kernel/linux.git, branch v4.19.107

Linux 4.19.107

2020-02-28T15:39:01+00:00

Revert "char/random: silence a lockdep splat with printk()"

2020-02-28T15:39:00+00:00

This reverts commit 15341b1dd409749fa5625e4b632013b6ba81609b which is commit 1b710b1b10eff9d46666064ea25f079f70bc67a8 upstream. Lech writes: After upgrading kernel on our boards from v4.19.105 to v4.19.106 we found out that syslog fails to read the messages after ones read initially after opening /proc/kmsg just after booting. I also found out, that output of 'dmesg --follow' also doesn't react on new printks appearing for whatever reason - to read new messages, reopening /proc/kmsg or /dev/kmsg was needed. I bisected this down to commit 15341b1dd409749fa5625e4b632013b6ba81609b ("char/random: silence a lockdep splat with printk()"), and reverting it on top of v4.19.106 restored correct behaviour. While people dig to find out how such an odd change causes a lockup, let's just revert this for now as it's not all that big of a deal for 4.19.y. Reported-by: Lech Perczak Signed-off-by: Greg Kroah-Hartman Cc: Sergey Senozhatsky Cc: Qian Cai Cc: Theodore Ts'o Cc: Sasha Levin Cc: Petr Mladek Cc: John Ogness Signed-off-by: Greg Kroah-Hartman

s390/mm: Explicitly compare PAGE_DEFAULT_KEY against zero in storage_key_init_range

2020-02-28T15:39:00+00:00

commit 380324734956c64cd060e1db4304f3117ac15809 upstream. Clang warns: In file included from ../arch/s390/purgatory/purgatory.c:10: In file included from ../include/linux/kexec.h:18: In file included from ../include/linux/crash_core.h:6: In file included from ../include/linux/elfcore.h:5: In file included from ../include/linux/user.h:1: In file included from ../arch/s390/include/asm/user.h:11: ../arch/s390/include/asm/page.h:45:6: warning: converting the result of '<<' to a boolean always evaluates to false [-Wtautological-constant-compare] if (PAGE_DEFAULT_KEY) ^ ../arch/s390/include/asm/page.h:23:44: note: expanded from macro 'PAGE_DEFAULT_KEY' #define PAGE_DEFAULT_KEY (PAGE_DEFAULT_ACC << 4) ^ 1 warning generated. Explicitly compare this against zero to silence the warning as it is intended to be used in a boolean context. Fixes: de3fa841e429 ("s390/mm: fix compile for PAGE_DEFAULT_KEY != 0") Link: https://github.com/ClangBuiltLinux/linux/issues/860 Link: https://lkml.kernel.org/r/20200214064207.10381-1-natechancellor@gmail.com Acked-by: Christian Borntraeger Signed-off-by: Nathan Chancellor Signed-off-by: Vasily Gorbik Signed-off-by: Greg Kroah-Hartman

xen: Enable interrupts when calling _cond_resched()

2020-02-28T15:39:00+00:00

commit 8645e56a4ad6dcbf504872db7f14a2f67db88ef2 upstream. xen_maybe_preempt_hcall() is called from the exception entry point xen_do_hypervisor_callback with interrupts disabled. _cond_resched() evades the might_sleep() check in cond_resched() which would have caught that and schedule_debug() unfortunately lacks a check for irqs_disabled(). Enable interrupts around the call and use cond_resched() to catch future issues. Fixes: fdfd811ddde3 ("x86/xen: allow privcmd hypercalls to be preempted") Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/878skypjrh.fsf@nanos.tec.linutronix.de Reviewed-by: Juergen Gross Signed-off-by: Boris Ostrovsky Signed-off-by: Greg Kroah-Hartman

ata: ahci: Add shutdown to freeze hardware resources of ahci

2020-02-28T15:39:00+00:00

commit 10a663a1b15134a5a714aa515e11425a44d4fdf7 upstream. device_shutdown() called from reboot or power_shutdown expect all devices to be shutdown. Same is true for even ahci pci driver. As no ahci shutdown function is implemented, the ata subsystem always remains alive with DMA & interrupt support. File system related calls should not be honored after device_shutdown(). So defining ahci pci driver shutdown to freeze hardware (mask interrupt, stop DMA engine and free DMA resources). Signed-off-by: Prabhakar Kushwaha Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

