commit fd9f30d1038ee1624baa17a6ff11effe5f7617cb upstream. Guenter Roeck reported this kernel crash on his emulated B160L machine: Starting network: udhcpc: started, v1.36.1 Backtrace: [<104320d4>] unwind_once+0x1c/0x5c [<10434a00>] walk_stackframe.isra.0+0x74/0xb8 [<10434a6c>] arch_stack_walk+0x28/0x38 [<104e5efc>] stack_trace_save+0x48/0x5c [<105d1bdc>] set_track_prepare+0x44/0x6c [<105d9c80>] ___slab_alloc+0xfc4/0x1024 [<105d9d38>] __slab_alloc.isra.0+0x58/0x90 [<105dc80c>] kmem_cache_alloc_noprof+0x2ac/0x4a0 [<105b8e54>] __anon_vma_prepare+0x60/0x280 [<105a823c>] __vmf_anon_prepare+0x68/0x94 [<105a8b34>] do_wp_page+0x8cc/0xf10 [<105aad88>] handle_mm_fault+0x6c0/0xf08 [<10425568>] do_page_fault+0x110/0x440 [<10427938>] handle_interruption+0x184/0x748 [<11178398>] schedule+0x4c/0x190 BUG: spinlock recursion on CPU#0, ifconfig/2420 lock: terminate_lock.2+0x0/0x1c, .magic: dead4ead, .owner: ifconfig/2420, .owner_cpu: 0 While creating the stack trace, the unwinder uses the stack pointer to guess the previous frame to read the previous stack pointer from memory. The crash happens, because the unwinder tries to read from unaligned memory and as such triggers the unalignment trap handler which then leads to the spinlock recursion and finally to a deadlock. Fix it by checking the alignment before accessing the memory. Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Helge Deller <deller@gmx.de> Tested-by: Guenter Roeck <linux@roeck-us.net> Cc: stable@vger.kernel.org # v6.12+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 35561bab768977c9e05f1f1a9bc00134c85f3e28 ] The include/generated/asm-offsets.h is generated in Kbuild during compiling from arch/SRCARCH/kernel/asm-offsets.c. When we want to generate another similar offset header file, circular dependency can happen. For example, we want to generate a offset file include/generated/test.h, which is included in include/sched/sched.h. If we generate asm-offsets.h first, it will fail, as include/sched/sched.h is included in asm-offsets.c and include/generated/test.h doesn't exist; If we generate test.h first, it can't success neither, as include/generated/asm-offsets.h is included by it. In x86_64, the macro COMPILE_OFFSETS is used to avoid such circular dependency. We can generate asm-offsets.h first, and if the COMPILE_OFFSETS is defined, we don't include the "generated/test.h". And we define the macro COMPILE_OFFSETS for all the asm-offsets.c for this purpose. Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit bbc46b23af5bb934cd1cf066ef4342cee457a24e ]
With the introduction of clone3 in commit 7f192e3cd316 ("fork: add
clone3") the effective bit width of clone_flags on all architectures was
increased from 32-bit to 64-bit, with a new type of u64 for the flags.
However, for most consumers of clone_flags the interface was not
changed from the previous type of unsigned long.
While this works fine as long as none of the new 64-bit flag bits
(CLONE_CLEAR_SIGHAND and CLONE_INTO_CGROUP) are evaluated, this is still
undesirable in terms of the principle of least surprise.
Thus, this commit fixes all relevant interfaces of the copy_thread
function that is called from copy_process to consistently pass
clone_flags as u64, so that no truncation to 32-bit integers occurs on
32-bit architectures.
