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commit bddac7c1e02ba47f0570e494c9289acea3062cc1 upstream.
This reverts commit aa6f8dcbab473f3a3c7454b74caa46d36cdc5d13.
It turns out this breaks at least the ath9k wireless driver, and
possibly others.
What the ath9k driver does on packet receive is to set up the DMA
transfer with:
int ath_rx_init(..)
..
bf->bf_buf_addr = dma_map_single(sc->dev, skb->data,
common->rx_bufsize,
DMA_FROM_DEVICE);
and then the receive logic (through ath_rx_tasklet()) will fetch
incoming packets
static bool ath_edma_get_buffers(..)
..
dma_sync_single_for_cpu(sc->dev, bf->bf_buf_addr,
common->rx_bufsize, DMA_FROM_DEVICE);
ret = ath9k_hw_process_rxdesc_edma(ah, rs, skb->data);
if (ret == -EINPROGRESS) {
/*let device gain the buffer again*/
dma_sync_single_for_device(sc->dev, bf->bf_buf_addr,
common->rx_bufsize, DMA_FROM_DEVICE);
return false;
}
and it's worth noting how that first DMA sync:
dma_sync_single_for_cpu(..DMA_FROM_DEVICE);
is there to make sure the CPU can read the DMA buffer (possibly by
copying it from the bounce buffer area, or by doing some cache flush).
The iommu correctly turns that into a "copy from bounce bufer" so that
the driver can look at the state of the packets.
In the meantime, the device may continue to write to the DMA buffer, but
we at least have a snapshot of the state due to that first DMA sync.
But that _second_ DMA sync:
dma_sync_single_for_device(..DMA_FROM_DEVICE);
is telling the DMA mapping that the CPU wasn't interested in the area
because the packet wasn't there. In the case of a DMA bounce buffer,
that is a no-op.
Note how it's not a sync for the CPU (the "for_device()" part), and it's
not a sync for data written by the CPU (the "DMA_FROM_DEVICE" part).
Or rather, it _should_ be a no-op. That's what commit aa6f8dcbab47
broke: it made the code bounce the buffer unconditionally, and changed
the DMA_FROM_DEVICE to just unconditionally and illogically be
DMA_TO_DEVICE.
[ Side note: purely within the confines of the swiotlb driver it wasn't
entirely illogical: The reason it did that odd DMA_FROM_DEVICE ->
DMA_TO_DEVICE conversion thing is because inside the swiotlb driver,
it uses just a swiotlb_bounce() helper that doesn't care about the
whole distinction of who the sync is for - only which direction to
bounce.
So it took the "sync for device" to mean that the CPU must have been
the one writing, and thought it meant DMA_TO_DEVICE. ]
Also note how the commentary in that commit was wrong, probably due to
that whole confusion, claiming that the commit makes the swiotlb code
"bounce unconditionally (that is, also
when dir == DMA_TO_DEVICE) in order do avoid synchronising back stale
data from the swiotlb buffer"
which is nonsensical for two reasons:
- that "also when dir == DMA_TO_DEVICE" is nonsensical, as that was
exactly when it always did - and should do - the bounce.
- since this is a sync for the device (not for the CPU), we're clearly
fundamentally not coping back stale data from the bounce buffers at
all, because we'd be copying *to* the bounce buffers.
So that commit was just very confused. It confused the direction of the
synchronization (to the device, not the cpu) with the direction of the
DMA (from the device).
Reported-and-bisected-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Reported-by: Olha Cherevyk <olha.cherevyk@gmail.com>
Cc: Halil Pasic <pasic@linux.ibm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Kalle Valo <kvalo@kernel.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Toke Høiland-Jørgensen <toke@toke.dk>
Cc: Maxime Bizon <mbizon@freebox.fr>
Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 10c535787436d62ea28156a4b91365fd89b5a432 upstream.
Currently rcu_preempt_deferred_qs_irqrestore() releases rnp->boost_mtx
before reporting the expedited quiescent state. Under heavy real-time
load, this can result in this function being preempted before the
quiescent state is reported, which can in turn prevent the expedited grace
period from completing. Tim Murray reports that the resulting expedited
grace periods can take hundreds of milliseconds and even more than one
second, when they should normally complete in less than a millisecond.
This was fine given that there were no particular response-time
constraints for synchronize_rcu_expedited(), as it was designed
for throughput rather than latency. However, some users now need
sub-100-millisecond response-time constratints.
This patch therefore follows Neeraj's suggestion (seconded by Tim and
by Uladzislau Rezki) of simply reversing the two operations.
Reported-by: Tim Murray <timmurray@google.com>
Reported-by: Joel Fernandes <joelaf@google.com>
Reported-by: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Reviewed-by: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Tested-by: Tim Murray <timmurray@google.com>
Cc: Todd Kjos <tkjos@google.com>
Cc: Sandeep Patil <sspatil@google.com>
Cc: <stable@vger.kernel.org> # 5.4.x
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 4edc0760412b0c4ecefc7e02cb855b310b122825 upstream.
watch_queue_clear() has a comment stating that setting ->defunct to true
preventing new additions as well as preventing notifications. Whilst
the latter is true, the first bit is superfluous since at the time this
function is called, the pipe cannot be accessed to add new event
sources.
Remove the "new additions" bit from the comment.
Fixes: c73be61cede5 ("pipe: Add general notification queue support")
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 2ed147f015af2b48f41c6f0b6746aa9ea85c19f3 upstream.
There's nothing to synchronise post_one_notification() versus
pipe_read(). Whilst posting is done under pipe->rd_wait.lock, the
reader only takes pipe->mutex which cannot bar notification posting as
that may need to be made from contexts that cannot sleep.
Fix this by setting pipe->head with a barrier in post_one_notification()
and reading pipe->head with a barrier in pipe_read().
If that's not sufficient, the rd_wait.lock will need to be taken,
possibly in a ->confirm() op so that it only applies to notifications.
The lock would, however, have to be dropped before copy_page_to_iter()
is invoked.
Fixes: c73be61cede5 ("pipe: Add general notification queue support")
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 7ea1a0124b6da246b5bc8c66cddaafd36acf3ecb upstream.
Free the watch_queue note allocation bitmap when the watch_queue is
destroyed.
Fixes: c73be61cede5 ("pipe: Add general notification queue support")
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 3b4c0371928c17af03e8397ac842346624017ce6 upstream.
Currently, watch_queue_set_size() sets the number of notes available in
wqueue->nr_notes according to the number of notes allocated, but sets
the size of the bitmap to the unrounded number of notes originally asked
for.
Fix this by setting the bitmap size to the number of notes we're
actually going to make available (ie. the number allocated).
Fixes: c73be61cede5 ("pipe: Add general notification queue support")
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 96a4d8912b28451cd62825fd7caa0e66e091d938 upstream.
The pipe ring size must always be a power of 2 as the head and tail
pointers are masked off by AND'ing with the size of the ring - 1.
watch_queue_set_size(), however, lets you specify any number of notes
between 1 and 511. This number is passed through to pipe_resize_ring()
without checking/forcing its alignment.
Fix this by rounding the number of slots required up to the nearest
power of two. The request is meant to guarantee that at least that many
notifications can be generated before the queue is full, so rounding
down isn't an option, but, alternatively, it may be better to give an
error if we aren't allowed to allocate that much ring space.
Fixes: c73be61cede5 ("pipe: Add general notification queue support")
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit c1853fbadcba1497f4907971e7107888e0714c81 upstream.
When a pipe ring descriptor points to a notification message, the
refcount on the backing page is incremented by the generic get function,
but the release function, which marks the bitmap, doesn't drop the page
ref.
Fix this by calling generic_pipe_buf_release() at the end of
watch_queue_pipe_buf_release().
Fixes: c73be61cede5 ("pipe: Add general notification queue support")
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit c993ee0f9f81caf5767a50d1faeba39a0dc82af2 upstream.
