In the Linux kernel, the following vulnerability has been resolved:
perf/core: Fix data race between perf_event_set_output() and perf_mmap_close()
Yang Jihing reported a race between perf_event_set_output() and
perf_mmap_close():
CPU1 CPU2
perf_mmap_close(e2)
if (atomic_dec_and_test(&e2->rb->mmap_count)) // 1 - > 0
detach_rest = true
ioctl(e1, IOC_SET_OUTPUT, e2)
perf_event_set_output(e1, e2)
...
list_for_each_entry_rcu(e, &e2->rb->event_list, rb_entry)
ring_buffer_attach(e, NULL);
// e1 isn't yet added and
// therefore not detached
ring_buffer_attach(e1, e2->rb)
list_add_rcu(&e1->rb_entry,
&e2->rb->event_list)
After this; e1 is attached to an unmapped rb and a subsequent
perf_mmap() will loop forever more:
again:
mutex_lock(&e->mmap_mutex);
if (event->rb) {
...
if (!atomic_inc_not_zero(&e->rb->mmap_count)) {
...
mutex_unlock(&e->mmap_mutex);
goto again;
}
}
The loop in perf_mmap_close() holds e2->mmap_mutex, while the attach
in perf_event_set_output() holds e1->mmap_mutex. As such there is no
serialization to avoid this race.
Change perf_event_set_output() to take both e1->mmap_mutex and
e2->mmap_mutex to alleviate that problem. Additionally, have the loop
in perf_mmap() detach the rb directly, this avoids having to wait for
the concurrent perf_mmap_close() to get around to doing it to make
progress.
In the Linux kernel, the following vulnerability has been resolved:
KVM: VMX: Prevent RSB underflow before vmenter
On VMX, there are some balanced returns between the time the guest's
SPEC_CTRL value is written, and the vmenter.
Balanced returns (matched by a preceding call) are usually ok, but it's
at least theoretically possible an NMI with a deep call stack could
empty the RSB before one of the returns.
For maximum paranoia, don't allow *any* returns (balanced or otherwise)
between the SPEC_CTRL write and the vmenter.
[ bp: Fix 32-bit build. ]
In the Linux kernel, the following vulnerability has been resolved:
x86/speculation: Fill RSB on vmexit for IBRS
Prevent RSB underflow/poisoning attacks with RSB. While at it, add a
bunch of comments to attempt to document the current state of tribal
knowledge about RSB attacks and what exactly is being mitigated.
In the Linux kernel, the following vulnerability has been resolved:
ASoC: rt711-sdca: fix kernel NULL pointer dereference when IO error
The initial settings will be written before the codec probe function.
But, the rt711->component doesn't be assigned yet.
If IO error happened during initial settings operations, it will cause the kernel panic.
This patch changed component->dev to slave->dev to fix this issue.
In the Linux kernel, the following vulnerability has been resolved:
tcp: Fix data-races around sysctl_tcp_base_mss.
While reading sysctl_tcp_base_mss, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its readers.
In the Linux kernel, the following vulnerability has been resolved:
tcp: Fix data-races around sysctl_tcp_mtu_probing.
While reading sysctl_tcp_mtu_probing, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its readers.
In the Linux kernel, the following vulnerability has been resolved:
tcp: Fix data-races around sysctl_tcp_fastopen.
While reading sysctl_tcp_fastopen, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its readers.
In the Linux kernel, the following vulnerability has been resolved:
tcp: Fix a data-race around sysctl_tcp_thin_linear_timeouts.
While reading sysctl_tcp_thin_linear_timeouts, it can be changed
concurrently. Thus, we need to add READ_ONCE() to its reader.
In the Linux kernel, the following vulnerability has been resolved:
crypto: qat - add param check for RSA
Reject requests with a source buffer that is bigger than the size of the
key. This is to prevent a possible integer underflow that might happen
when copying the source scatterlist into a linear buffer.