rxrpc: Fix call RCU cleanup using non-bh-safe locks

2020-02-28T15:39:00+00:00

commit 963485d436ccc2810177a7b08af22336ec2af67b upstream. rxrpc_rcu_destroy_call(), which is called as an RCU callback to clean up a put call, calls rxrpc_put_connection() which, deep in its bowels, takes a number of spinlocks in a non-BH-safe way, including rxrpc_conn_id_lock and local->client_conns_lock. RCU callbacks, however, are normally called from softirq context, which can cause lockdep to notice the locking inconsistency. To get lockdep to detect this, it's necessary to have the connection cleaned up on the put at the end of the last of its calls, though normally the clean up is deferred. This can be induced, however, by starting a call on an AF_RXRPC socket and then closing the socket without reading the reply. Fix this by having rxrpc_rcu_destroy_call() punt the destruction to a workqueue if in softirq-mode and defer the destruction to process context. Note that another way to fix this could be to add a bunch of bh-disable annotations to the spinlocks concerned - and there might be more than just those two - but that means spending more time with BHs disabled. Note also that some of these places were covered by bh-disable spinlocks belonging to the rxrpc_transport object, but these got removed without the _bh annotation being retained on the next lock in. Fixes: 999b69f89241 ("rxrpc: Kill the client connection bundle concept") Reported-by: syzbot+d82f3ac8d87e7ccbb2c9@syzkaller.appspotmail.com Reported-by: syzbot+3f1fd6b8cbf8702d134e@syzkaller.appspotmail.com Signed-off-by: David Howells cc: Hillf Danton Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

netfilter: xt_hashlimit: limit the max size of hashtable

2020-02-28T15:39:00+00:00

commit 8d0015a7ab76b8b1e89a3e5f5710a6e5103f2dd5 upstream. The user-specified hashtable size is unbound, this could easily lead to an OOM or a hung task as we hold the global mutex while allocating and initializing the new hashtable. Add a max value to cap both cfg->size and cfg->max, as suggested by Florian. Reported-and-tested-by: syzbot+adf6c6c2be1c3a718121@syzkaller.appspotmail.com Signed-off-by: Cong Wang Reviewed-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman

ALSA: seq: Fix concurrent access to queue current tick/time

2020-02-28T15:39:00+00:00

commit dc7497795e014d84699c3b8809ed6df35352dd74 upstream. snd_seq_check_queue() passes the current tick and time of the given queue as a pointer to snd_seq_prioq_cell_out(), but those might be updated concurrently by the seq timer update. Fix it by retrieving the current tick and time via the proper helper functions at first, and pass those values to snd_seq_prioq_cell_out() later in the loops. snd_seq_timer_get_cur_time() takes a new argument and adjusts with the current system time only when it's requested so; this update isn't needed for snd_seq_check_queue(), as it's called either from the interrupt handler or right after queuing. Also, snd_seq_timer_get_cur_tick() is changed to read the value in the spinlock for the concurrency, too. Reported-by: syzbot+fd5e0eaa1a32999173b2@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/20200214111316.26939-3-tiwai@suse.de Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman

ALSA: seq: Avoid concurrent access to queue flags

2020-02-28T15:39:00+00:00

commit bb51e669fa49feb5904f452b2991b240ef31bc97 upstream. The queue flags are represented in bit fields and the concurrent access may result in unexpected results. Although the current code should be mostly OK as it's only reading a field while writing other fields as KCSAN reported, it's safer to cover both with a proper spinlock protection. This patch fixes the possible concurrent read by protecting with q->owner_lock. Also the queue owner field is protected as well since it's the field to be protected by the lock itself. Reported-by: syzbot+65c6c92d04304d0a8efc@syzkaller.appspotmail.com Reported-by: syzbot+e60ddfa48717579799dd@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/20200214111316.26939-2-tiwai@suse.de Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman

ALSA: rawmidi: Avoid bit fields for state flags

2020-02-28T15:38:59+00:00

commit dfa9a5efe8b932a84b3b319250aa3ac60c20f876 upstream. The rawmidi state flags (opened, append, active_sensing) are stored in bit fields that can be potentially racy when concurrently accessed without any locks. Although the current code should be fine, there is also no any real benefit by keeping the bitfields for this kind of short number of members. This patch changes those bit fields flags to the simple bool fields. There should be no size increase of the snd_rawmidi_substream by this change. Reported-by: syzbot+576cc007eb9f2c968200@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/20200214111316.26939-4-tiwai@suse.de Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman