xen-netback: properly sync TX responses

commit 7b55984c96ffe9e236eb9c82a2196e0b1f84990d upstream.

Invoking the make_tx_response() / push_tx_responses() pair with no lock
held would be acceptable on

xen-netback: properly sync TX responses

commit 7b55984c96ffe9e236eb9c82a2196e0b1f84990d upstream.

Invoking the make_tx_response() / push_tx_responses() pair with no lock
held would be acceptable only if all such invocations happened from the
same context (NAPI instance or dealloc thread). Since this isn't the
case, and since the interface "spec" also doesn't demand that multicast
operations may only be performed with no in-flight transmits,
MCAST_{ADD,DEL} processing also needs to acquire the response lock
around the invocations.

To prevent similar mistakes going forward, "downgrade" the present
functions to private helpers of just the two remaining ones using them
directly, with no forward declarations anymore. This involves renaming
what so far was make_tx_response(), for the new function of that name
to serve the new (wrapper) purpose.

While there,
- constify the txp parameters,
- correct xenvif_idx_release()'s status parameter's type,
- rename {,_}make_tx_response()'s status parameters for consistency with
xenvif_idx_release()'s.

Fixes: 210c34dcd8d9 ("xen-netback: add support for multicast control")
Cc: stable@vger.kernel.org
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Link: https://lore.kernel.org/r/980c6c3d-e10e-4459-8565-e8fbde122f00@suse.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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xen-netback: don't produce zero-size SKB frags

commit c7ec4f2d684e17d69bbdd7c4324db0ef5daac26a upstream.

While frontends may submit zero-size requests (wasting a precious slot),
core networking cod

xen-netback: don't produce zero-size SKB frags

commit c7ec4f2d684e17d69bbdd7c4324db0ef5daac26a upstream.

While frontends may submit zero-size requests (wasting a precious slot),
core networking code as of at least 3ece782693c4b ("sock: skb_copy_ubufs
support for compound pages") can't deal with SKBs when they have all
zero-size fragments. Respond to empty requests right when populating
fragments; all further processing is fragment based and hence won't
encounter these empty requests anymore.

In a way this should have been that way from the beginning: When no data
is to be transferred for a particular request, there's not even a point
in validating the respective grant ref. That's no different from e.g.
passing NULL into memcpy() when at the same time the size is 0.

This is XSA-448 / CVE-2023-46838.

Cc: stable@vger.kernel.org
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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xen/netback: Fix buffer overrun triggered by unusual packet

It is possible that a guest can send a packet that contains a head + 18
slots and yet has a len <= XEN_NETBACK_TX_COPY_LEN. This causes nr

xen/netback: Fix buffer overrun triggered by unusual packet

It is possible that a guest can send a packet that contains a head + 18
slots and yet has a len <= XEN_NETBACK_TX_COPY_LEN. This causes nr_slots
to underflow in xenvif_get_requests() which then causes the subsequent
loop's termination condition to be wrong, causing a buffer overrun of
queue->tx_map_ops.

Rework the code to account for the extra frag_overflow slots.

This is CVE-2023-34319 / XSA-432.

Fixes: ad7f402ae4f4 ("xen/netback: Ensure protocol headers don't fall in the non-linear area")
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Reviewed-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Juergen Gross <jgross@suse.com>

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xen/netback: Pass (void *) to virt_to_page()

virt_to_page() takes a virtual address as argument but
the driver passes an unsigned long, which works because
the target platform(s) uses polymorphic ma

xen/netback: Pass (void *) to virt_to_page()

virt_to_page() takes a virtual address as argument but
the driver passes an unsigned long, which works because
the target platform(s) uses polymorphic macros to calculate
the page.

Since many architectures implement virt_to_pfn() as
a macro, this function becomes polymorphic and accepts both a
(unsigned long) and a (void *).

Fix this up by an explicit (void *) cast.

Cc: Wei Liu <wei.liu@kernel.org>
Cc: Paul Durrant <paul@xen.org>
Cc: xen-devel@lists.xenproject.org
Cc: netdev@vger.kernel.org
Acked-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

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net: introduce and use skb_frag_fill_page_desc()

Most users use __skb_frag_set_page()/skb_frag_off_set()/
skb_frag_size_set() to fill the page desc for a skb frag.

Introduce skb_frag_fill_page_desc

net: introduce and use skb_frag_fill_page_desc()

Most users use __skb_frag_set_page()/skb_frag_off_set()/
skb_frag_size_set() to fill the page desc for a skb frag.

Introduce skb_frag_fill_page_desc() to do that.

net/bpf/test_run.c does not call skb_frag_off_set() to
set the offset, "copy_from_user(page_address(page), ...)"
and 'shinfo' being part of the 'data' kzalloced in
bpf_test_init() suggest that it is assuming offset to be
initialized as zero, so call skb_frag_fill_page_desc()
with offset being zero for this case.

Also, skb_frag_set_page() is not used anymore, so remove
it.

Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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xen/netback: use same error messages for same errors

Issue the same error message in case an illegal page boundary crossing
has been detected in both cases where this is tested.

Suggested-by: Jan B

xen/netback: use same error messages for same errors

Issue the same error message in case an illegal page boundary crossing
has been detected in both cases where this is tested.

Suggested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Link: https://lore.kernel.org/r/20230329080259.14823-1-jgross@suse.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

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xen/netback: remove not needed test in xenvif_tx_build_gops()

The tests for the number of grant mapping or copy operations reaching
the array size of the operations buffer at the end of the main loo

xen/netback: remove not needed test in xenvif_tx_build_gops()

The tests for the number of grant mapping or copy operations reaching
the array size of the operations buffer at the end of the main loop in
xenvif_tx_build_gops() isn't needed.

The loop can handle at maximum MAX_PENDING_REQS transfer requests, as
XEN_RING_NR_UNCONSUMED_REQUESTS() is taking unsent responses into
consideration, too.

Remove the tests.

Suggested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

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xen/netback: don't do grant copy across page boundary

Fix xenvif_get_requests() not to do grant copy operations across local
page boundaries. This requires to double the maximum number of copy
opera

xen/netback: don't do grant copy across page boundary

Fix xenvif_get_requests() not to do grant copy operations across local
page boundaries. This requires to double the maximum number of copy
operations per queue, as each copy could now be split into 2.

Make sure that struct xenvif_tx_cb doesn't grow too large.

Cc: stable@vger.kernel.org
Fixes: ad7f402ae4f4 ("xen/netback: Ensure protocol headers don't fall in the non-linear area")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

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xen-netback: remove unused variables pending_idx and index

building with gcc and W=1 reports
drivers/net/xen-netback/netback.c:886:21: error: variable
‘pending_idx’ set but not used [-Werror=unuse

xen-netback: remove unused variables pending_idx and index

building with gcc and W=1 reports
drivers/net/xen-netback/netback.c:886:21: error: variable
‘pending_idx’ set but not used [-Werror=unused-but-set-variable]
886 | u16 pending_idx;
| ^~~~~~~~~~~

pending_idx is not used so remove it. Since index was only
used to set pending_idx, remove index as well.

Signed-off-by: Tom Rix <trix@redhat.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20230226163429.2351600-1-trix@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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xen/netback: fix build warning

Commit ad7f402ae4f4 ("xen/netback: Ensure protocol headers don't fall in
the non-linear area") introduced a (valid) build warning. There have
even been reports of this

xen/netback: fix build warning

Commit ad7f402ae4f4 ("xen/netback: Ensure protocol headers don't fall in
the non-linear area") introduced a (valid) build warning. There have
even been reports of this problem breaking networking of Xen guests.

Fixes: ad7f402ae4f4 ("xen/netback: Ensure protocol headers don't fall in the non-linear area")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Tested-by: Jason Andryuk <jandryuk@gmail.com>
Signed-off-by: Juergen Gross <jgross@suse.com>

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xen/netback: Ensure protocol headers don't fall in the non-linear area

In some cases, the frontend may send a packet where the protocol headers
are spread across multiple slots. This would result in

xen/netback: Ensure protocol headers don't fall in the non-linear area

In some cases, the frontend may send a packet where the protocol headers
are spread across multiple slots. This would result in netback creating
an skb where the protocol headers spill over into the non-linear area.
Some drivers and NICs don't handle this properly resulting in an
interface reset or worse.

This issue was introduced by the removal of an unconditional skb pull in
the tx path to improve performance. Fix this without reintroducing the
pull by setting up grant copy ops for as many slots as needed to reach
the XEN_NETBACK_TX_COPY_LEN size. Adjust the rest of the code to handle
multiple copy operations per skb.

This is XSA-423 / CVE-2022-3643.

Fixes: 7e5d7753956b ("xen-netback: remove unconditional __pskb_pull_tail() in guest Tx path")
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Signed-off-by: Juergen Gross <jgross@suse.com>

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xen/netback: use struct ubuf_info_msgzc

struct ubuf_info will be changed, use ubuf_info_msgzc instead.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Acked-by: Paolo Abeni <pabeni@redhat.co

xen/netback: use struct ubuf_info_msgzc

struct ubuf_info will be changed, use ubuf_info_msgzc instead.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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net: add skb_[inner_]tcp_all_headers helpers

Most drivers use "skb_transport_offset(skb) + tcp_hdrlen(skb)"
to compute headers length for a TCP packet, but others
use more convoluted (but equivalent

net: add skb_[inner_]tcp_all_headers helpers

Most drivers use "skb_transport_offset(skb) + tcp_hdrlen(skb)"
to compute headers length for a TCP packet, but others
use more convoluted (but equivalent) ways.

Add skb_tcp_all_headers() and skb_inner_tcp_all_headers()
helpers to harmonize this a bit.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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xen/netback: do some code cleanup

Remove some unused macros and functions, make local functions static.

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wei.liu@kernel.org>
Link: h

xen/netback: do some code cleanup

Remove some unused macros and functions, make local functions static.

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wei.liu@kernel.org>
Link: https://lore.kernel.org/r/20220608043726.9380-1-jgross@suse.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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xen/netback: fix incorrect usage of RING_HAS_UNCONSUMED_REQUESTS()

Commit 6fac592cca60 ("xen: update ring.h") missed to fix one use case
of RING_HAS_UNCONSUMED_REQUESTS().

Reported-by: Jan Beulich

xen/netback: fix incorrect usage of RING_HAS_UNCONSUMED_REQUESTS()

Commit 6fac592cca60 ("xen: update ring.h") missed to fix one use case
of RING_HAS_UNCONSUMED_REQUESTS().

Reported-by: Jan Beulich <jbeulich@suse.com>
Fixes: 6fac592cca60 ("xen: update ring.h")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Wei Liu <wei.liu@kernel.org>
Link: https://lore.kernel.org/r/20220530113459.20124-1-jgross@suse.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

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xen-netback: Remove redundant initialization of variable err

The variable err is being initialized with a value that is never read, it
is being updated immediately afterwards. The assignment is redu

xen-netback: Remove redundant initialization of variable err

The variable err is being initialized with a value that is never read, it
is being updated immediately afterwards. The assignment is redundant and
can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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xen-netback: correct success/error reporting for the SKB-with-fraglist case

When re-entering the main loop of xenvif_tx_check_gop() a 2nd time, the
special considerations for the head of the SKB no

xen-netback: correct success/error reporting for the SKB-with-fraglist case

When re-entering the main loop of xenvif_tx_check_gop() a 2nd time, the
special considerations for the head of the SKB no longer apply. Don't
mistakenly report ERROR to the frontend for the first entry in the list,
even if - from all I can tell - this shouldn't matter much as the overall
transmit will need to be considered failed anyway.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

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xen-netback: respect gnttab_map_refs()'s return value

Commit 3194a1746e8a ("xen-netback: don't "handle" error by BUG()")
dropped respective a BUG_ON() without noticing that with this the
variable's

xen-netback: respect gnttab_map_refs()'s return value

Commit 3194a1746e8a ("xen-netback: don't "handle" error by BUG()")
dropped respective a BUG_ON() without noticing that with this the
variable's value wouldn't be consumed anymore. With gnttab_set_map_op()
setting all status fields to a non-zero value, in case of an error no
slot should have a status of GNTST_okay (zero).

This is part of XSA-367.