In watch_queue_set_filter(), there are a couple of places where we check
that the filter type value does not exceed what the type_filter bitmap
can hold. One place calculates the number of bits by:
if (tf[i].type >= sizeof(wfilter->type_filter) * 8)
which is fine, but the second does:
if (tf[i].type >= sizeof(wfilter->type_filter) * BITS_PER_LONG)
which is not. This can lead to a couple of out-of-bounds writes due to
a too-large type:
(1) __set_bit() on wfilter->type_filter
(2) Writing more elements in wfilter->filters[] than we allocated.
Fix this by just using the proper WATCH_TYPE__NR instead, which is the
number of types we actually know about.
The bug may cause an oops looking something like:
BUG: KASAN: slab-out-of-bounds in watch_queue_set_filter+0x659/0x740
Write of size 4 at addr ffff88800d2c66bc by task watch_queue_oob/611
...
Call Trace:
<TASK>
dump_stack_lvl+0x45/0x59
print_address_description.constprop.0+0x1f/0x150
...
kasan_report.cold+0x7f/0x11b
...
watch_queue_set_filter+0x659/0x740
...
__x64_sys_ioctl+0x127/0x190
do_syscall_64+0x43/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
Allocated by task 611:
kasan_save_stack+0x1e/0x40
__kasan_kmalloc+0x81/0xa0
watch_queue_set_filter+0x23a/0x740
__x64_sys_ioctl+0x127/0x190
do_syscall_64+0x43/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
The buggy address belongs to the object at ffff88800d2c66a0
which belongs to the cache kmalloc-32 of size 32
The buggy address is located 28 bytes inside of
32-byte region [ffff88800d2c66a0, ffff88800d2c66c0)
Fixes: c73be61cede5 ("pipe: Add general notification queue support")
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit aa6f8dcbab473f3a3c7454b74caa46d36cdc5d13 upstream.
Unfortunately, we ended up merging an old version of the patch "fix info
leak with DMA_FROM_DEVICE" instead of merging the latest one. Christoph
(the swiotlb maintainer), he asked me to create an incremental fix
(after I have pointed this out the mix up, and asked him for guidance).
So here we go.
The main differences between what we got and what was agreed are:
* swiotlb_sync_single_for_device is also required to do an extra bounce
* We decided not to introduce DMA_ATTR_OVERWRITE until we have exploiters
* The implantation of DMA_ATTR_OVERWRITE is flawed: DMA_ATTR_OVERWRITE
must take precedence over DMA_ATTR_SKIP_CPU_SYNC
Thus this patch removes DMA_ATTR_OVERWRITE, and makes
swiotlb_sync_single_for_device() bounce unconditionally (that is, also
when dir == DMA_TO_DEVICE) in order do avoid synchronising back stale
data from the swiotlb buffer.
Let me note, that if the size used with dma_sync_* API is less than the
size used with dma_[un]map_*, under certain circumstances we may still
end up with swiotlb not being transparent. In that sense, this is no
perfect fix either.
To get this bullet proof, we would have to bounce the entire
mapping/bounce buffer. For that we would have to figure out the starting
address, and the size of the mapping in
swiotlb_sync_single_for_device(). While this does seem possible, there
seems to be no firm consensus on how things are supposed to work.
Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Fixes: ddbd89deb7d3 ("swiotlb: fix info leak with DMA_FROM_DEVICE")
Cc: stable@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit caf4c86bf136845982c5103b2661751b40c474c0 upstream.
At the moment running osnoise on a nohz_full CPU or uncontested FIFO
priority and a PREEMPT_RCU kernel might have the side effect of
extending grace periods too much. This will entice RCU to force a
context switch on the wayward CPU to end the grace period, all while
introducing unwarranted noise into the tracer. This behaviour is
unavoidable as overly extending grace periods might exhaust the system's
memory.
This same exact problem is what extended quiescent states (EQS) were
created for, conversely, rcu_momentary_dyntick_idle() emulates them by
performing a zero duration EQS. So let's make use of it.
In the common case rcu_momentary_dyntick_idle() is fairly inexpensive:
atomically incrementing a local per-CPU counter and doing a store. So it
shouldn't affect osnoise's measurements (which has a 1us granularity),
so we'll call it unanimously.
The uncommon case involve calling rcu_momentary_dyntick_idle() after
having the osnoise process:
- Receive an expedited quiescent state IPI with preemption disabled or
during an RCU critical section. (activates rdp->cpu_no_qs.b.exp
code-path).
- Being preempted within in an RCU critical section and having the
subsequent outermost rcu_read_unlock() called with interrupts
disabled. (t->rcu_read_unlock_special.b.blocked code-path).
Neither of those are possible at the moment, and are unlikely to be in
the future given the osnoise's loop design. On top of this, the noise
generated by the situations described above is unavoidable, and if not
exposed by rcu_momentary_dyntick_idle() will be eventually seen in
subsequent rcu_read_unlock() calls or schedule operations.
Link: https://lkml.kernel.org/r/20220307180740.577607-1-nsaenzju@redhat.com
Cc: stable@vger.kernel.org
Fixes: bce29ac9ce0b ("trace: Add osnoise tracer")
Signed-off-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit dd990352f01ee9a6c6eee152e5d11c021caccfe4 ]
osnoise's runtime and period are in the microseconds scale, but it is
currently sleeping in the millisecond's scale. This behavior roots in the
usage of hwlat as the skeleton for osnoise.
Make osnoise to sleep in the microseconds scale. Also, move the sleep to
a specialized function.
Link: https://lkml.kernel.org/r/302aa6c7bdf2d131719b22901905e9da122a11b2.1645197336.git.bristot@kernel.org
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 7acf3a127bb7c65ff39099afd78960e77b2ca5de ]
Booting the kernel with 'trace_buf_size=1' give a warning at
boot during the ftrace selftests:
[ 0.892809] Running postponed tracer tests:
[ 0.892893] Testing tracer function:
[ 0.901899] Callback from call_rcu_tasks_trace() invoked.
[ 0.983829] Callback from call_rcu_tasks_rude() invoked.
[ 1.072003] .. bad ring buffer .. corrupted trace buffer ..
[ 1.091944] Callback from call_rcu_tasks() invoked.
[ 1.097695] PASSED
[ 1.097701] Testing dynamic ftrace: .. filter failed count=0 ..FAILED!
[ 1.353474] ------------[ cut here ]------------
[ 1.353478] WARNING: CPU: 0 PID: 1 at kernel/trace/trace.c:1951 run_tracer_selftest+0x13c/0x1b0
Therefore enforce a minimum of 4096 bytes to make the selftest pass.
Link: https://lkml.kernel.org/r/20220214134456.1751749-1-svens@linux.ibm.com
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit ddbd89deb7d32b1fbb879f48d68fda1a8ac58e8e ]
The problem I'm addressing was discovered by the LTP test covering
cve-2018-1000204.
A short description of what happens follows:
1) The test case issues a command code 00 (TEST UNIT READY) via the SG_IO
interface with: dxfer_len == 524288, dxdfer_dir == SG_DXFER_FROM_DEV
and a corresponding dxferp. The peculiar thing about this is that TUR
is not reading from the device.
2) In sg_start_req() the invocation of blk_rq_map_user() effectively
bounces the user-space buffer. As if the device was to transfer into
it. Since commit a45b599ad808 ("scsi: sg: allocate with __GFP_ZERO in
sg_build_indirect()") we make sure this first bounce buffer is
allocated with GFP_ZERO.
3) For the rest of the story we keep ignoring that we have a TUR, so the
device won't touch the buffer we prepare as if the we had a
DMA_FROM_DEVICE type of situation. My setup uses a virtio-scsi device
and the buffer allocated by SG is mapped by the function
virtqueue_add_split() which uses DMA_FROM_DEVICE for the "in" sgs (here
scatter-gather and not scsi generics). This mapping involves bouncing
via the swiotlb (we need swiotlb to do virtio in protected guest like
s390 Secure Execution, or AMD SEV).
