00:00

Fix the following coccicheck warning: sound/core/seq/seq_ports.c:142:12-14: WARNING opportunity for max() Signed-off-by: Guo Zhengkui Link: https://lore.kernel.org/r/20220517062518.123292-1-guozhengkui@vivo.com Signed-off-by: Takashi Iwai

ALSA: seq: Fix racy deletion of subscriber

2021-08-03T11:43:40+00:00

It turned out that the current implementation of the port subscription is racy. The subscription contains two linked lists, and we have to add to or delete from both lists. Since both connection and disconnection procedures perform the same order for those two lists (i.e. src list, then dest list), when a deletion happens during a connection procedure, the src list may be deleted before the dest list addition completes, and this may lead to a use-after-free or an Oops, even though the access to both lists are protected via mutex. The simple workaround for this race is to change the access order for the disconnection, namely, dest list, then src list. This assures that the connection has been established when disconnecting, and also the concurrent deletion can be avoided. Reported-and-tested-by: folkert Cc: Link: https://lore.kernel.org/r/20210801182754.GP890690@belle.intranet.vanheusden.com Link: https://lore.kernel.org/r/20210803114312.2536-1-tiwai@suse.de Signed-off-by: Takashi Iwai

ALSA: Convert strlcpy to strscpy when return value is unused

2021-01-08T08:30:05+00:00

strlcpy is deprecated. see: Documentation/process/deprecated.rst Change the calls that do not use the strlcpy return value to the preferred strscpy. Done with cocci script: @@ expression e1, e2, e3; @@ - strlcpy( + strscpy( e1, e2, e3); This cocci script leaves the instances where the return value is used unchanged. After this patch, sound/ has 3 uses of strlcpy() that need to be manually inspected for conversion and changed one day. $ git grep -w strlcpy sound/ sound/usb/card.c: len = strlcpy(card->longname, s, sizeof(card->longname)); sound/usb/mixer.c: return strlcpy(buf, p->name, buflen); sound/usb/mixer.c: return strlcpy(buf, p->names[index], buflen); Miscellenea: o Remove trailing whitespace in conversion of sound/core/hwdep.c Link: https://lore.kernel.org/lkml/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/ Signed-off-by: Joe Perches Acked-by: Mark Brown Link: https://lore.kernel.org/r/22b393d1790bb268769d0bab7bacf0866dcb0c14.camel@perches.com Signed-off-by: Takashi Iwai

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156

2019-05-30T18:26:35+00:00

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1334 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Reviewed-by: Richard Fontana Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de Signed-off-by: Greg Kroah-Hartman

ALSA: seq: Cover unsubscribe_port() in list_mutex

2019-04-12T10:50:10+00:00

The call of unsubscribe_port() which manages the group count and module refcount from delete_and_unsubscribe_port() looks racy; it's not covered by the group list lock, and it's likely a cause of the reported unbalance at port deletion. Let's move the call inside the group list_mutex to plug the hole. Reported-by: syzbot+e4c8abb920efa77bace9@syzkaller.appspotmail.com Signed-off-by: Takashi Iwai

ALSA: seq: Fix race of get-subscription call vs port-delete ioctls

2019-04-09T16:54:13+00:00

The snd_seq_ioctl_get_subscription() retrieves the port subscriber information as a pointer, while the object isn't protected, hence it may be deleted before the actual reference. This race was spotted by syzkaller and may lead to a UAF. The fix is simply copying the data in the lookup function that performs in the rwsem to protect against the deletion. Reported-by: syzbot+9437020c82413d00222d@syzkaller.appspotmail.com Signed-off-by: Takashi Iwai

ALSA: seq: Remove superfluous irqsave flags

2019-04-09T15:22:46+00:00

spin_lock_irqsave() is used unnecessarily in various places in sequencer core code although it's pretty obvious that the context is sleepable. Remove irqsave and use the plain spin_lock_irq() in such places for simplicity. Signed-off-by: Takashi Iwai

ALSA: seq: fix spelling mistake "Unamed" -> "Unnamed"