Signed-off-by: Simon Schuster <schuster.simon@siemens-energy.com>
Link: https://lore.kernel.org/20250901-nios2-implement-clone3-v2-3-53fcf5577d57@siemens-energy.com
Fixes: c5febea0956fd387 ("fork: Pass struct kernel_clone_args into copy_thread")
Acked-by: Guo Ren (Alibaba Damo Academy) <guoren@kernel.org>
Acked-by: Andreas Larsson <andreas@gaisler.com> # sparc
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> # m68k
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Pull parisc updates from Helge Deller: - The parisc kernel wrongly allows reading from read-protected userspace memory without faulting, e.g. when userspace uses mprotect() to read-protect a memory area and then uses a pointer to this memory in a write(2, addr, 1) syscall. To fix this issue, Dave Anglin developed a set of patches which use the proberi assembler instruction to additionally check read access permissions at runtime. - Randy Dunlap contributed two patches to fix a minor typo and to explain why a 32-bit compiler is needed although a 64-bit kernel is built * tag 'parisc-for-6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: parisc: Revise __get_user() to probe user read access parisc: Revise gateway LWS calls to probe user read access parisc: Drop WARN_ON_ONCE() from flush_cache_vmap parisc: Try to fixup kernel exception in bad_area_nosemaphore path of do_page_fault() parisc: Define and use set_pte_at() parisc: Rename pte_needs_flush() to pte_needs_cache_flush() in cache.c parisc: Check region is readable by user in raw_copy_from_user() parisc: Update comments in make_insert_tlb parisc: Makefile: explain that 64BIT requires both 32-bit and 64-bit compilers parisc: Makefile: fix a typo in palo.conf
Pull execve updates from Kees Cook: - Introduce regular REGSET note macros arch-wide (Dave Martin) - Remove arbitrary 4K limitation of program header size (Yin Fengwei) - Reorder function qualifiers for copy_clone_args_from_user() (Dishank Jogi) * tag 'execve-v6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (25 commits) fork: reorder function qualifiers for copy_clone_args_from_user binfmt_elf: remove the 4k limitation of program header size binfmt_elf: Warn on missing or suspicious regset note names xtensa: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names um: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names x86/ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names sparc: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names sh: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names s390/ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names riscv: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names powerpc/ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names parisc: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names openrisc: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names nios2: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names MIPS: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names m68k: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names LoongArch: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names hexagon: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names csky: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names arm64: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names ...
We use load and stbys,e instructions to trigger memory reference interruptions without writing to memory. Because of the way read access support is implemented, read access interruptions are only triggered at privilege levels 2 and 3. The kernel and gateway page execute at privilege level 0, so this code never triggers a read access interruption. Thus, it is currently possible for user code to execute a LWS compare and swap operation at an address that is read protected at privilege level 3 (PRIV_USER). Fix this by probing read access rights at privilege level 3 and branching to lws_fault if access isn't allowed. Signed-off-by: John David Anglin <dave.anglin@bell.net> Signed-off-by: Helge Deller <deller@gmx.de> Cc: stable@vger.kernel.org # v5.12+
I have observed warning to occassionally trigger. Signed-off-by: John David Anglin <dave.anglin@bell.net> Signed-off-by: Helge Deller <deller@gmx.de> Cc: stable@vger.kernel.org # v5.12+
The local name used in cache.c conflicts the declaration in include/asm-generic/tlb.h. Signed-off-by: John David Anglin <dave.anglin@bell.net> Signed-off-by: Helge Deller <deller@gmx.de> Cc: stable@vger.kernel.org # v5.12+
The following testcase exposed a problem with our read access checks
in get_user() and raw_copy_from_user():
#include <stdint.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <sys/mman.h>
#include <sys/types.h>
int main(int argc, char **argv)
{
unsigned long page_size = sysconf(_SC_PAGESIZE);
char *p = malloc(3 * page_size);
char *p_aligned;
/* initialize memory region. If not initialized, write syscall below will correctly return EFAULT. */
if (1)
memset(p, 'X', 3 * page_size);
p_aligned = (char *) ((((uintptr_t) p) + (2*page_size - 1)) & ~(page_size - 1));
/* Drop PROT_READ protection. Kernel and userspace should fault when accessing that memory region */
mprotect(p_aligned, page_size, PROT_NONE);
/* the following write() should return EFAULT, since PROT_READ was dropped by previous mprotect() */
int ret = write(2, p_aligned, 1);
if (!ret || errno != EFAULT)
printf("\n FAILURE: write() did not returned expected EFAULT value\n");
return 0;
}
Because of the way _PAGE_READ is handled, kernel code never generates
a read access fault when it access a page as the kernel privilege level
is always less than PL1 in the PTE.
This patch reworks the comments in the make_insert_tlb macro to try
to make this clearer.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # v5.12+
Instead of having the core code guess the note name for each regset, use USER_REGSET_NOTE_TYPE() to pick the correct name from elf.h. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com> Cc: Helge Deller <deller@gmx.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Kees Cook <kees@kernel.org> Cc: Akihiko Odaki <akihiko.odaki@daynix.com> Cc: linux-parisc@vger.kernel.org Reviewed-by: Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp> Link: https://lore.kernel.org/r/20250701135616.29630-15-Dave.Martin@arm.com Signed-off-by: Kees Cook <kees@kernel.org>