4) When the SCSI TUR is done, we first copy back the content of the second
(that is swiotlb) bounce buffer (which most likely contains some
previous IO data), to the first bounce buffer, which contains all
zeros. Then we copy back the content of the first bounce buffer to
the user-space buffer.
5) The test case detects that the buffer, which it zero-initialized,
ain't all zeros and fails.
One can argue that this is an swiotlb problem, because without swiotlb
we leak all zeros, and the swiotlb should be transparent in a sense that
it does not affect the outcome (if all other participants are well
behaved).
Copying the content of the original buffer into the swiotlb buffer is
the only way I can think of to make swiotlb transparent in such
scenarios. So let's do just that if in doubt, but allow the driver
to tell us that the whole mapped buffer is going to be overwritten,
in which case we can preserve the old behavior and avoid the performance
impact of the extra bounce.
Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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reporting
commit 44a3918c8245ab10c6c9719dd12e7a8d291980d8 upstream.
With unprivileged eBPF enabled, eIBRS (without retpoline) is vulnerable
to Spectre v2 BHB-based attacks.
When both are enabled, print a warning message and report it in the
'spectre_v2' sysfs vulnerabilities file.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
[fllinden@amazon.com: backported to 5.15]
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 1d02b444b8d1345ea4708db3bab4db89a7784b55 upstream.
__setup() handlers should generally return 1 to indicate that the
boot options have been handled.
Using invalid option values causes the entire kernel boot option
string to be reported as Unknown and added to init's environment
strings, polluting it.
Unknown kernel command line parameters "BOOT_IMAGE=/boot/bzImage-517rc6
kprobe_event=p,syscall_any,$arg1 trace_options=quiet
trace_clock=jiffies", will be passed to user space.
Run /sbin/init as init process
with arguments:
/sbin/init
with environment:
HOME=/
TERM=linux
BOOT_IMAGE=/boot/bzImage-517rc6
kprobe_event=p,syscall_any,$arg1
trace_options=quiet
trace_clock=jiffies
Return 1 from the __setup() handlers so that init's environment is not
polluted with kernel boot options.
Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru
Link: https://lkml.kernel.org/r/20220303031744.32356-1-rdunlap@infradead.org
Cc: stable@vger.kernel.org
Fixes: 7bcfaf54f591 ("tracing: Add trace_options kernel command line parameter")
Fixes: e1e232ca6b8f ("tracing: Add trace_clock=<clock> kernel parameter")
Fixes: 970988e19eb0 ("tracing/kprobe: Add kprobe_event= boot parameter")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: Igor Zhbanov <i.zhbanov@omprussia.ru>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 1d1898f65616c4601208963c3376c1d828cbf2c7 upstream.
When trying to add a histogram against an event with the "cpu" field, it
was impossible due to "cpu" being a keyword to key off of the running CPU.
So to fix this, it was changed to "common_cpu" to match the other generic
fields (like "common_pid"). But since some scripts used "cpu" for keying
off of the CPU (for events that did not have "cpu" as a field, which is
most of them), a backward compatibility trick was added such that if "cpu"
was used as a key, and the event did not have "cpu" as a field name, then
it would fallback and switch over to "common_cpu".
This fix has a couple of subtle bugs. One was that when switching over to
"common_cpu", it did not change the field name, it just set a flag. But
the code still found a "cpu" field. The "cpu" field is used for filtering
and is returned when the event does not have a "cpu" field.
This was found by:
# cd /sys/kernel/tracing
# echo hist:key=cpu,pid:sort=cpu > events/sched/sched_wakeup/trigger
# cat events/sched/sched_wakeup/hist
Which showed the histogram unsorted:
{ cpu: 19, pid: 1175 } hitcount: 1
{ cpu: 6, pid: 239 } hitcount: 2
{ cpu: 23, pid: 1186 } hitcount: 14
{ cpu: 12, pid: 249 } hitcount: 2
{ cpu: 3, pid: 994 } hitcount: 5
Instead of hard coding the "cpu" checks, take advantage of the fact that
trace_event_field_field() returns a special field for "cpu" and "CPU" if
the event does not have "cpu" as a field. This special field has the
"filter_type" of "FILTER_CPU". Check that to test if the returned field is
of the CPU type instead of doing the string compare.
Also, fix the sorting bug by testing for the hist_field flag of
HIST_FIELD_FL_CPU when setting up the sort routine. Otherwise it will use
the special CPU field to know what compare routine to use, and since that
special field does not have a size, it returns tracing_map_cmp_none.
Cc: stable@vger.kernel.org
Fixes: 1e3bac71c505 ("tracing/histogram: Rename "cpu" to "common_cpu"")
Reported-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit b1e8206582f9d680cff7d04828708c8b6ab32957 upstream.
Where commit 4ef0c5c6b5ba ("kernel/sched: Fix sched_fork() access an
invalid sched_task_group") fixed a fork race vs cgroup, it opened up a
race vs syscalls by not placing the task on the runqueue before it
gets exposed through the pidhash.
Commit 13765de8148f ("sched/fair: Fix fault in reweight_entity") is
trying to fix a single instance of this, instead fix the whole class
of issues, effectively reverting this commit.
Fixes: 4ef0c5c6b5ba ("kernel/sched: Fix sched_fork() access an invalid sched_task_group")
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Tadeusz Struk <tadeusz.struk@linaro.org>
Tested-by: Zhang Qiao <zhangqiao22@huawei.com>
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Link: https://lkml.kernel.org/r/YgoeCbwj5mbCR0qA@hirez.programming.kicks-ass.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 30939293262eb433c960c4532a0d59c4073b2b84 upstream.
When tracing the whole disk, 'dropped' and 'msg' will be created
under 'q->debugfs_dir' and 'bt->dir' is NULL, thus blk_trace_free()
won't remove those files. What's worse, the following UAF can be
triggered because of accessing stale 'dropped' and 'msg':
==================================================================
BUG: KASAN: use-after-free in blk_dropped_read+0x89/0x100
Read of size 4 at addr ffff88816912f3d8 by task blktrace/1188
CPU: 27 PID: 1188 Comm: blktrace Not tainted 5.17.0-rc4-next-20220217+ #469
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-4
Call Trace:
<TASK>
dump_stack_lvl+0x34/0x44
print_address_description.constprop.0.cold+0xab/0x381
? blk_dropped_read+0x89/0x100
? blk_dropped_read+0x89/0x100
kasan_report.cold+0x83/0xdf
? blk_dropped_read+0x89/0x100
kasan_check_range+0x140/0x1b0
blk_dropped_read+0x89/0x100
? blk_create_buf_file_callback+0x20/0x20
? kmem_cache_free+0xa1/0x500
? do_sys_openat2+0x258/0x460
full_proxy_read+0x8f/0xc0
vfs_read+0xc6/0x260
ksys_read+0xb9/0x150
? vfs_write+0x3d0/0x3d0
? fpregs_assert_state_consistent+0x55/0x60
? exit_to_user_mode_prepare+0x39/0x1e0
do_syscall_64+0x35/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fbc080d92fd
Code: ce 20 00 00 75 10 b8 00 00 00 00 0f 05 48 3d 01 f0 ff ff 73 31 c3 48 83 1
RSP: 002b:00007fbb95ff9cb0 EFLAGS: 00000293 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007fbb95ff9dc0 RCX: 00007fbc080d92fd
RDX: 0000000000000100 RSI: 00007fbb95ff9cc0 RDI: 0000000000000045
RBP: 0000000000000045 R08: 0000000000406299 R09: 00000000fffffffd
R10: 000000000153afa0 R11: 0000000000000293 R12: 00007fbb780008c0
R13: 00007fbb78000938 R14: 0000000000608b30 R15: 00007fbb780029c8
</TASK>
Allocated by task 1050:
kasan_save_stack+0x1e/0x40
__kasan_kmalloc+0x81/0xa0
do_blk_trace_setup+0xcb/0x410
__blk_trace_setup+0xac/0x130
blk_trace_ioctl+0xe9/0x1c0
blkdev_ioctl+0xf1/0x390
__x64_sys_ioctl+0xa5/0xe0
do_syscall_64+0x35/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xae
Freed by task 1050:
kasan_save_stack+0x1e/0x40
kasan_set_track+0x21/0x30
kasan_set_free_info+0x20/0x30
__kasan_slab_free+0x103/0x180
kfree+0x9a/0x4c0
__blk_trace_remove+0x53/0x70
blk_trace_ioctl+0x199/0x1c0
blkdev_common_ioctl+0x5e9/0xb30
blkdev_ioctl+0x1a5/0x390
__x64_sys_ioctl+0xa5/0xe0
do_syscall_64+0x35/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xae
The buggy address belongs to the object at ffff88816912f380
which belongs to the cache kmalloc-96 of size 96
The buggy address is located 88 bytes inside of
96-byte region [ffff88816912f380, ffff88816912f3e0)
The buggy address belongs to the page:
page:000000009a1b4e7c refcount:1 mapcount:0 mapping:0000000000000000 index:0x0f
flags: 0x17ffffc0000200(slab|node=0|zone=2|lastcpupid=0x1fffff)
raw: 0017ffffc0000200 ffffea00044f1100 dead000000000002 ffff88810004c780
raw: 0000000000000000 0000000000200020 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff88816912f280: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
ffff88816912f300: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
>ffff88816912f380: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
^
ffff88816912f400: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
ffff88816912f480: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
==================================================================
Fixes: c0ea57608b69 ("blktrace: remove debugfs file dentries from struct blk_trace")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20220228034354.4047385-1-yukuai3@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 0ac983f512033cb7b5e210c9589768ad25b1e36b upstream.