2018-05-26T21:59:32+00:00

Trivial fix to spelling mistake in string Signed-off-by: Colin Ian King Signed-off-by: Takashi Iwai

ALSA: seq: Fix use-after-free at creating a port

2017-10-11T07:58:18+00:00

There is a potential race window opened at creating and deleting a port via ioctl, as spotted by fuzzing. snd_seq_create_port() creates a port object and returns its pointer, but it doesn't take the refcount, thus it can be deleted immediately by another thread. Meanwhile, snd_seq_ioctl_create_port() still calls the function snd_seq_system_client_ev_port_start() with the created port object that is being deleted, and this triggers use-after-free like: BUG: KASAN: use-after-free in snd_seq_ioctl_create_port+0x504/0x630 [snd_seq] at addr ffff8801f2241cb1 ============================================================================= BUG kmalloc-512 (Tainted: G B ): kasan: bad access detected ----------------------------------------------------------------------------- INFO: Allocated in snd_seq_create_port+0x94/0x9b0 [snd_seq] age=1 cpu=3 pid=4511 ___slab_alloc+0x425/0x460 __slab_alloc+0x20/0x40 kmem_cache_alloc_trace+0x150/0x190 snd_seq_create_port+0x94/0x9b0 [snd_seq] snd_seq_ioctl_create_port+0xd1/0x630 [snd_seq] snd_seq_do_ioctl+0x11c/0x190 [snd_seq] snd_seq_ioctl+0x40/0x80 [snd_seq] do_vfs_ioctl+0x54b/0xda0 SyS_ioctl+0x79/0x90 entry_SYSCALL_64_fastpath+0x16/0x75 INFO: Freed in port_delete+0x136/0x1a0 [snd_seq] age=1 cpu=2 pid=4717 __slab_free+0x204/0x310 kfree+0x15f/0x180 port_delete+0x136/0x1a0 [snd_seq] snd_seq_delete_port+0x235/0x350 [snd_seq] snd_seq_ioctl_delete_port+0xc8/0x180 [snd_seq] snd_seq_do_ioctl+0x11c/0x190 [snd_seq] snd_seq_ioctl+0x40/0x80 [snd_seq] do_vfs_ioctl+0x54b/0xda0 SyS_ioctl+0x79/0x90 entry_SYSCALL_64_fastpath+0x16/0x75 Call Trace: [] dump_stack+0x63/0x82 [] print_trailer+0xfb/0x160 [] object_err+0x34/0x40 [] kasan_report.part.2+0x223/0x520 [] ? snd_seq_ioctl_create_port+0x504/0x630 [snd_seq] [] __asan_report_load1_noabort+0x2e/0x30 [] snd_seq_ioctl_create_port+0x504/0x630 [snd_seq] [] ? snd_seq_ioctl_delete_port+0x180/0x180 [snd_seq] [] ? taskstats_exit+0xbc0/0xbc0 [] snd_seq_do_ioctl+0x11c/0x190 [snd_seq] [] snd_seq_ioctl+0x40/0x80 [snd_seq] [] ? acct_account_cputime+0x63/0x80 [] do_vfs_ioctl+0x54b/0xda0 ..... We may fix this in a few different ways, and in this patch, it's fixed simply by taking the refcount properly at snd_seq_create_port() and letting the caller unref the object after use. Also, there is another potential use-after-free by sprintf() call in snd_seq_create_port(), and this is moved inside the lock. This fix covers CVE-2017-15265. Reported-and-tested-by: Michael23 Yu Suggested-by: Linus Torvalds Cc: Signed-off-by: Takashi Iwai

ALSA: seq: Follow standard EXPORT_SYMBOL() declarations

2017-06-16T14:19:03+00:00

Just a tidy up to follow the standard EXPORT_SYMBOL*() declarations in order to improve grep-ability. - Move EXPORT_SYMBOL*() to the position right after its definition - Remove superfluous blank line before EXPORT_SYMBOL*() lines Signed-off-by: Takashi Iwai