linux-stable.git/include/uapi, branch v6.18.32

io_uring/kbuf: support min length left for incremental buffers

2026-05-14T13:30:24+00:00

Commit 7deba791ad495ce1d7921683f4f7d1190fa210d1 upstream.

Incrementally consumed buffer rings are generally fully consumed, but
it's quite possible that the application has a minimum size it needs to
meet to avoid truncation. Currently that minimum limit is 1 byte, but
this should be a setting that is the hands of the application. For
recvmsg multishot, a prime use case for incrementally consumed buffers,
the application may get spurious -EFAULT returned at the end of an
incrementally consumed buffer, as less space is available than the
headers need.

Grab a u32 field in struct io_uring_buf_reg, which the application can
use to inform the kernel of the minimum size that should be available
in an incrementally consumed buffer. If less than that is available,
the current buffer is fully processed and the next one will be picked.

Cc: stable@vger.kernel.org
Fixes: ae98dbf43d75 ("io_uring/kbuf: add support for incremental buffer consumption")
Link: https://github.com/axboe/liburing/issues/1433
Signed-off-by: Martin Michaelis 
[axboe: write commit message, change io_buffer_list member name]
Reviewed-by: Gabriel Krisman Bertazi 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

KVM: x86: Use __DECLARE_FLEX_ARRAY() for UAPI structures with VLAs

2026-04-22T11:22:31+00:00

[ Upstream commit 2619da73bb2f10d88f7e1087125c40144fdf0987 ]

Commit 94dfc73e7cf4 ("treewide: uapi: Replace zero-length arrays with
flexible-array members") broke the userspace API for C++.

These structures ending in VLAs are typically a *header*, which can be
followed by an arbitrary number of entries. Userspace typically creates
a larger structure with some non-zero number of entries, for example in
QEMU's kvm_arch_get_supported_msr_feature():

    struct {
        struct kvm_msrs info;
        struct kvm_msr_entry entries[1];
    } msr_data = {};

While that works in C, it fails in C++ with an error like:
 flexible array member 'kvm_msrs::entries' not at end of 'struct msr_data'

Fix this by using __DECLARE_FLEX_ARRAY() for the VLA, which uses [0]
for C++ compilation.

Fixes: 94dfc73e7cf4 ("treewide: uapi: Replace zero-length arrays with flexible-array members")
Cc: stable@vger.kernel.org
Signed-off-by: David Woodhouse 
Link: https://patch.msgid.link/3abaf6aefd6e5efeff3b860ac38421d9dec908db.camel@infradead.org
[sean: tag for stable@]
Signed-off-by: Sean Christopherson 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

KVM: Remove subtle "struct kvm_stats_desc" pseudo-overlay

2026-04-22T11:22:30+00:00

[ Upstream commit da142f3d373a6ddaca0119615a8db2175ddc4121 ]

Remove KVM's internal pseudo-overlay of kvm_stats_desc, which subtly
aliases the flexible name[] in the uAPI definition with a fixed-size array
of the same name.  The unusual embedded structure results in compiler
warnings due to -Wflex-array-member-not-at-end, and also necessitates an
extra level of dereferencing in KVM.  To avoid the "overlay", define the
uAPI structure to have a fixed-size name when building for the kernel.

Opportunistically clean up the indentation for the stats macros, and
replace spaces with tabs.

No functional change intended.

Reported-by: Gustavo A. R. Silva 
Closes: https://lore.kernel.org/all/aPfNKRpLfhmhYqfP@kspp
Acked-by: Marc Zyngier 
Acked-by: Christian Borntraeger 
[..]
Acked-by: Anup Patel 
Reviewed-by: Bibo Mao 
Acked-by: Gustavo A. R. Silva 
Link: https://patch.msgid.link/20251205232655.445294-1-seanjc@google.com
Signed-off-by: Sean Christopherson 
Stable-dep-of: 2619da73bb2f ("KVM: x86: Use __DECLARE_FLEX_ARRAY() for UAPI structures with VLAs")
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

netfilter: ctnetlink: use netlink policy range checks

2026-04-02T11:23:10+00:00

[ Upstream commit 8f15b5071b4548b0aafc03b366eb45c9c6566704 ]

Replace manual range and mask validations with netlink policy
annotations in ctnetlink code paths, so that the netlink core rejects
invalid values early and can generate extack errors.

