<feed xmlns='http://www.w3.org/2005/Atom'>
<title>user/sven/linux.git/include/linux, branch v4.14.181</title>
<subtitle>Linux Kernel
</subtitle>
<id>https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v4.14.181</id>
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<updated>2020-05-20T06:17:15Z</updated>
<entry>
<title>x86: Fix early boot crash on gcc-10, third try</title>
<updated>2020-05-20T06:17:15Z</updated>
<author>
<name>Borislav Petkov</name>
<email>bp@suse.de</email>
</author>
<published>2020-04-22T16:11:30Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=60753dc8290192714003b0a38269e2f7342810c9'/>
<id>urn:sha1:60753dc8290192714003b0a38269e2f7342810c9</id>
<content type='text'>
commit a9a3ed1eff3601b63aea4fb462d8b3b92c7c1e7e upstream.

... or the odyssey of trying to disable the stack protector for the
function which generates the stack canary value.

The whole story started with Sergei reporting a boot crash with a kernel
built with gcc-10:

  Kernel panic — not syncing: stack-protector: Kernel stack is corrupted in: start_secondary
  CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.6.0-rc5—00235—gfffb08b37df9 #139
  Hardware name: Gigabyte Technology Co., Ltd. To be filled by O.E.M./H77M—D3H, BIOS F12 11/14/2013
  Call Trace:
    dump_stack
    panic
    ? start_secondary
    __stack_chk_fail
    start_secondary
    secondary_startup_64
  -—-[ end Kernel panic — not syncing: stack—protector: Kernel stack is corrupted in: start_secondary

This happens because gcc-10 tail-call optimizes the last function call
in start_secondary() - cpu_startup_entry() - and thus emits a stack
canary check which fails because the canary value changes after the
boot_init_stack_canary() call.

To fix that, the initial attempt was to mark the one function which
generates the stack canary with:

  __attribute__((optimize("-fno-stack-protector"))) ... start_secondary(void *unused)

however, using the optimize attribute doesn't work cumulatively
as the attribute does not add to but rather replaces previously
supplied optimization options - roughly all -fxxx options.

The key one among them being -fno-omit-frame-pointer and thus leading to
not present frame pointer - frame pointer which the kernel needs.

The next attempt to prevent compilers from tail-call optimizing
the last function call cpu_startup_entry(), shy of carving out
start_secondary() into a separate compilation unit and building it with
-fno-stack-protector, was to add an empty asm("").

This current solution was short and sweet, and reportedly, is supported
by both compilers but we didn't get very far this time: future (LTO?)
optimization passes could potentially eliminate this, which leads us
to the third attempt: having an actual memory barrier there which the
compiler cannot ignore or move around etc.

That should hold for a long time, but hey we said that about the other
two solutions too so...

Reported-by: Sergei Trofimovich &lt;slyfox@gentoo.org&gt;
Signed-off-by: Borislav Petkov &lt;bp@suse.de&gt;
Tested-by: Kalle Valo &lt;kvalo@codeaurora.org&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Link: https://lkml.kernel.org/r/20200314164451.346497-1-slyfox@gentoo.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>gcc-10 warnings: fix low-hanging fruit</title>
<updated>2020-05-20T06:17:09Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2020-05-04T16:16:37Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=fb477f9c8930a58140b930ecc41c27470bcfc68c'/>
<id>urn:sha1:fb477f9c8930a58140b930ecc41c27470bcfc68c</id>
<content type='text'>
commit 9d82973e032e246ff5663c9805fbb5407ae932e3 upstream.

Due to a bug-report that was compiler-dependent, I updated one of my
machines to gcc-10.  That shows a lot of new warnings.  Happily they
seem to be mostly the valid kind, but it's going to cause a round of
churn for getting rid of them..

This is the really low-hanging fruit of removing a couple of zero-sized
arrays in some core code.  We have had a round of these patches before,
and we'll have many more coming, and there is nothing special about
these except that they were particularly trivial, and triggered more
warnings than most.

Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>pnp: Use list_for_each_entry() instead of open coding</title>
<updated>2020-05-20T06:17:09Z</updated>
<author>
<name>Jason Gunthorpe</name>
<email>jgg@mellanox.com</email>
</author>
<published>2020-04-14T15:10:50Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=294e9e42825aabe1de0a0baea6ae473fa7ec020b'/>
<id>urn:sha1:294e9e42825aabe1de0a0baea6ae473fa7ec020b</id>
<content type='text'>
commit 01b2bafe57b19d9119413f138765ef57990921ce upstream.

Aside from good practice, this avoids a warning from gcc 10:

./include/linux/kernel.h:997:3: warning: array subscript -31 is outside array bounds of ‘struct list_head[1]’ [-Warray-bounds]
  997 |  ((type *)(__mptr - offsetof(type, member))); })
      |  ~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
./include/linux/list.h:493:2: note: in expansion of macro ‘container_of’
  493 |  container_of(ptr, type, member)
      |  ^~~~~~~~~~~~
./include/linux/pnp.h:275:30: note: in expansion of macro ‘list_entry’
  275 | #define global_to_pnp_dev(n) list_entry(n, struct pnp_dev, global_list)
      |                              ^~~~~~~~~~
./include/linux/pnp.h:281:11: note: in expansion of macro ‘global_to_pnp_dev’
  281 |  (dev) != global_to_pnp_dev(&amp;pnp_global); \
      |           ^~~~~~~~~~~~~~~~~
arch/x86/kernel/rtc.c:189:2: note: in expansion of macro ‘pnp_for_each_dev’
  189 |  pnp_for_each_dev(dev) {

Because the common code doesn't cast the starting list_head to the
containing struct.

Signed-off-by: Jason Gunthorpe &lt;jgg@mellanox.com&gt;
[ rjw: Whitespace adjustments ]
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>blktrace: Protect q-&gt;blk_trace with RCU</title>
<updated>2020-05-20T06:17:03Z</updated>
<author>
<name>Jan Kara</name>
<email>jack@suse.cz</email>
</author>
<published>2020-02-06T14:28:12Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=7a35c8cbf2522e4f45d266dca95dacc71cf412ed'/>
<id>urn:sha1:7a35c8cbf2522e4f45d266dca95dacc71cf412ed</id>
<content type='text'>
commit c780e86dd48ef6467a1146cf7d0fe1e05a635039 upstream.

KASAN is reporting that __blk_add_trace() has a use-after-free issue
when accessing q-&gt;blk_trace. Indeed the switching of block tracing (and
thus eventual freeing of q-&gt;blk_trace) is completely unsynchronized with
the currently running tracing and thus it can happen that the blk_trace
structure is being freed just while __blk_add_trace() works on it.
Protect accesses to q-&gt;blk_trace by RCU during tracing and make sure we
wait for the end of RCU grace period when shutting down tracing. Luckily
that is rare enough event that we can afford that. Note that postponing
the freeing of blk_trace to an RCU callback should better be avoided as
it could have unexpected user visible side-effects as debugfs files
would be still existing for a short while block tracing has been shut
down.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=205711
CC: stable@vger.kernel.org
Reviewed-by: Chaitanya Kulkarni &lt;chaitanya.kulkarni@wdc.com&gt;
Reviewed-by: Ming Lei &lt;ming.lei@redhat.com&gt;
Tested-by: Ming Lei &lt;ming.lei@redhat.com&gt;
Reviewed-by: Bart Van Assche &lt;bvanassche@acm.org&gt;
Reported-by: Tristan Madani &lt;tristmd@gmail.com&gt;
Signed-off-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
[bwh: Backported to 4.14: adjust context]
Signed-off-by: Ben Hutchings &lt;ben.hutchings@codethink.co.uk&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>net: stricter validation of untrusted gso packets</title>
<updated>2020-05-20T06:16:56Z</updated>
<author>
<name>Willem de Bruijn</name>
<email>willemb@google.com</email>
</author>
<published>2020-05-04T16:48:54Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=a0c23ec2171f98e401504bb6b789410f1646a686'/>
<id>urn:sha1:a0c23ec2171f98e401504bb6b789410f1646a686</id>
<content type='text'>
[ Upstream commit 9274124f023b5c56dc4326637d4f787968b03607 ]

Syzkaller again found a path to a kernel crash through bad gso input:
a packet with transport header extending beyond skb_headlen(skb).

Tighten validation at kernel entry:

- Verify that the transport header lies within the linear section.

    To avoid pulling linux/tcp.h, verify just sizeof tcphdr.
    tcp_gso_segment will call pskb_may_pull (th-&gt;doff * 4) before use.

- Match the gso_type against the ip_proto found by the flow dissector.

Fixes: bfd5f4a3d605 ("packet: Add GSO/csum offload support.")
Reported-by: syzbot &lt;syzkaller@googlegroups.com&gt;
Signed-off-by: Willem de Bruijn &lt;willemb@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>mac80211: add ieee80211_is_any_nullfunc()</title>
<updated>2020-05-10T08:29:03Z</updated>
<author>
<name>Thomas Pedersen</name>
<email>thomas@adapt-ip.com</email>
</author>
<published>2020-01-14T05:59:40Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=1bfd4bed884d075f90793f297bc4ac09df3bd844'/>
<id>urn:sha1:1bfd4bed884d075f90793f297bc4ac09df3bd844</id>
<content type='text'>
commit 30b2f0be23fb40e58d0ad2caf8702c2a44cda2e1 upstream.

commit 08a5bdde3812 ("mac80211: consider QoS Null frames for STA_NULLFUNC_ACKED")
Fixed a bug where we failed to take into account a
nullfunc frame can be either non-QoS or QoS. It turns out
there is at least one more bug in
ieee80211_sta_tx_notify(), introduced in
commit 7b6ddeaf27ec ("mac80211: use QoS NDP for AP probing"),
where we forgot to check for the QoS variant and so
assumed the QoS nullfunc frame never went out

Fix this by adding a helper ieee80211_is_any_nullfunc()
which consolidates the check for non-QoS and QoS nullfunc
frames. Replace existing compound conditionals and add a
couple more missing checks for QoS variant.

Signed-off-by: Thomas Pedersen &lt;thomas@adapt-ip.com&gt;
Link: https://lore.kernel.org/r/20200114055940.18502-3-thomas@adapt-ip.com
Signed-off-by: Johannes Berg &lt;johannes.berg@intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>qed: Fix use after free in qed_chain_free</title>
<updated>2020-05-02T15:24:46Z</updated>
<author>
<name>Yuval Basson</name>
<email>ybason@marvell.com</email>
</author>
<published>2020-03-29T17:32:49Z</published>
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<id>urn:sha1:5b5a948a44bf78187636ce934e3f2e7bdb30ecf1</id>
<content type='text'>
commit 8063f761cd7c17fc1d0018728936e0c33a25388a upstream.

The qed_chain data structure was modified in
commit 1a4a69751f4d ("qed: Chain support for external PBL") to support
receiving an external pbl (due to iWARP FW requirements).
The pages pointed to by the pbl are allocated in qed_chain_alloc
and their virtual address are stored in an virtual addresses array to
enable accessing and freeing the data. The physical addresses however
weren't stored and were accessed directly from the external-pbl
during free.

Destroy-qp flow, leads to freeing the external pbl before the chain is
freed, when the chain is freed it tries accessing the already freed
external pbl, leading to a use-after-free. Therefore we need to store
the physical addresses in additional to the virtual addresses in a
new data structure.

Fixes: 1a4a69751f4d ("qed: Chain support for external PBL")
Signed-off-by: Michal Kalderon &lt;mkalderon@marvell.com&gt;
Signed-off-by: Yuval Bason &lt;ybason@marvell.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>KVM: Check validity of resolved slot when searching memslots</title>
<updated>2020-05-02T15:24:25Z</updated>
<author>
<name>Sean Christopherson</name>
<email>sean.j.christopherson@intel.com</email>
</author>
<published>2020-04-08T06:40:58Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=ba46d6dcee90f57964d446c281ef53dea027f42d'/>
<id>urn:sha1:ba46d6dcee90f57964d446c281ef53dea027f42d</id>
<content type='text'>
commit b6467ab142b708dd076f6186ca274f14af379c72 upstream.

Check that the resolved slot (somewhat confusingly named 'start') is a
valid/allocated slot before doing the final comparison to see if the
specified gfn resides in the associated slot.  The resolved slot can be
invalid if the binary search loop terminated because the search index
was incremented beyond the number of used slots.

This bug has existed since the binary search algorithm was introduced,
but went unnoticed because KVM statically allocated memory for the max
number of slots, i.e. the access would only be truly out-of-bounds if
all possible slots were allocated and the specified gfn was less than
the base of the lowest memslot.  Commit 36947254e5f98 ("KVM: Dynamically
size memslot array based on number of used slots") eliminated the "all
possible slots allocated" condition and made the bug embarrasingly easy
to hit.

Fixes: 9c1a5d38780e6 ("kvm: optimize GFN to memslot lookup with large slots amount")
Reported-by: syzbot+d889b59b2bb87d4047a2@syzkaller.appspotmail.com
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson &lt;sean.j.christopherson@intel.com&gt;
Message-Id: &lt;20200408064059.8957-2-sean.j.christopherson@intel.com&gt;
Reviewed-by: Cornelia Huck &lt;cohuck@redhat.com&gt;
Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>vmalloc: fix remap_vmalloc_range() bounds checks</title>
<updated>2020-05-02T15:24:21Z</updated>
<author>
<name>Jann Horn</name>
<email>jannh@google.com</email>
</author>
<published>2020-04-21T01:14:11Z</published>
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<id>urn:sha1:e5de393402985a04fcd6980d3701759e31e2cfff</id>
<content type='text'>
commit bdebd6a2831b6fab69eb85cee74a8ba77f1a1cc2 upstream.

remap_vmalloc_range() has had various issues with the bounds checks it
promises to perform ("This function checks that addr is a valid
vmalloc'ed area, and that it is big enough to cover the vma") over time,
e.g.:

 - not detecting pgoff&lt;&lt;PAGE_SHIFT overflow

 - not detecting (pgoff&lt;&lt;PAGE_SHIFT)+usize overflow

 - not checking whether addr and addr+(pgoff&lt;&lt;PAGE_SHIFT) are the same
   vmalloc allocation

 - comparing a potentially wildly out-of-bounds pointer with the end of
   the vmalloc region

In particular, since commit fc9702273e2e ("bpf: Add mmap() support for
BPF_MAP_TYPE_ARRAY"), unprivileged users can cause kernel null pointer
dereferences by calling mmap() on a BPF map with a size that is bigger
than the distance from the start of the BPF map to the end of the
address space.

This could theoretically be used as a kernel ASLR bypass, by using
whether mmap() with a given offset oopses or returns an error code to
perform a binary search over the possible address range.

To allow remap_vmalloc_range_partial() to verify that addr and
addr+(pgoff&lt;&lt;PAGE_SHIFT) are in the same vmalloc region, pass the offset
to remap_vmalloc_range_partial() instead of adding it to the pointer in
remap_vmalloc_range().

In remap_vmalloc_range_partial(), fix the check against
get_vm_area_size() by using size comparisons instead of pointer
comparisons, and add checks for pgoff.

Fixes: 833423143c3a ("[PATCH] mm: introduce remap_vmalloc_range()")
Signed-off-by: Jann Horn &lt;jannh@google.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: stable@vger.kernel.org
Cc: Alexei Starovoitov &lt;ast@kernel.org&gt;
Cc: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Cc: Martin KaFai Lau &lt;kafai@fb.com&gt;
Cc: Song Liu &lt;songliubraving@fb.com&gt;
Cc: Yonghong Song &lt;yhs@fb.com&gt;
Cc: Andrii Nakryiko &lt;andriin@fb.com&gt;
Cc: John Fastabend &lt;john.fastabend@gmail.com&gt;
Cc: KP Singh &lt;kpsingh@chromium.org&gt;
Link: http://lkml.kernel.org/r/20200415222312.236431-1-jannh@google.com
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>overflow.h: Add arithmetic shift helper</title>
<updated>2020-05-02T15:24:21Z</updated>
<author>
<name>Jason Gunthorpe</name>
<email>jgg@mellanox.com</email>
</author>
<published>2018-08-01T21:25:39Z</published>
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<id>urn:sha1:334c43f8d69fa5aa6487157b927ed9146e40786e</id>
<content type='text'>
commit 0c66847793d1982d1083dc6f7adad60fa265ce9c upstream.

Add shift_overflow() helper to assist driver authors in ensuring that
shift operations don't cause overflows or other odd conditions.

Signed-off-by: Jason Gunthorpe &lt;jgg@mellanox.com&gt;
Signed-off-by: Leon Romanovsky &lt;leonro@mellanox.com&gt;
[kees: tweaked comments and commit log, dropped unneeded assignment]
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
</feed>