Long story short recursively enforcing RLIMIT_NPROC when it is not
enforced on the process that creates a new user namespace, causes
currently working code to fail. There is no reason to enforce
RLIMIT_NPROC recursively when we don't enforce it normally so update
the code to detect this case.
I would like to simply use capable(CAP_SYS_RESOURCE) to detect when
RLIMIT_NPROC is not enforced upon the caller. Unfortunately because
RLIMIT_NPROC is charged and checked for enforcement based upon the
real uid, using capable() which is euid based is inconsistent with reality.
Come as close as possible to testing for capable(CAP_SYS_RESOURCE) by
testing for when the real uid would match the conditions when
CAP_SYS_RESOURCE would be present if the real uid was the effective
uid.
Reported-by: Etienne Dechamps <etienne@edechamps.fr>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=215596
Link: https://lkml.kernel.org/r/e9589141-cfeb-90cd-2d0e-83a62787239a@edechamps.fr
Link: https://lkml.kernel.org/r/87sfs8jmpz.fsf_-_@email.froward.int.ebiederm.org
Cc: stable@vger.kernel.org
Fixes: 21d1c5e386bc ("Reimplement RLIMIT_NPROC on top of ucounts")
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 0e3135d3bfa5dfb658145238d2bc723a8e30c3a3 ]
It seems inc_misses_counter() suffers from same issue fixed in
the commit d979617aa84d ("bpf: Fixes possible race in update_prog_stats()
for 32bit arches"):
As it can run while interrupts are enabled, it could
be re-entered and the u64_stats syncp could be mangled.
Fixes: 9ed9e9ba2337 ("bpf: Count the number of times recursion was prevented")
Signed-off-by: He Fengqing <hefengqing@huawei.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/r/20220122102936.1219518-1-hefengqing@huawei.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 61a0abaee2092eee69e44fe60336aa2f5b578938 ]
Commit 316580b69d0a ("u64_stats: provide u64_stats_t type")
fixed possible load/store tearing on 64bit arches.
For instance the following C code
stats->nsecs += sched_clock() - start;
Could be rightfully implemented like this by a compiler,
confusing concurrent readers a lot:
stats->nsecs += sched_clock();
// arbitrary delay
stats->nsecs -= start;
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211026214133.3114279-4-eric.dumazet@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 1c1857d400355e96f0fe8b32adc6fa7594d03b52 ]
kstrndup() is a memory allocation-related function, it returns NULL when
some internal memory errors happen. It is better to check the return
value of it so to catch the memory error in time.
Link: https://lkml.kernel.org/r/tencent_4D6E270731456EB88712ED7F13883C334906@qq.com
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: a42e3c4de964 ("tracing/probe: Add immediate string parameter support")
Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 8c7224245557707c613f130431cafbaaa4889615 ]
kstrdup() returns NULL when some internal memory errors happen, it is
better to check the return value of it so to catch the memory error in
time.
Link: https://lkml.kernel.org/r/tencent_3C2E330722056D7891D2C83F29C802734B06@qq.com
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: 33ea4b24277b ("perf/core: Implement the 'perf_uprobe' PMU")
Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 4f67cca70c0f615e9cfe6ac42244f3416ec60877 ]
synth_events is returning -EINVAL if the dyn_event create command does
not contain ' \t'. This prevents other systems from getting called back.
synth_events needs to return -ECANCELED in these cases when the command
is not targeting the synth_event system.
Link: https://lore.kernel.org/linux-trace-devel/20210930223821.11025-1-beaub@linux.microsoft.com
Fixes: c9e759b1e8456 ("tracing: Rework synthetic event command parsing")
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit e7f7c99ba911f56bc338845c1cd72954ba591707 ]
Recently while investigating a problem with rr and signals I noticed
that siglock is dropped in ptrace_signal and get_signal does not jump
to relock.
Looking farther to see if the problem is anywhere else I see that
do_signal_stop also returns if signal_group_exit is true. I believe
that test can now never be true, but it is a bit hard to trace
through and be certain.
Testing signal_group_exit is not expensive, so move the test for
signal_group_exit into the for loop inside of get_signal to ensure
the test is never skipped improperly.
This has been a potential problem since I added the test for
signal_group_exit was added.
Fixes: 35634ffa1751 ("signal: Always notice exiting tasks")
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/875yssekcd.fsf_-_@email.froward.int.ebiederm.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit f37c3bbc635994eda203a6da4ba0f9d05165a8d6 ]
Since referencing user space pointers is special, if the user wants to
filter on a field that is a pointer to user space, then they need to
specify it.
Add a ".ustring" attribute to the field name for filters to state that the
field is pointing to user space such that the kernel can take the
appropriate action to read that pointer.
Link: https://lore.kernel.org/all/yt9d8rvmt2jq.fsf@linux.ibm.com/
Fixes: 77360f9bbc7e ("tracing: Add test for user space strings when filtering on string pointers")
Tested-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 13765de8148f71fa795e0a6607de37c49ea5915a ]
Syzbot found a GPF in reweight_entity. This has been bisected to
commit 4ef0c5c6b5ba ("kernel/sched: Fix sched_fork() access an invalid
sched_task_group")
There is a race between sched_post_fork() and setpriority(PRIO_PGRP)
within a thread group that causes a null-ptr-deref in
reweight_entity() in CFS. The scenario is that the main process spawns
number of new threads, which then call setpriority(PRIO_PGRP, 0, -20),
wait, and exit. For each of the new threads the copy_process() gets
invoked, which adds the new task_struct and calls sched_post_fork()
for it.
In the above scenario there is a possibility that
setpriority(PRIO_PGRP) and set_one_prio() will be called for a thread
in the group that is just being created by copy_process(), and for
which the sched_post_fork() has not been executed yet. This will
trigger a null pointer dereference in reweight_entity(), as it will
try to access the run queue pointer, which hasn't been set.
Before the mentioned change the cfs_rq pointer for the task has been
set in sched_fork(), which is called much earlier in copy_process(),
before the new task is added to the thread_group. Now it is done in
the sched_post_fork(), which is called after that. To fix the issue
the remove the update_load param from the update_load param() function
and call reweight_task() only if the task flag doesn't have the
TASK_NEW flag set.
Fixes: 4ef0c5c6b5ba ("kernel/sched: Fix sched_fork() access an invalid sched_task_group")
Reported-by: syzbot+af7a719bc92395ee41b3@syzkaller.appspotmail.com
Signed-off-by: Tadeusz Struk <tadeusz.struk@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20220203161846.1160750-1-tadeusz.struk@linaro.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 77360f9bbc7e5e2ab7a2c8b4c0244fbbfcfc6f62 ]
Pingfan reported that the following causes a fault:
echo "filename ~ \"cpu\"" > events/syscalls/sys_enter_openat/filter
echo 1 > events/syscalls/sys_enter_at/enable
The reason is that trace event filter treats the user space pointer
defined by "filename" as a normal pointer to compare against the "cpu"
string. The following bug happened:
kvm-03-guest16 login: [72198.026181] BUG: unable to handle page fault for address: 00007fffaae8ef60
#PF: supervisor read access in kernel mode
#PF: error_code(0x0001) - permissions violation
PGD 80000001008b7067 P4D 80000001008b7067 PUD 2393f1067 PMD 2393ec067 PTE 8000000108f47867
Oops: 0001 [#1] PREEMPT SMP PTI
CPU: 1 PID: 1 Comm: systemd Kdump: loaded Not tainted 5.14.0-32.el9.x86_64 #1
Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
RIP: 0010:strlen+0x0/0x20
Code: 48 89 f9 74 09 48 83 c1 01 80 39 00 75 f7 31 d2 44 0f b6 04 16 44 88 04 11
48 83 c2 01 45 84 c0 75 ee c3 0f 1f 80 00 00 00 00 <80> 3f 00 74 10 48 89 f8
48 83 c0 01 80 38 00 75 f7 48 29 f8 c3 31
RSP: 0018:ffffb5b900013e48 EFLAGS: 00010246
RAX: 0000000000000018 RBX: ffff8fc1c49ede00 RCX: 0000000000000000
RDX: 0000000000000020 RSI: ffff8fc1c02d601c RDI: 00007fffaae8ef60
RBP: 00007fffaae8ef60 R08: 0005034f4ddb8ea4 R09: 0000000000000000
R10: ffff8fc1c02d601c R11: 0000000000000000 R12: ffff8fc1c8a6e380
R13: 0000000000000000 R14: ffff8fc1c02d6010 R15: ffff8fc1c00453c0
FS: 00007fa86123db40(0000) GS:ffff8fc2ffd00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fffaae8ef60 CR3: 0000000102880001 CR4: 00000000007706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
filter_pred_pchar+0x18/0x40
filter_match_preds+0x31/0x70
ftrace_syscall_enter+0x27a/0x2c0
syscall_trace_enter.constprop.0+0x1aa/0x1d0
do_syscall_64+0x16/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fa861d88664
The above happened because the kernel tried to access user space directly
and triggered a "supervisor read access in kernel mode" fault. Worse yet,
the memory could not even be loaded yet, and a SEGFAULT could happen as
well. This could be true for kernel space accessing as well.
To be even more robust, test both kernel and user space strings. If the
string fails to read, then simply have the filter fail.
Note, TASK_SIZE is used to determine if the pointer is user or kernel space
and the appropriate strncpy_from_kernel/user_nofault() function is used to
copy the memory. For some architectures, the compare to TASK_SIZE may always
pick user space or kernel space. If it gets it wrong, the only thing is that
the filter will fail to match. In the future, this needs to be fixed to have
the event denote which should be used. But failing a filter is much better
than panicing the machine, and that can be solved later.
Link: https://lore.kernel.org/all/20220107044951.22080-1-kernelfans@gmail.com/
Link: https://lkml.kernel.org/r/20220110115532.536088fd@gandalf.local.home
Cc: stable@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Reported-by: Pingfan Liu <kernelfans@gmail.com>
Tested-by: Pingfan Liu <kernelfans@gmail.com>
Fixes: 87a342f5db69d ("tracing/filters: Support filtering for char * strings")
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 302e9edd54985f584cfc180098f3554774126969 upstream.
If a trigger is set on an event to disable or enable tracing within an
instance, then tracing should be disabled or enabled in the instance and
not at the top level, which is confusing to users.
Link: https://lkml.kernel.org/r/20220223223837.14f94ec3@rorschach.local.home
Cc: stable@vger.kernel.org
Fixes: ae63b31e4d0e2 ("tracing: Separate out trace events from global variables")
Tested-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit ce33c845b030c9cf768370c951bc699470b09fa7 upstream.
The stacktrace event trigger is not dumping the stacktrace to the instance
where it was enabled, but to the global "instance."
Use the private_data, pointing to the trigger file, to figure out the
corresponding trace instance, and use it in the trigger action, like
snapshot_trigger does.
Link: https://lkml.kernel.org/r/afbb0b4f18ba92c276865bc97204d438473f4ebc.1645396236.git.bristot@kernel.org
Cc: stable@vger.kernel.org
Fixes: ae63b31e4d0e2 ("tracing: Separate out trace events from global variables")
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Tested-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 75134f16e7dd0007aa474b281935c5f42e79f2c8 upstream.
syzbot reported various soft lockups caused by bpf batch operations.
INFO: task kworker/1:1:27 blocked for more than 140 seconds.
INFO: task hung in rcu_barrier
Nothing prevents batch ops to process huge amount of data,
we need to add schedule points in them.
Note that maybe_wait_bpf_programs(map) calls from
generic_map_delete_batch() can be factorized by moving
the call after the loop.
This will be done later in -next tree once we get this fix merged,
unless there is strong opinion doing this optimization sooner.
Fixes: aa2e93b8e58e ("bpf: Add generic support for update and delete batch ops")
Fixes: cb4d03ab499d ("bpf: Add generic support for lookup batch op")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Brian Vazquez <brianvv@google.com>
Link: https://lore.kernel.org/bpf/20220217181902.808742-1-eric.dumazet@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 467a726b754f474936980da793b4ff2ec3e382a7 upstream.
The idea is to check: a) the owning user_ns of cgroup_ns, b)
capabilities in init_user_ns.
The commit 24f600856418 ("cgroup-v1: Require capabilities to set
release_agent") got this wrong in the write handler of release_agent
since it checked user_ns of the opener (may be different from the owning
user_ns of cgroup_ns).
Secondly, to avoid possibly confused deputy, the capability of the
opener must be checked.
Fixes: 24f600856418 ("cgroup-v1: Require capabilities to set release_agent")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/stable/20220216121142.GB30035@blackbody.suse.cz/
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Reviewed-by: Masami Ichikawa(CIP) <masami.ichikawa@cybertrust.co.jp>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 05c7b7a92cc87ff8d7fde189d0fade250697573c upstream.
As previously discussed(https://lkml.org/lkml/2022/1/20/51),
cpuset_attach() is affected with similar cpu hotplug race,
as follow scenario:
cpuset_attach() cpu hotplug
--------------------------- ----------------------
down_write(cpuset_rwsem)
guarantee_online_cpus() // (load cpus_attach)
sched_cpu_deactivate
set_cpu_active()
// will change cpu_active_mask
set_cpus_allowed_ptr(cpus_attach)
__set_cpus_allowed_ptr_locked()
// (if the intersection of cpus_attach and
cpu_active_mask is empty, will return -EINVAL)
up_write(cpuset_rwsem)
To avoid races such as described above, protect cpuset_attach() call
with cpu_hotplug_lock.
Fixes: be367d099270 ("cgroups: let ss->can_attach and ss->attach do whole threadgroups at a time")
Cc: stable@vger.kernel.org # v2.6.32+
Reported-by: Zhao Gongyi <zhaogongyi@huawei.com>
Signed-off-by: Zhang Qiao <zhangqiao22@huawei.com>
Acked-by: Waiman Long <longman@redhat.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 28df029d53a2fd80c1b8674d47895648ad26dcfb upstream.