- CTA_PROTOINFO_TCP_STATE: reject values > TCP_CONNTRACK_SYN_SENT2 at
  policy level, removing the manual >= TCP_CONNTRACK_MAX check.
- CTA_PROTOINFO_TCP_WSCALE_ORIGINAL/REPLY: reject values > TCP_MAX_WSCALE
  (14). The normal TCP option parsing path already clamps to this value,
  but the ctnetlink path accepted 0-255, causing undefined behavior when
  used as a u32 shift count.
- CTA_FILTER_ORIG_FLAGS/REPLY_FLAGS: use NLA_POLICY_MASK with
  CTA_FILTER_F_ALL, removing the manual mask checks.
- CTA_EXPECT_FLAGS: use NLA_POLICY_MASK with NF_CT_EXPECT_MASK, adding
  a new mask define grouping all valid expect flags.

Extracted from a broader nf-next patch by Florian Westphal, scoped to
ctnetlink for the fixes tree.

Fixes: c8e2078cfe41 ("[NETFILTER]: ctnetlink: add support for internal tcp connection tracking flags handling")
Signed-off-by: David Carlier 
Co-developed-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

dma-buf: Include ioctl.h in UAPI header

2026-04-02T11:22:59+00:00

[ Upstream commit a116bac87118903925108e57781bbfc7a7eea27b ]

include/uapi/linux/dma-buf.h uses several macros from ioctl.h to define
its ioctl commands. However, it does not include ioctl.h itself. So,
if userspace source code tries to include the dma-buf.h file without
including ioctl.h, it can result in build failures.

Therefore, include ioctl.h in the dma-buf UAPI header.

Signed-off-by: Isaac J. Manjarres 
Reviewed-by: T.J. Mercier 
Reviewed-by: Christian König 
Signed-off-by: Christian König 
Link: https://lore.kernel.org/r/20260303002309.1401849-1-isaacmanjarres@google.com
Signed-off-by: Sasha Levin

PCI: Correct PCI_CAP_EXP_ENDPOINT_SIZEOF_V2 value

2026-03-12T11:09:22+00:00

[ Upstream commit 39195990e4c093c9eecf88f29811c6de29265214 ]

fb82437fdd8c ("PCI: Change capability register offsets to hex") incorrectly
converted the PCI_CAP_EXP_ENDPOINT_SIZEOF_V2 value from decimal 52 to hex
0x32:

  -#define PCI_CAP_EXP_ENDPOINT_SIZEOF_V2 52      /* v2 endpoints with link end here */
  +#define PCI_CAP_EXP_ENDPOINT_SIZEOF_V2 0x32    /* end of v2 EPs w/ link */

This broke PCI capabilities in a VMM because subsequent ones weren't
DWORD-aligned.

Change PCI_CAP_EXP_ENDPOINT_SIZEOF_V2 to the correct value of 0x34.

fb82437fdd8c was from Baruch Siach , but this was not
Baruch's fault; it's a mistake I made when applying the patch.

Fixes: fb82437fdd8c ("PCI: Change capability register offsets to hex")
Reported-by: David Woodhouse 
Closes: https://lore.kernel.org/all/3ae392a0158e9d9ab09a1d42150429dd8ca42791.camel@infradead.org
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Krzysztof Wilczyński 
Signed-off-by: Sasha Levin

drm/fourcc: fix plane order for 10/12/16-bit YCbCr formats

2026-03-12T11:09:09+00:00

[ Upstream commit e9e0b48cd15b46dcb2bbc165f6b0fee698b855d6 ]

The short comments had the correct order, but the long comments
had the planes reversed.

Fixes: 2271e0a20ef7 ("drm: drm_fourcc: add 10/12/16bit software decoder YCbCr formats")
Signed-off-by: Simon Ser 
Reviewed-by: Daniel Stone 
Reviewed-by: Robert Mader 
Link: https://patch.msgid.link/20260208224718.57199-1-contact@emersion.fr
Signed-off-by: Sasha Levin

include: uapi: netfilter_bridge.h: Cover for musl libc

2026-03-04T12:20:39+00:00

[ Upstream commit 4edd4ba71ce0df015303dba75ea9d20d1a217546 ]

Musl defines its own struct ethhdr and thus defines __UAPI_DEF_ETHHDR to
zero. To avoid struct redefinition errors, user space is therefore
supposed to include netinet/if_ether.h before (or instead of)
linux/if_ether.h. To relieve them from this burden, include the libc
header here if not building for kernel space.