Cc: <stable@vger.kernel.org>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/d933f495-619a-0086-5fb4-1ec3cf81a8fc@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>

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xen-netback: use local var in xenvif_tx_check_gop() instead of re-calculating

shinfo already holds the result of skb_shinfo(skb) at this point - no
need to re-invoke the construct even twice.

Signe

xen-netback: use local var in xenvif_tx_check_gop() instead of re-calculating

shinfo already holds the result of skb_shinfo(skb) at this point - no
need to re-invoke the construct even twice.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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xen-netback: don't "handle" error by BUG()

In particular -ENOMEM may come back here, from set_foreign_p2m_mapping().
Don't make problems worse, the more that handling elsewhere (together
with map's

xen-netback: don't "handle" error by BUG()

In particular -ENOMEM may come back here, from set_foreign_p2m_mapping().
Don't make problems worse, the more that handling elsewhere (together
with map's status fields now indicating whether a mapping wasn't even
attempted, and hence has to be considered failed) doesn't require this
odd way of dealing with errors.

This is part of XSA-362.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: stable@vger.kernel.org
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>

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skbuff: Add skb parameter to the ubuf zerocopy callback

Add an optional skb parameter to the zerocopy callback parameter,
which is passed down from skb_zcopy_clear(). This gives access
to the origi

skbuff: Add skb parameter to the ubuf zerocopy callback

Add an optional skb parameter to the zerocopy callback parameter,
which is passed down from skb_zcopy_clear(). This gives access
to the original skb, which is needed for upcoming RX zero-copy
error handling.

Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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xen-netback: respect gnttab_map_refs()'s return value

commit 2991397d23ec597405b116d96de3813420bdcbc3 upstream.

Commit 3194a1746e8a ("xen-netback: don't "handle" error by BUG()")
dropped respective

xen-netback: respect gnttab_map_refs()'s return value

commit 2991397d23ec597405b116d96de3813420bdcbc3 upstream.

Commit 3194a1746e8a ("xen-netback: don't "handle" error by BUG()")
dropped respective a BUG_ON() without noticing that with this the
variable's value wouldn't be consumed anymore. With gnttab_set_map_op()
setting all status fields to a non-zero value, in case of an error no
slot should have a status of GNTST_okay (zero).

This is part of XSA-367.

Cc: <stable@vger.kernel.org>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/d933f495-619a-0086-5fb4-1ec3cf81a8fc@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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xen-netback: don't "handle" error by BUG()

commit 3194a1746e8aabe86075fd3c5e7cf1f4632d7f16 upstream.

In particular -ENOMEM may come back here, from set_foreign_p2m_mapping().
Don't make problems wo

xen-netback: don't "handle" error by BUG()

commit 3194a1746e8aabe86075fd3c5e7cf1f4632d7f16 upstream.

In particular -ENOMEM may come back here, from set_foreign_p2m_mapping().
Don't make problems worse, the more that handling elsewhere (together
with map's status fields now indicating whether a mapping wasn't even
attempted, and hence has to be considered failed) doesn't require this
odd way of dealing with errors.

This is part of XSA-362.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: stable@vger.kernel.org
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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xen/netback: use lateeoi irq binding

In order to reduce the chance for the system becoming unresponsive due
to event storms triggered by a misbehaving netfront use the lateeoi
irq binding for netbac

xen/netback: use lateeoi irq binding

In order to reduce the chance for the system becoming unresponsive due
to event storms triggered by a misbehaving netfront use the lateeoi
irq binding for netback and unmask the event channel only just before
going to sleep waiting for new events.

Make sure not to issue an EOI when none is pending by introducing an
eoi_pending element to struct xenvif_queue.

When no request has been consumed set the spurious flag when sending
the EOI for an interrupt.

This is part of XSA-332.

Cc: stable@vger.kernel.org
Reported-by: Julien Grall <julien@xen.org>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Wei Liu <wl@xen.org>

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xen networking: add XDP offset adjustment to xen-netback

the patch basically adds the offset adjustment and netfront
state reading to make XDP work on netfront side.

Reviewed-by: Paul Durrant <paul

xen networking: add XDP offset adjustment to xen-netback

the patch basically adds the offset adjustment and netfront
state reading to make XDP work on netfront side.

Reviewed-by: Paul Durrant <paul@xen.org>
Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

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