linux-stable.git/include/linux, branch v5.15.211 Linux kernel stable tree ring-buffer: Remove ring_buffer_read_prepare_sync() 2026-07-04T11:39:39+00:00 Bjoern Doebel doebel@amazon.de 2026-06-30T06:03:21+00:00 d842d74ec960fe9b829102b81503bbf4071de855 [ Upstream commit 119a5d573622ae90ba730d18acfae9bb75d77b9a ] When the ring buffer was first introduced, reading the non-consuming "trace" file required disabling the writing of the ring buffer. To make sure the writing was fully disabled before iterating the buffer with a non-consuming read, it would set the disable flag of the buffer and then call an RCU synchronization to make sure all the buffers were synchronized. The function ring_buffer_read_start() originally would initialize the iterator and call an RCU synchronization, but this was for each individual per CPU buffer where this would get called many times on a machine with many CPUs before the trace file could be read. The commit 72c9ddfd4c5bf ("ring-buffer: Make non-consuming read less expensive with lots of cpus.") separated ring_buffer_read_start into ring_buffer_read_prepare(), ring_buffer_read_sync() and then ring_buffer_read_start() to allow each of the per CPU buffers to be prepared, call the read_buffer_read_sync() once, and then the ring_buffer_read_start() for each of the CPUs which made things much faster. The commit 1039221cc278 ("ring-buffer: Do not disable recording when there is an iterator") removed the requirement of disabling the recording of the ring buffer in order to iterate it, but it did not remove the synchronization that was happening that was required to wait for all the buffers to have no more writers. It's now OK for the buffers to have writers and no synchronization is needed. Remove the synchronization and put back the interface for the ring buffer iterator back before commit 72c9ddfd4c5bf was applied. Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/20250630180440.3eabb514@batman.local.home Reported-by: David Howells <dhowells@redhat.com> Fixes: 1039221cc278 ("ring-buffer: Do not disable recording when there is an iterator") Tested-by: David Howells <dhowells@redhat.com> Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Assisted-by: Kiro:claude-opus-4.8 [doebel@amazon.de: move patch section using guard() macro into a separate block to address declaration after statement warning.] Signed-off-by: Bjoern Doebel <doebel@amazon.de> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 119a5d573622ae90ba730d18acfae9bb75d77b9a ]

When the ring buffer was first introduced, reading the non-consuming
"trace" file required disabling the writing of the ring buffer. To make
sure the writing was fully disabled before iterating the buffer with a
non-consuming read, it would set the disable flag of the buffer and then
call an RCU synchronization to make sure all the buffers were
synchronized.

The function ring_buffer_read_start() originally  would initialize the
iterator and call an RCU synchronization, but this was for each individual
per CPU buffer where this would get called many times on a machine with
many CPUs before the trace file could be read. The commit 72c9ddfd4c5bf
("ring-buffer: Make non-consuming read less expensive with lots of cpus.")
separated ring_buffer_read_start into ring_buffer_read_prepare(),
ring_buffer_read_sync() and then ring_buffer_read_start() to allow each of
the per CPU buffers to be prepared, call the read_buffer_read_sync() once,
and then the ring_buffer_read_start() for each of the CPUs which made
things much faster.

The commit 1039221cc278 ("ring-buffer: Do not disable recording when there
is an iterator") removed the requirement of disabling the recording of the
ring buffer in order to iterate it, but it did not remove the
synchronization that was happening that was required to wait for all the
buffers to have no more writers. It's now OK for the buffers to have
writers and no synchronization is needed.

Remove the synchronization and put back the interface for the ring buffer
iterator back before commit 72c9ddfd4c5bf was applied.

Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250630180440.3eabb514@batman.local.home
Reported-by: David Howells <dhowells@redhat.com>
Fixes: 1039221cc278 ("ring-buffer: Do not disable recording when there is an iterator")
Tested-by: David Howells <dhowells@redhat.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

Assisted-by: Kiro:claude-opus-4.8
[doebel@amazon.de: move patch section using guard() macro into a
separate block to address declaration after statement warning.]
Signed-off-by: Bjoern Doebel <doebel@amazon.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
KVM: x86/mmu: Ensure hugepage is in by slot before checking max mapping level 2026-07-04T11:39:37+00:00 Sean Christopherson seanjc@google.com 2026-06-26T17:46:19+00:00 7b52008023b7facf40fba3ebe92449bda8ea53b9 commit ef057cbf825e03b63f6edf5980f96abf3c53089d upstream. When recovering hugepages in the shadow MMU, verify that the base gfn of the shadow page is actually contained within the target memslot, *before* querying the max mapping level given the shadow page's gfn. Failure to pre-check the validity of the gfn can lead to an out-of-bounds access to the slot's lpage_info (which typically manifests as a host #PF because the lpage_info is vmalloc'd) if the guest creates a hugepage mapping (in its PTEs) that extends "below" the bounds of a memslot. When faulting in memory for a guest, and the size of the guest mapping is greater than KVM's (current) max mapping, then KVM will create a "direct" shadow page (direct in that there are no gPTEs to shadow, and so the target gfn is a direct calculation given the base gfn of the shadow page). The hugepage recovery flow looks for such direct shadow pages, as forcing 4KiB mappings when dirty logging generates the guest > host mapping size case. When the 4KiB restriction is lifted, then KVM can replace the shadow page with a hugepage. But if KVM originally used a smaller mapping than the guest because the range of memory covered by the guest hugepage exceeds the bounds of a memslot, then KVM will link a direct shadow page with a gfn that is outside the bounds of the memslot being used to fault in memory. The rmap entry added for the leaf mapping is correct and within bounds, but the gfn of the leaf SPTE's parent shadow page will be out of bounds. BUG: unable to handle page fault for address: ffffc90000806ffc #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 100000067 P4D 100000067 PUD 1002a7067 PMD 10612f067 PTE 0 Oops: Oops: 0000 [#1] SMP CPU: 13 UID: 1000 PID: 757 Comm: mmu_stress_test Not tainted 7.1.0-rc1-48ce1e26eace-x86_pir_to_irr_comments-vm #341 PREEMPT Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:kvm_mmu_max_mapping_level+0x79/0x2b0 [kvm] Call Trace: <TASK> kvm_mmu_recover_huge_pages+0x21b/0x320 [kvm] kvm_set_memslot+0x1ee/0x590 [kvm] kvm_set_memory_region.part.0+0x3a1/0x4d0 [kvm] kvm_vm_ioctl+0x9bf/0x15d0 [kvm] __x64_sys_ioctl+0x8a/0xd0 do_syscall_64+0xb7/0xbb0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 RIP: 0033:0x7f21c0f1a9bf </TASK> Don't bother pre-checking the bounds of the potential hugepage, i.e. don't check that e.g. sp->gfn + KVM_PAGES_PER_HPAGE(sp->role.level + 1) is also within the memslot, as the checks performed by kvm_mmu_max_mapping_level() are a superset of the basic bounds checks. I.e. pre-checking the full range would be a dubious micro-optimization. Fixes: 9eba50f8d7fc ("KVM: x86/mmu: Consult max mapping level when zapping collapsible SPTEs") Cc: stable@vger.kernel.org Cc: David Matlack <dmatlack@google.com> Cc: James Houghton <jthoughton@google.com> Cc: Alexander Bulekov <bkov@amazon.com> Cc: Fred Griffoul <fgriffo@amazon.co.uk> Cc: Alexander Graf <graf@amazon.de> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Filippo Sironi <sironi@amazon.de> Cc: Ivan Orlov <iorlov@amazon.co.uk> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
commit ef057cbf825e03b63f6edf5980f96abf3c53089d upstream.

When recovering hugepages in the shadow MMU, verify that the base gfn of
the shadow page is actually contained within the target memslot, *before*
querying the max mapping level given the shadow page's gfn.  Failure to
pre-check the validity of the gfn can lead to an out-of-bounds access to
the slot's lpage_info (which typically manifests as a host #PF because the
lpage_info is vmalloc'd) if the guest creates a hugepage mapping (in its
PTEs) that extends "below" the bounds of a memslot.

When faulting in memory for a guest, and the size of the guest mapping is
greater than KVM's (current) max mapping, then KVM will create a "direct"
shadow page (direct in that there are no gPTEs to shadow, and so the target
gfn is a direct calculation given the base gfn of the shadow page).  The
hugepage recovery flow looks for such direct shadow pages, as forcing 4KiB
mappings when dirty logging generates the guest > host mapping size case.
When the 4KiB restriction is lifted, then KVM can replace the shadow page
with a hugepage.

But if KVM originally used a smaller mapping than the guest because the
range of memory covered by the guest hugepage exceeds the bounds of a
memslot, then KVM will link a direct shadow page with a gfn that is outside
the bounds of the memslot being used to fault in memory.  The rmap entry
added for the leaf mapping is correct and within bounds, but the gfn of the
leaf SPTE's parent shadow page will be out of bounds.

  BUG: unable to handle page fault for address: ffffc90000806ffc
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD 100000067 P4D 100000067 PUD 1002a7067 PMD 10612f067 PTE 0
  Oops: Oops: 0000 [#1] SMP
  CPU: 13 UID: 1000 PID: 757 Comm: mmu_stress_test Not tainted 7.1.0-rc1-48ce1e26eace-x86_pir_to_irr_comments-vm #341 PREEMPT
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
  RIP: 0010:kvm_mmu_max_mapping_level+0x79/0x2b0 [kvm]
  Call Trace:
   <TASK>
   kvm_mmu_recover_huge_pages+0x21b/0x320 [kvm]
   kvm_set_memslot+0x1ee/0x590 [kvm]
   kvm_set_memory_region.part.0+0x3a1/0x4d0 [kvm]
   kvm_vm_ioctl+0x9bf/0x15d0 [kvm]
   __x64_sys_ioctl+0x8a/0xd0
   do_syscall_64+0xb7/0xbb0
   entry_SYSCALL_64_after_hwframe+0x4b/0x53
  RIP: 0033:0x7f21c0f1a9bf
   </TASK>

Don't bother pre-checking the bounds of the potential hugepage, i.e. don't
check that e.g. sp->gfn + KVM_PAGES_PER_HPAGE(sp->role.level + 1) is also
within the memslot, as the checks performed by kvm_mmu_max_mapping_level()
are a superset of the basic bounds checks.  I.e. pre-checking the full
range would be a dubious micro-optimization.

Fixes: 9eba50f8d7fc ("KVM: x86/mmu: Consult max mapping level when zapping collapsible SPTEs")
Cc: stable@vger.kernel.org
Cc: David Matlack <dmatlack@google.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Alexander Bulekov <bkov@amazon.com>
Cc: Fred Griffoul <fgriffo@amazon.co.uk>
Cc: Alexander Graf <graf@amazon.de>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Filippo Sironi <sironi@amazon.de>
Cc: Ivan Orlov <iorlov@amazon.co.uk>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
use less confusing names for iov_iter direction initializers 2026-06-19T11:33:46+00:00 Al Viro viro@zeniv.linux.org.uk 2026-05-30T11:40:43+00:00 31882893cafa120d76059cc080eac3bec24495df [ Upstream commit de4eda9de2d957ef2d6a8365a01e26a435e958cb ] READ/WRITE proved to be actively confusing - the meanings are "data destination, as used with read(2)" and "data source, as used with write(2)", but people keep interpreting those as "we read data from it" and "we write data to it", i.e. exactly the wrong way. Call them ITER_DEST and ITER_SOURCE - at least that is harder to misinterpret... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Stable-dep-of: a4f0b001782b ("vsock/virtio: reset connection on receiving queue overflow") Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit de4eda9de2d957ef2d6a8365a01e26a435e958cb ]

READ/WRITE proved to be actively confusing - the meanings are
"data destination, as used with read(2)" and "data source, as
used with write(2)", but people keep interpreting those as
"we read data from it" and "we write data to it", i.e. exactly
the wrong way.

Call them ITER_DEST and ITER_SOURCE - at least that is harder
to misinterpret...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Stable-dep-of: a4f0b001782b ("vsock/virtio: reset connection on receiving queue overflow")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
printk: add print_hex_dump_devel() 2026-06-19T11:33:42+00:00 Thorsten Blum thorsten.blum@linux.dev 2026-05-10T15:10:09+00:00 a59ac34ee8eb4e5d17afe01363fe8bf4f8c2de1d [ Upstream commit d134feeb5df33fbf77f482f52a366a44642dba09 ] Add print_hex_dump_devel() as the hex dump equivalent of pr_devel(), which emits output only when DEBUG is enabled, but keeps call sites compiled otherwise. Suggested-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev> Reviewed-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Stable-dep-of: 177730a273b1 ("crypto: caam - guard HMAC key hex dumps in hash_digest_key") Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit d134feeb5df33fbf77f482f52a366a44642dba09 ]

Add print_hex_dump_devel() as the hex dump equivalent of pr_devel(),
which emits output only when DEBUG is enabled, but keeps call sites
compiled otherwise.

Suggested-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Stable-dep-of: 177730a273b1 ("crypto: caam - guard HMAC key hex dumps in hash_digest_key")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
randomize_kstack: Maintain kstack_offset per task 2026-06-19T11:33:41+00:00 Ryan Roberts ryan.roberts@arm.com 2026-05-05T09:49:40+00:00 7e1b6b281aa8c084351509b1678286bf87aaf3ef [ Upstream commit 37beb42560165869838e7d91724f3e629db64129 ] kstack_offset was previously maintained per-cpu, but this caused a couple of issues. So let's instead make it per-task. Issue 1: add_random_kstack_offset() and choose_random_kstack_offset() expected and required to be called with interrupts and preemption disabled so that it could manipulate per-cpu state. But arm64, loongarch and risc-v are calling them with interrupts and preemption enabled. I don't _think_ this causes any functional issues, but it's certainly unexpected and could lead to manipulating the wrong cpu's state, which could cause a minor performance degradation due to bouncing the cache lines. By maintaining the state per-task those functions can safely be called in preemptible context. Issue 2: add_random_kstack_offset() is called before executing the syscall and expands the stack using a previously chosen random offset. choose_random_kstack_offset() is called after executing the syscall and chooses and stores a new random offset for the next syscall. With per-cpu storage for this offset, an attacker could force cpu migration during the execution of the syscall and prevent the offset from being updated for the original cpu such that it is predictable for the next syscall on that cpu. By maintaining the state per-task, this problem goes away because the per-task random offset is updated after the syscall regardless of which cpu it is executing on. Fixes: 39218ff4c625 ("stack: Optionally randomize kernel stack offset each syscall") Closes: https://lore.kernel.org/all/dd8c37bc-795f-4c7a-9086-69e584d8ab24@arm.com/ Cc: stable@vger.kernel.org Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Link: https://patch.msgid.link/20260303150840.3789438-2-ryan.roberts@arm.com Signed-off-by: Kees Cook <kees@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 37beb42560165869838e7d91724f3e629db64129 ]

kstack_offset was previously maintained per-cpu, but this caused a
couple of issues. So let's instead make it per-task.

Issue 1: add_random_kstack_offset() and choose_random_kstack_offset()
expected and required to be called with interrupts and preemption
disabled so that it could manipulate per-cpu state. But arm64, loongarch
and risc-v are calling them with interrupts and preemption enabled. I
don't _think_ this causes any functional issues, but it's certainly
unexpected and could lead to manipulating the wrong cpu's state, which
could cause a minor performance degradation due to bouncing the cache
lines. By maintaining the state per-task those functions can safely be
called in preemptible context.

Issue 2: add_random_kstack_offset() is called before executing the
syscall and expands the stack using a previously chosen random offset.
choose_random_kstack_offset() is called after executing the syscall and
chooses and stores a new random offset for the next syscall. With
per-cpu storage for this offset, an attacker could force cpu migration
during the execution of the syscall and prevent the offset from being
updated for the original cpu such that it is predictable for the next
syscall on that cpu. By maintaining the state per-task, this problem
goes away because the per-task random offset is updated after the
syscall regardless of which cpu it is executing on.

Fixes: 39218ff4c625 ("stack: Optionally randomize kernel stack offset each syscall")
Closes: https://lore.kernel.org/all/dd8c37bc-795f-4c7a-9086-69e584d8ab24@arm.com/
Cc: stable@vger.kernel.org
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Link: https://patch.msgid.link/20260303150840.3789438-2-ryan.roberts@arm.com
Signed-off-by: Kees Cook <kees@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fbdev: defio: Disconnect deferred I/O from the lifetime of struct fb_info 2026-06-19T11:33:41+00:00 Thomas Zimmermann tzimmermann@suse.de 2026-05-05T09:49:37+00:00 4aab89603b637a2e441b38808c4f6fe7d1184df6 [ Upstream commit 9ded47ad003f09a94b6a710b5c47f4aa5ceb7429 ] Hold state of deferred I/O in struct fb_deferred_io_state. Allocate an instance as part of initializing deferred I/O and remove it only after the final mapping has been closed. If the fb_info and the contained deferred I/O meanwhile goes away, clear struct fb_deferred_io_state.info to invalidate the mapping. Any access will then result in a SIGBUS signal. Fixes a long-standing problem, where a device hot-unplug happens while user space still has an active mapping of the graphics memory. The hot- unplug frees the instance of struct fb_info. Accessing the memory will operate on undefined state. Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Fixes: 60b59beafba8 ("fbdev: mm: Deferred IO support") Cc: Helge Deller <deller@gmx.de> Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: stable@vger.kernel.org # v2.6.22+ Signed-off-by: Helge Deller <deller@gmx.de> [ replaced `kzalloc_obj()` with `kzalloc(sizeof(*fbdefio_state), GFP_KERNEL)` ] Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 9ded47ad003f09a94b6a710b5c47f4aa5ceb7429 ]

Hold state of deferred I/O in struct fb_deferred_io_state. Allocate an
instance as part of initializing deferred I/O and remove it only after
the final mapping has been closed. If the fb_info and the contained
deferred I/O meanwhile goes away, clear struct fb_deferred_io_state.info
to invalidate the mapping. Any access will then result in a SIGBUS
signal.

Fixes a long-standing problem, where a device hot-unplug happens while
user space still has an active mapping of the graphics memory. The hot-
unplug frees the instance of struct fb_info. Accessing the memory will
operate on undefined state.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: 60b59beafba8 ("fbdev: mm: Deferred IO support")
Cc: Helge Deller <deller@gmx.de>
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: stable@vger.kernel.org # v2.6.22+
Signed-off-by: Helge Deller <deller@gmx.de>
[ replaced `kzalloc_obj()` with `kzalloc(sizeof(*fbdefio_state), GFP_KERNEL)` ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Disable -Wattribute-alias for clang-23 and newer 2026-06-19T11:33:32+00:00 Nathan Chancellor nathan@kernel.org 2026-05-15T19:34:14+00:00 44860077bef7942b83cad7807806a28126115fa3 commit 175db11786bde9061db526bf1ac5107d915f5163 upstream. Clang recently added support for -Wattribute-alias [1], which results in the same warnings that necessitated commit bee20031772a ("disable -Wattribute-alias warning for SYSCALL_DEFINEx()") for GCC. kernel/time/itimer.c:325:1: error: alias and aliasee have different types 'long (unsigned int)' and 'long (typeof (__builtin_choose_expr((__builtin_types_compatible_p(typeof ((unsigned int)0), typeof (0LL)) || __builtin_types_compatible_p(typeof ((unsigned int)0), typeof (0ULL))), 0LL, 0L)))' (aka 'long (long)') [-Werror,-Wattribute-alias] 325 | SYSCALL_DEFINE1(alarm, unsigned int, seconds) | ^ include/linux/syscalls.h:225:36: note: expanded from macro 'SYSCALL_DEFINE1' 225 | #define SYSCALL_DEFINE1(name, ...) SYSCALL_DEFINEx(1, _##name, __VA_ARGS__) | ^ include/linux/syscalls.h:236:2: note: expanded from macro 'SYSCALL_DEFINEx' 236 | __SYSCALL_DEFINEx(x, sname, __VA_ARGS__) | ^ include/linux/syscalls.h:251:18: note: expanded from macro '__SYSCALL_DEFINEx' 251 | __attribute__((alias(__stringify(__se_sys##name)))); \ | ^ kernel/time/itimer.c:325:1: note: aliasee is declared here include/linux/syscalls.h:225:36: note: expanded from macro 'SYSCALL_DEFINE1' 225 | #define SYSCALL_DEFINE1(name, ...) SYSCALL_DEFINEx(1, _##name, __VA_ARGS__) | ^ include/linux/syscalls.h:236:2: note: expanded from macro 'SYSCALL_DEFINEx' 236 | __SYSCALL_DEFINEx(x, sname, __VA_ARGS__) | ^ include/linux/syscalls.h:255:18: note: expanded from macro '__SYSCALL_DEFINEx' 255 | asmlinkage long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \ | ^ <scratch space>:16:1: note: expanded from here 16 | __se_sys_alarm | ^ Disable the warnings in the same way for clang-23 and newer. Disable the warning about unknown warning options to avoid breaking the build for versions of clang-23 that do not have -Wattribute-alias, such as ones deployed by vendors like Android or CI systems or when bisecting LLVM between llvmorg-23-init and release/23.x. Cc: stable@vger.kernel.org Closes: https://github.com/ClangBuiltLinux/linux/issues/2163 Link: https://github.com/llvm/llvm-project/commit/40da6920a0d71d49dfa2392b09153600b0759f5e [1] Link: https://patch.msgid.link/20260515-syscall-disable-attribute-alias-for-clang-v1-1-9a9d95d41df6@kernel.org [nathan: Drop arch/riscv hunk in older trees and address conflicts] Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
commit 175db11786bde9061db526bf1ac5107d915f5163 upstream.

Clang recently added support for -Wattribute-alias [1], which results in
the same warnings that necessitated commit bee20031772a ("disable
-Wattribute-alias warning for SYSCALL_DEFINEx()") for GCC.

  kernel/time/itimer.c:325:1: error: alias and aliasee have different types 'long (unsigned int)' and 'long (typeof (__builtin_choose_expr((__builtin_types_compatible_p(typeof ((unsigned int)0), typeof (0LL)) || __builtin_types_compatible_p(typeof ((unsigned int)0), typeof (0ULL))), 0LL, 0L)))' (aka 'long (long)') [-Werror,-Wattribute-alias]
    325 | SYSCALL_DEFINE1(alarm, unsigned int, seconds)
        | ^
  include/linux/syscalls.h:225:36: note: expanded from macro 'SYSCALL_DEFINE1'
    225 | #define SYSCALL_DEFINE1(name, ...) SYSCALL_DEFINEx(1, _##name, __VA_ARGS__)
        |                                    ^
  include/linux/syscalls.h:236:2: note: expanded from macro 'SYSCALL_DEFINEx'
    236 |         __SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
        |         ^
  include/linux/syscalls.h:251:18: note: expanded from macro '__SYSCALL_DEFINEx'
    251 |                 __attribute__((alias(__stringify(__se_sys##name))));    \
        |                                ^
  kernel/time/itimer.c:325:1: note: aliasee is declared here
  include/linux/syscalls.h:225:36: note: expanded from macro 'SYSCALL_DEFINE1'
    225 | #define SYSCALL_DEFINE1(name, ...) SYSCALL_DEFINEx(1, _##name, __VA_ARGS__)
        |                                    ^
  include/linux/syscalls.h:236:2: note: expanded from macro 'SYSCALL_DEFINEx'
    236 |         __SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
        |         ^
  include/linux/syscalls.h:255:18: note: expanded from macro '__SYSCALL_DEFINEx'
    255 |         asmlinkage long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__))  \
        |                         ^
  <scratch space>:16:1: note: expanded from here
     16 | __se_sys_alarm
        | ^

Disable the warnings in the same way for clang-23 and newer. Disable the
warning about unknown warning options to avoid breaking the build for
versions of clang-23 that do not have -Wattribute-alias, such as ones
deployed by vendors like Android or CI systems or when bisecting LLVM
between llvmorg-23-init and release/23.x.

Cc: stable@vger.kernel.org
Closes: https://github.com/ClangBuiltLinux/linux/issues/2163
Link: https://github.com/llvm/llvm-project/commit/40da6920a0d71d49dfa2392b09153600b0759f5e [1]
Link: https://patch.msgid.link/20260515-syscall-disable-attribute-alias-for-clang-v1-1-9a9d95d41df6@kernel.org
[nathan: Drop arch/riscv hunk in older trees and address conflicts]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
compiler-clang.h: Add __diag infrastructure for clang 2026-06-19T11:33:32+00:00 Nathan Chancellor nathan@kernel.org 2022-03-04T22:46:42+00:00 80e416880b981fb826b6d71175a7eebbf7b82799 commit f014a00bbeb09cea16017b82448d32a468a6b96f upstream. Add __diag macros similar to those in compiler-gcc.h, so that warnings that need to be adjusted for specific cases but not globally can be ignored when building with clang. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20220304224645.3677453-6-memxor@gmail.com [ Kartikeya: wrote commit message ] Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
commit f014a00bbeb09cea16017b82448d32a468a6b96f upstream.

Add __diag macros similar to those in compiler-gcc.h, so that warnings
that need to be adjusted for specific cases but not globally can be
ignored when building with clang.

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220304224645.3677453-6-memxor@gmail.com

[ Kartikeya: wrote commit message ]

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
HID: pass the buffer size to hid_report_raw_event 2026-06-19T11:33:31+00:00 Benjamin Tissoires bentiss@kernel.org 2026-06-04T09:26:51+00:00 a4d6cb7cf45bddc76c78ed5fd683328af9e2018f [ Upstream commit 2c85c61d1332e1e16f020d76951baf167dcb6f7a ] commit 0a3fe972a7cb ("HID: core: Mitigate potential OOB by removing bogus memset()") enforced the provided data to be at least the size of the declared buffer in the report descriptor to prevent a buffer overflow. However, we can try to be smarter by providing both the buffer size and the data size, meaning that hid_report_raw_event() can make better decision whether we should plaining reject the buffer (buffer overflow attempt) or if we can safely memset it to 0 and pass it to the rest of the stack. Fixes: 0a3fe972a7cb ("HID: core: Mitigate potential OOB by removing bogus memset()") Cc: stable@vger.kernel.org Signed-off-by: Benjamin Tissoires <bentiss@kernel.org> Acked-by: Johan Hovold <johan@kernel.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Jiri Kosina <jkosina@suse.com> Stable-dep-of: 206342541fc8 ("HID: core: introduce hid_safe_input_report()") [Lee: Backported to linux-6.12.y and beyond] Signed-off-by: Lee Jones <lee@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 2c85c61d1332e1e16f020d76951baf167dcb6f7a ]

commit 0a3fe972a7cb ("HID: core: Mitigate potential OOB by removing
bogus memset()") enforced the provided data to be at least the size of
the declared buffer in the report descriptor to prevent a buffer
overflow. However, we can try to be smarter by providing both the buffer
size and the data size, meaning that hid_report_raw_event() can make
better decision whether we should plaining reject the buffer (buffer
overflow attempt) or if we can safely memset it to 0 and pass it to the
rest of the stack.

Fixes: 0a3fe972a7cb ("HID: core: Mitigate potential OOB by removing bogus memset()")
Cc: stable@vger.kernel.org
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
Acked-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
Stable-dep-of: 206342541fc8 ("HID: core: introduce hid_safe_input_report()")
[Lee: Backported to linux-6.12.y and beyond]
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
HID: core: Add printk_ratelimited variants to hid_warn() etc 2026-06-19T11:33:31+00:00 Vicki Pfau vi@endrift.com 2026-06-04T09:26:50+00:00 6f59d1468a9abdda50a6c8d058c38d63c9240653 [ Upstream commit 1d64624243af8329b4b219d8c39e28ea448f9929 ] hid_warn_ratelimited() is needed. Add the others as part of the block. Signed-off-by: Vicki Pfau <vi@endrift.com> Signed-off-by: Jiri Kosina <jkosina@suse.com> Signed-off-by: Lee Jones <lee@kernel.org> Signed-off-by: Lee Jones <lee@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 1d64624243af8329b4b219d8c39e28ea448f9929 ]

hid_warn_ratelimited() is needed. Add the others as part of the block.

Signed-off-by: Vicki Pfau <vi@endrift.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>