linux-stable.git/include/uapi/linux, branch v6.18.26

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

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

dpll: add phase-adjust-gran pin attribute

2026-02-26T22:59:22+00:00

[ Upstream commit 30176bf7c871681df506f3165ffe76ec462db991 ]

Phase-adjust values are currently limited by a min-max range. Some
hardware requires, for certain pin types, that values be multiples of
a specific granularity, as in the zl3073x driver.

Add a `phase-adjust-gran` pin attribute and an appropriate field in
dpll_pin_properties. If set by the driver, use its value to validate
user-provided phase-adjust values.

Reviewed-by: Michal Schmidt 
Reviewed-by: Petr Oros 
Tested-by: Prathosh Satish 
Signed-off-by: Ivan Vecera 
Reviewed-by: Jiri Pirko 
Reviewed-by: Arkadiusz Kubalewski 
Link: https://patch.msgid.link/20251029153207.178448-2-ivecera@redhat.com
Signed-off-by: Jakub Kicinski 
Stable-dep-of: 5d41f95f5d0b ("dpll: zl3073x: Fix output pin phase adjustment sign")
Signed-off-by: Sasha Levin

NFS: NFSERR_INVAL is not defined by NFSv2

2026-02-26T22:59:18+00:00

[ Upstream commit 0ac903d1bfdce8ff40657c2b7d996947b72b6645 ]

A documenting comment in include/uapi/linux/nfs.h claims incorrectly
that NFSv2 defines NFSERR_INVAL. There is no such definition in either
RFC 1094 or https://pubs.opengroup.org/onlinepubs/9629799/chap7.htm

NFS3ERR_INVAL is introduced in RFC 1813.

NFSD returns NFSERR_INVAL for PROC_GETACL, which has no
specification (yet).

However, nfsd_map_status() maps nfserr_symlink and nfserr_wrong_type
to nfserr_inval, which does not align with RFC 1094. This logic was
introduced only recently by commit 438f81e0e92a ("nfsd: move error
choice for incorrect object types to version-specific code."). Given
that we have no INVAL or SERVERFAULT status in NFSv2, probably the
only choice is NFSERR_IO.

Fixes: 438f81e0e92a ("nfsd: move error choice for incorrect object types to version-specific code.")
Reviewed-by: NeilBrown 
Reviewed-by: Jeff Layton 
Signed-off-by: Chuck Lever 
Signed-off-by: Sasha Levin