A kernel exception was hit when trying to dump /proc/lockdep_chains after
lockdep report "BUG: MAX_LOCKDEP_CHAIN_HLOCKS too low!":
Unable to handle kernel paging request at virtual address 00054005450e05c3
...
00054005450e05c3] address between user and kernel address ranges
...
pc : [0xffffffece769b3a8] string+0x50/0x10c
lr : [0xffffffece769ac88] vsnprintf+0x468/0x69c
...
Call trace:
string+0x50/0x10c
vsnprintf+0x468/0x69c
seq_printf+0x8c/0xd8
print_name+0x64/0xf4
lc_show+0xb8/0x128
seq_read_iter+0x3cc/0x5fc
proc_reg_read_iter+0xdc/0x1d4
The cause of the problem is the function lock_chain_get_class() will
shift lock_classes index by 1, but the index don't need to be shifted
anymore since commit 01bb6f0af992 ("locking/lockdep: Change the range
of class_idx in held_lock struct") already change the index to start
from 0.
The lock_classes[-1] located at chain_hlocks array. When printing
lock_classes[-1] after the chain_hlocks entries are modified, the
exception happened.
The output of lockdep_chains are incorrect due to this problem too.
Fixes: f611e8cf98ec ("lockdep: Take read/write status in consideration when generate chainkey")
Signed-off-by: Cheng Jui Wang <cheng-jui.wang@mediatek.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/20220210105011.21712-1-cheng-jui.wang@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
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commit ddc204b517e60ae64db34f9832dc41dafa77c751 upstream.
I was made aware of the following lockdep splat:
[ 2516.308763] =====================================================
[ 2516.309085] WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected
[ 2516.309433] 5.14.0-51.el9.aarch64+debug #1 Not tainted
[ 2516.309703] -----------------------------------------------------
[ 2516.310149] stress-ng/153663 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
[ 2516.310512] ffff0000e422b198 (&newf->file_lock){+.+.}-{2:2}, at: fd_install+0x368/0x4f0
[ 2516.310944]
and this task is already holding:
[ 2516.311248] ffff0000c08140d8 (&sighand->siglock){-.-.}-{2:2}, at: copy_process+0x1e2c/0x3e80
[ 2516.311804] which would create a new lock dependency:
[ 2516.312066] (&sighand->siglock){-.-.}-{2:2} -> (&newf->file_lock){+.+.}-{2:2}
[ 2516.312446]
but this new dependency connects a HARDIRQ-irq-safe lock:
[ 2516.312983] (&sighand->siglock){-.-.}-{2:2}
:
[ 2516.330700] Possible interrupt unsafe locking scenario:
[ 2516.331075] CPU0 CPU1
[ 2516.331328] ---- ----
[ 2516.331580] lock(&newf->file_lock);
[ 2516.331790] local_irq_disable();
[ 2516.332231] lock(&sighand->siglock);
[ 2516.332579] lock(&newf->file_lock);
[ 2516.332922] <Interrupt>
[ 2516.333069] lock(&sighand->siglock);
[ 2516.333291]
*** DEADLOCK ***
[ 2516.389845]
stack backtrace:
[ 2516.390101] CPU: 3 PID: 153663 Comm: stress-ng Kdump: loaded Not tainted 5.14.0-51.el9.aarch64+debug #1
[ 2516.390756] Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
[ 2516.391155] Call trace:
[ 2516.391302] dump_backtrace+0x0/0x3e0
[ 2516.391518] show_stack+0x24/0x30
[ 2516.391717] dump_stack_lvl+0x9c/0xd8
[ 2516.391938] dump_stack+0x1c/0x38
[ 2516.392247] print_bad_irq_dependency+0x620/0x710
[ 2516.392525] check_irq_usage+0x4fc/0x86c
[ 2516.392756] check_prev_add+0x180/0x1d90
[ 2516.392988] validate_chain+0x8e0/0xee0
[ 2516.393215] __lock_acquire+0x97c/0x1e40
[ 2516.393449] lock_acquire.part.0+0x240/0x570
[ 2516.393814] lock_acquire+0x90/0xb4
[ 2516.394021] _raw_spin_lock+0xe8/0x154
[ 2516.394244] fd_install+0x368/0x4f0
[ 2516.394451] copy_process+0x1f5c/0x3e80
[ 2516.394678] kernel_clone+0x134/0x660
[ 2516.394895] __do_sys_clone3+0x130/0x1f4
[ 2516.395128] __arm64_sys_clone3+0x5c/0x7c
[ 2516.395478] invoke_syscall.constprop.0+0x78/0x1f0
[ 2516.395762] el0_svc_common.constprop.0+0x22c/0x2c4
[ 2516.396050] do_el0_svc+0xb0/0x10c
[ 2516.396252] el0_svc+0x24/0x34
[ 2516.396436] el0t_64_sync_handler+0xa4/0x12c
[ 2516.396688] el0t_64_sync+0x198/0x19c
[ 2517.491197] NET: Registered PF_ATMPVC protocol family
[ 2517.491524] NET: Registered PF_ATMSVC protocol family
[ 2591.991877] sched: RT throttling activated
One way to solve this problem is to move the fd_install() call out of
the sighand->siglock critical section.
Before commit 6fd2fe494b17 ("copy_process(): don't use ksys_close()
on cleanups"), the pidfd installation was done without holding both
the task_list lock and the sighand->siglock. Obviously, holding these
two locks are not really needed to protect the fd_install() call.
So move the fd_install() call down to after the releases of both locks.
Link: https://lore.kernel.org/r/20220208163912.1084752-1-longman@redhat.com
Fixes: 6fd2fe494b17 ("copy_process(): don't use ksys_close() on cleanups")
Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit c923a8e7edb010da67424077cbf1a6f1396ebd2e upstream.
During set*id() which cred->ucounts to charge the the current process
to is not known until after set_cred_ucounts. So move the
RLIMIT_NPROC checking into a new helper flag_nproc_exceeded and call
flag_nproc_exceeded after set_cred_ucounts.
This is very much an arbitrary subset of the places where we currently
change the RLIMIT_NPROC accounting, designed to preserve the existing
logic.
Fixing the existing logic will be the subject of another series of
changes.
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20220216155832.680775-4-ebiederm@xmission.com
Fixes: 21d1c5e386bc ("Reimplement RLIMIT_NPROC on top of ucounts")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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set_user
commit c16bdeb5a39ffa3f32b32f812831a2092d2a3061 upstream.
Solar Designer <solar@openwall.com> wrote:
> I'm not aware of anyone actually running into this issue and reporting
> it. The systems that I personally know use suexec along with rlimits
> still run older/distro kernels, so would not yet be affected.
>
> So my mention was based on my understanding of how suexec works, and
> code review. Specifically, Apache httpd has the setting RLimitNPROC,
> which makes it set RLIMIT_NPROC:
>
> https://httpd.apache.org/docs/2.4/mod/core.html#rlimitnproc
>
> The above documentation for it includes:
>
> "This applies to processes forked from Apache httpd children servicing
> requests, not the Apache httpd children themselves. This includes CGI
> scripts and SSI exec commands, but not any processes forked from the
> Apache httpd parent, such as piped logs."
>
> In code, there are:
>
> ./modules/generators/mod_cgid.c: ( (cgid_req.limits.limit_nproc_set) && ((rc = apr_procattr_limit_set(procattr, APR_LIMIT_NPROC,
> ./modules/generators/mod_cgi.c: ((rc = apr_procattr_limit_set(procattr, APR_LIMIT_NPROC,
> ./modules/filters/mod_ext_filter.c: rv = apr_procattr_limit_set(procattr, APR_LIMIT_NPROC, conf->limit_nproc);
>
> For example, in mod_cgi.c this is in run_cgi_child().
>
> I think this means an httpd child sets RLIMIT_NPROC shortly before it
> execs suexec, which is a SUID root program. suexec then switches to the
> target user and execs the CGI script.
>
> Before 2863643fb8b9, the setuid() in suexec would set the flag, and the
> target user's process count would be checked against RLIMIT_NPROC on
> execve(). After 2863643fb8b9, the setuid() in suexec wouldn't set the
> flag because setuid() is (naturally) called when the process is still
> running as root (thus, has those limits bypass capabilities), and
> accordingly execve() would not check the target user's process count
> against RLIMIT_NPROC.
In commit 2863643fb8b9 ("set_user: add capability check when
rlimit(RLIMIT_NPROC) exceeds") capable calls were added to set_user to
make it more consistent with fork. Unfortunately because of call site
differences those capable calls were checking the credentials of the
user before set*id() instead of after set*id().
This breaks enforcement of RLIMIT_NPROC for applications that set the
rlimit and then call set*id() while holding a full set of
capabilities. The capabilities are only changed in the new credential
in security_task_fix_setuid().
The code in apache suexec appears to follow this pattern.
Commit 909cc4ae86f3 ("[PATCH] Fix two bugs with process limits
(RLIMIT_NPROC)") where this check was added describes the targes of this
capability check as:
2/ When a root-owned process (e.g. cgiwrap) sets up process limits and then
calls setuid, the setuid should fail if the user would then be running
more than rlim_cur[RLIMIT_NPROC] processes, but it doesn't. This patch
adds an appropriate test. With this patch, and per-user process limit
imposed in cgiwrap really works.
So the original use case of this check also appears to match the broken
pattern.
Restore the enforcement of RLIMIT_NPROC by removing the bad capable
checks added in set_user. This unfortunately restores the
inconsistent state the code has been in for the last 11 years, but
dealing with the inconsistencies looks like a larger problem.
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/20210907213042.GA22626@openwall.com/
Link: https://lkml.kernel.org/r/20220212221412.GA29214@openwall.com
Link: https://lkml.kernel.org/r/20220216155832.680775-1-ebiederm@xmission.com
Fixes: 2863643fb8b9 ("set_user: add capability check when rlimit(RLIMIT_NPROC) exceeds")
History-Tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git
Reviewed-by: Solar Designer <solar@openwall.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 8f2f9c4d82f24f172ae439e5035fc1e0e4c229dd upstream.
Michal Koutný <mkoutny@suse.com> wrote:
> It was reported that v5.14 behaves differently when enforcing
> RLIMIT_NPROC limit, namely, it allows one more task than previously.
> This is consequence of the commit 21d1c5e386bc ("Reimplement
> RLIMIT_NPROC on top of ucounts") that missed the sharpness of
> equality in the forking path.
This can be fixed either by fixing the test or by moving the increment
to be before the test. Fix it my moving copy_creds which contains
the increment before is_ucounts_overlimit.
In the case of CLONE_NEWUSER the ucounts in the task_cred changes.
The function is_ucounts_overlimit needs to use the final version of
the ucounts for the new process. Which means moving the
is_ucounts_overlimit test after copy_creds is necessary.
Both the test in fork and the test in set_user were semantically
changed when the code moved to ucounts. The change of the test in
fork was bad because it was before the increment. The test in
set_user was wrong and the change to ucounts fixed it. So this
fix only restores the old behavior in one lcation not two.
Link: https://lkml.kernel.org/r/20220204181144.24462-1-mkoutny@suse.com
Link: https://lkml.kernel.org/r/20220216155832.680775-2-ebiederm@xmission.com
Cc: stable@vger.kernel.org
Reported-by: Michal Koutný <mkoutny@suse.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Fixes: 21d1c5e386bc ("Reimplement RLIMIT_NPROC on top of ucounts")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
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commit a55d07294f1e9b576093bdfa95422f8119941e83 upstream.
Michal Koutný <mkoutny@suse.com> wrote:
> Tasks are associated to multiple users at once. Historically and as per
> setrlimit(2) RLIMIT_NPROC is enforce based on real user ID.
>
> The commit 21d1c5e386bc ("Reimplement RLIMIT_NPROC on top of ucounts")
> made the accounting structure "indexed" by euid and hence potentially
> account tasks differently.
>
> The effective user ID may be different e.g. for setuid programs but
> those are exec'd into already existing task (i.e. below limit), so
> different accounting is moot.
>
> Some special setresuid(2) users may notice the difference, justifying
> this fix.
I looked at cred->ucount and it is only used for rlimit operations
that were previously stored in cred->user. Making the fact
cred->ucount can refer to a different user from cred->user a bug,
affecting all uses of cred->ulimit not just RLIMIT_NPROC.
Fix set_cred_ucounts to always use the real uid not the effective uid.
Further simplify set_cred_ucounts by noticing that set_cred_ucounts
somehow retained a draft version of the check to see if alloc_ucounts
was needed that checks the new->user and new->user_ns against the
current_real_cred(). Remove that draft version of the check.
All that matters for setting the cred->ucounts are the user_ns and uid
fields in the cred.
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20220207121800.5079-4-mkoutny@suse.com
Link: https://lkml.kernel.org/r/20220216155832.680775-3-ebiederm@xmission.com
Reported-by: Michal Koutný <mkoutny@suse.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Fixes: 21d1c5e386bc ("Reimplement RLIMIT_NPROC on top of ucounts")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 99c31f9feda41d0f10d030dc04ba106c93295aa2 upstream.
Any cred that is destined for use by commit_creds must have a non-NULL
cred->ucounts field. Only curing credential construction is a NULL
cred->ucounts valid. Only abort_creds, put_cred, and put_cred_rcu
needs to deal with a cred with a NULL ucount. As set_cred_ucounts is
non of those case don't confuse people by handling something that can
not happen.
Link: https://lkml.kernel.org/r/871r4irzds.fsf_-_@disp2133
Tested-by: Yu Zhao <yuzhao@google.com>
Reviewed-by: Alexey Gladkov <legion@kernel.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
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commit 0cbae9e24fa7d6c6e9f828562f084da82217a0c5 upstream.
While examining is_ucounts_overlimit and reading the various messages
I realized that is_ucounts_overlimit fails to deal with counts that
may have wrapped.
Being wrapped should be a transitory state for counts and they should
never be wrapped for long, but it can happen so handle it.
Cc: stable@vger.kernel.org
Fixes: 21d1c5e386bc ("Reimplement RLIMIT_NPROC on top of ucounts")
Link: https://lkml.kernel.org/r/20220216155832.680775-5-ebiederm@xmission.com
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 3203ce39ac0b2a57a84382ec184c7d4a0bede175 ]
The kernel parameter "tp_printk_stop_on_boot" starts with "tp_printk" which is
the same as another kernel parameter "tp_printk". If "tp_printk" setup is
called before the "tp_printk_stop_on_boot", it will override the latter
and keep it from being set.
This is similar to other kernel parameter issues, such as:
Commit 745a600cf1a6 ("um: console: Ignore console= option")
or init/do_mounts.c:45 (setup function of "ro" kernel param)
Fix it by checking for a "_" right after the "tp_printk" and if that
exists do not process the parameter.