Reported-by: Alyssa Ross 
Suggested-by: Florian Westphal 
Signed-off-by: Phil Sutter 
Signed-off-by: Florian Westphal 
Signed-off-by: Sasha Levin

virt: vbox: uapi: Mark inner unions in packed structs as packed

2026-03-04T12:20:00+00:00

[ Upstream commit c25d01e1c4f2d43f47af87c00e223f5ca7c71792 ]

The unpacked unions within a packed struct generates alignment warnings
on clang for 32-bit ARM:

./usr/include/linux/vbox_vmmdev_types.h:239:4: error: field u within 'struct vmmdev_hgcm_function_parameter32'
  is less aligned than 'union (unnamed union at ./usr/include/linux/vbox_vmmdev_types.h:223:2)'
  and is usually due to 'struct vmmdev_hgcm_function_parameter32' being packed,
  which can lead to unaligned accesses [-Werror,-Wunaligned-access]
     239 |         } u;
         |           ^

./usr/include/linux/vbox_vmmdev_types.h:254:6: error: field u within
  'struct vmmdev_hgcm_function_parameter64::(anonymous union)::(unnamed at ./usr/include/linux/vbox_vmmdev_types.h:249:3)'
  is less aligned than 'union (unnamed union at ./usr/include/linux/vbox_vmmdev_types.h:251:4)' and is usually due to
  'struct vmmdev_hgcm_function_parameter64::(anonymous union)::(unnamed at ./usr/include/linux/vbox_vmmdev_types.h:249:3)'
  being packed, which can lead to unaligned accesses [-Werror,-Wunaligned-access]

With the recent changes to compile-test the UAPI headers in more cases,
these warning in combination with CONFIG_WERROR breaks the build.

Fix the warnings.

Reported-by: kernel test robot 
Closes: https://lore.kernel.org/oe-kbuild-all/202512140314.DzDxpIVn-lkp@intel.com/
Reported-by: Nathan Chancellor 
Closes: https://lore.kernel.org/linux-kbuild/20260110-uapi-test-disable-headers-arm-clang-unaligned-access-v1-1-b7b0fa541daa@kernel.org/
Suggested-by: Arnd Bergmann 
Link: https://lore.kernel.org/linux-kbuild/29b2e736-d462-45b7-a0a9-85f8d8a3de56@app.fastmail.com/
Signed-off-by: Thomas Weißschuh 
Tested-by: Nicolas Schier 
Reviewed-by: Nicolas Schier 
Acked-by: Greg Kroah-Hartman 
Link: https://patch.msgid.link/20260115-kbuild-alignment-vbox-v1-2-076aed1623ff@linutronix.de
Signed-off-by: Nathan Chancellor 
Signed-off-by: Sasha Levin

hyper-v: Mark inner union in hv_kvp_exchg_msg_value as packed

2026-03-04T12:20:00+00:00

[ Upstream commit 1e5271393d777f6159d896943b4c44c4f3ecff52 ]

The unpacked union within a packed struct generates alignment warnings
on clang for 32-bit ARM:

./usr/include/linux/hyperv.h:361:2: error: field  within 'struct hv_kvp_exchg_msg_value'
  is less aligned than 'union hv_kvp_exchg_msg_value::(anonymous at ./usr/include/linux/hyperv.h:361:2)'
  and is usually due to 'struct hv_kvp_exchg_msg_value' being packed,
  which can lead to unaligned accesses [-Werror,-Wunaligned-access]
     361 |         union {
         |         ^

With the recent changes to compile-test the UAPI headers in more cases,
this warning in combination with CONFIG_WERROR breaks the build.

Fix the warning.

Reported-by: kernel test robot 
Closes: https://lore.kernel.org/oe-kbuild-all/202512140314.DzDxpIVn-lkp@intel.com/
Reported-by: Nathan Chancellor 
Closes: https://lore.kernel.org/linux-kbuild/20260110-uapi-test-disable-headers-arm-clang-unaligned-access-v1-1-b7b0fa541daa@kernel.org/
Suggested-by: Arnd Bergmann 
Link: https://lore.kernel.org/linux-kbuild/29b2e736-d462-45b7-a0a9-85f8d8a3de56@app.fastmail.com/
Signed-off-by: Thomas Weißschuh 
Acked-by: Wei Liu (Microsoft) 
Tested-by: Nicolas Schier 
Reviewed-by: Nicolas Schier 
Acked-by: Greg Kroah-Hartman 
Link: https://patch.msgid.link/20260115-kbuild-alignment-vbox-v1-1-076aed1623ff@linutronix.de
Signed-off-by: Nathan Chancellor 
Signed-off-by: Sasha Levin