Link: https://lkml.kernel.org/r/20220208195421.969326-1-jsyoo5b@gmail.com
Signed-off-by: JaeSang Yoo <jsyoo5b@gmail.com>
[ Fixed up change log and added space after if condition ]
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit dcb85f85fa6f142aae1fe86f399d4503d49f2b60 ]
While the stackleak plugin was already using notrace, objtool is now a
bit more picky. Update the notrace uses to noinstr. Silences the
following objtool warnings when building with:
CONFIG_DEBUG_ENTRY=y
CONFIG_STACK_VALIDATION=y
CONFIG_VMLINUX_VALIDATION=y
CONFIG_GCC_PLUGIN_STACKLEAK=y
vmlinux.o: warning: objtool: do_syscall_64()+0x9: call to stackleak_track_stack() leaves .noinstr.text section
vmlinux.o: warning: objtool: do_int80_syscall_32()+0x9: call to stackleak_track_stack() leaves .noinstr.text section
vmlinux.o: warning: objtool: exc_general_protection()+0x22: call to stackleak_track_stack() leaves .noinstr.text section
vmlinux.o: warning: objtool: fixup_bad_iret()+0x20: call to stackleak_track_stack() leaves .noinstr.text section
vmlinux.o: warning: objtool: do_machine_check()+0x27: call to stackleak_track_stack() leaves .noinstr.text section
vmlinux.o: warning: objtool: .text+0x5346e: call to stackleak_erase() leaves .noinstr.text section
vmlinux.o: warning: objtool: .entry.text+0x143: call to stackleak_erase() leaves .noinstr.text section
vmlinux.o: warning: objtool: .entry.text+0x10eb: call to stackleak_erase() leaves .noinstr.text section
vmlinux.o: warning: objtool: .entry.text+0x17f9: call to stackleak_erase() leaves .noinstr.text section
Note that the plugin's addition of calls to stackleak_track_stack() from
noinstr functions is expected to be safe, as it isn't runtime
instrumentation and is self-contained.
Cc: Alexander Popov <alex.popov@linux.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
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used"
[ Upstream commit 67d6212afda218d564890d1674bab28e8612170f ]
This reverts commit 774a1221e862b343388347bac9b318767336b20b.
We need to finish all async code before the module init sequence is
done. In the reverted commit the PF_USED_ASYNC flag was added to mark a
thread that called async_schedule(). Then the PF_USED_ASYNC flag was
used to determine whether or not async_synchronize_full() needs to be
invoked. This works when modprobe thread is calling async_schedule(),
but it does not work if module dispatches init code to a worker thread
which then calls async_schedule().
For example, PCI driver probing is invoked from a worker thread based on
a node where device is attached:
if (cpu < nr_cpu_ids)
error = work_on_cpu(cpu, local_pci_probe, &ddi);
else
error = local_pci_probe(&ddi);
We end up in a situation where a worker thread gets the PF_USED_ASYNC
flag set instead of the modprobe thread. As a result,
async_synchronize_full() is not invoked and modprobe completes without
waiting for the async code to finish.
The issue was discovered while loading the pm80xx driver:
(scsi_mod.scan=async)
modprobe pm80xx worker
...
do_init_module()
...
pci_call_probe()
work_on_cpu(local_pci_probe)
local_pci_probe()
pm8001_pci_probe()
scsi_scan_host()
async_schedule()
worker->flags |= PF_USED_ASYNC;
...
< return from worker >
...
if (current->flags & PF_USED_ASYNC) <--- false
async_synchronize_full();
Commit 21c3c5d28007 ("block: don't request module during elevator init")
fixed the deadlock issue which the reverted commit 774a1221e862
("module, async: async_synchronize_full() on module init iff async is
used") tried to fix.
Since commit 0fdff3ec6d87 ("async, kmod: warn on synchronous
request_module() from async workers") synchronous module loading from
async is not allowed.
Given that the original deadlock issue is fixed and it is no longer
allowed to call synchronous request_module() from async we can remove
PF_USED_ASYNC flag to make module init consistently invoke
async_synchronize_full() unless async module probe is requested.
Signed-off-by: Igor Pylypiv <ipylypiv@google.com>
Reviewed-by: Changyuan Lyu <changyuanl@google.com>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
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commit 5f4e5ce638e6a490b976ade4a40017b40abb2da0 upstream.
There's list corruption on cgrp_cpuctx_list. This happens on the
following path:
perf_cgroup_switch: list_for_each_entry(cgrp_cpuctx_list)
cpu_ctx_sched_in
ctx_sched_in
ctx_pinned_sched_in
merge_sched_in
perf_cgroup_event_disable: remove the event from the list
Use list_for_each_entry_safe() to allow removing an entry during
iteration.
Fixes: 058fe1c0440e ("perf/core: Make cgroup switch visit only cpuctxs with cgroup events")
Signed-off-by: Song Liu <song@kernel.org>
Reviewed-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220204004057.2961252-1-song@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 5c72263ef2fbe99596848f03758ae2dc593adf2c upstream.
Fatal SIGSYS signals (i.e. seccomp RET_KILL_* syscall filter actions)
were not being delivered to ptraced pid namespace init processes. Make
sure the SIGNAL_UNKILLABLE doesn't get set for these cases.
Reported-by: Robert Święcki <robert@swiecki.net>
Suggested-by: "Eric W. Biederman" <ebiederm@xmission.com>
Fixes: 00b06da29cf9 ("signal: Add SA_IMMUTABLE to ensure forced siganls do not get changed")
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com>
Link: https://lore.kernel.org/lkml/878rui8u4a.fsf@email.froward.int.ebiederm.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 495ac3069a6235bfdf516812a2a9b256671bbdf9 upstream.
If seccomp tries to kill a process, it should never see that process
again. To enforce this proactively, switch the mode to something
impossible. If encountered: WARN, reject all syscalls, and attempt to
kill the process again even harder.
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Will Drewry <wad@chromium.org>
Fixes: 8112c4f140fa ("seccomp: remove 2-phase API")
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit cb1f65c1e1424a4b5e4a86da8aa3b8fd8459c8ec upstream.
After commit e3728b50cd9b ("ACPI: PM: s2idle: Avoid possible race
related to the EC GPE") wakeup interrupts occurring immediately after
the one discarded by acpi_s2idle_wake() may be missed. Moreover, if
the SCI triggers again immediately after the rearming in
acpi_s2idle_wake(), that wakeup may be missed too.
The problem is that pm_system_irq_wakeup() only calls pm_system_wakeup()
when pm_wakeup_irq is 0, but that's not the case any more after the
interrupt causing acpi_s2idle_wake() to run until pm_wakeup_irq is
cleared by the pm_wakeup_clear() call in s2idle_loop(). However,
there may be wakeup interrupts occurring in that time frame and if
that happens, they will be missed.
To address that issue first move the clearing of pm_wakeup_irq to
the point at which it is known that the interrupt causing
acpi_s2idle_wake() to tun will be discarded, before rearming the SCI
for wakeup. Moreover, because that only reduces the size of the
time window in which the issue may manifest itself, allow
pm_system_irq_wakeup() to register two second wakeup interrupts in
a row and, when discarding the first one, replace it with the second
one. [Of course, this assumes that only one wakeup interrupt can be
discarded in one go, but currently that is the case and I am not
aware of any plans to change that.]
Fixes: e3728b50cd9b ("ACPI: PM: s2idle: Avoid possible race related to the EC GPE")
Cc: 5.4+ <stable@vger.kernel.org> # 5.4+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 961c39121759ad09a89598ec4ccdd34ae0468a19 ]
When using per-process mode and event inheritance is set to true,
forked processes will create a new perf events via inherit_event() ->
perf_event_alloc(). But these events will not have ring buffers
assigned to them. Any call to wakeup will be dropped if it's called on
an event with no ring buffer assigned because that's the object that
holds the wakeup list.
If the child event is disabled due to a call to
perf_aux_output_begin() or perf_aux_output_end(), the wakeup is
dropped leaving userspace hanging forever on the poll.
Normally the event is explicitly re-enabled by userspace after it
wakes up to read the aux data, but in this case it does not get woken
up so the event remains disabled.
This can be reproduced when using Arm SPE and 'stress' which forks once
before running the workload. By looking at the list of aux buffers read,
it's apparent that they stop after the fork:
perf record -e arm_spe// -vvv -- stress -c 1
With this patch applied they continue to be printed. This behaviour
doesn't happen when using systemwide or per-cpu mode.
Reported-by: Ruben Ayrapetyan <Ruben.Ayrapetyan@arm.com>
Signed-off-by: James Clark <james.clark@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20211206113840.130802-2-james.clark@arm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
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