commit cb22f247f371bd206a88cf0e0c05d80b8b62fb26 upstream.
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+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f6334f4ae9a4e962ba74b026e1d965dfdf8cbef8 upstream. 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+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 52ce9406a9625c4498c4eaa51e7a7ed9dcb9db16 upstream. 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+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4eab1c27ce1f0e89ab67b01bf1e4e4c75215708a upstream. 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+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull Kbuild updates from Masahiro Yamada:
- Add support for the EXPORT_SYMBOL_GPL_FOR_MODULES() macro, which
exports a symbol only to specified modules
- Improve ABI handling in gendwarfksyms
- Forcibly link lib-y objects to vmlinux even if CONFIG_MODULES=n
- Add checkers for redundant or missing <linux/export.h> inclusion
- Deprecate the extra-y syntax
- Fix a genksyms bug when including enum constants from *.symref files
* tag 'kbuild-v6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (28 commits)
genksyms: Fix enum consts from a reference affecting new values
arch: use always-$(KBUILD_BUILTIN) for vmlinux.lds
kbuild: set y instead of 1 to KBUILD_{BUILTIN,MODULES}
efi/libstub: use 'targets' instead of extra-y in Makefile
module: make __mod_device_table__* symbols static
scripts/misc-check: check unnecessary #include <linux/export.h> when W=1
scripts/misc-check: check missing #include <linux/export.h> when W=1
scripts/misc-check: add double-quotes to satisfy shellcheck
kbuild: move W=1 check for scripts/misc-check to top-level Makefile
scripts/tags.sh: allow to use alternative ctags implementation
kconfig: introduce menu type enum
docs: symbol-namespaces: fix reST warning with literal block
kbuild: link lib-y objects to vmlinux forcibly even when CONFIG_MODULES=n
tinyconfig: enable CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
docs/core-api/symbol-namespaces: drop table of contents and section numbering
modpost: check forbidden MODULE_IMPORT_NS("module:") at compile time
kbuild: move kbuild syntax processing to scripts/Makefile.build
Makefile: remove dependency on archscripts for header installation
Documentation/kbuild: Add new gendwarfksyms kABI rules
Documentation/kbuild: Drop section numbers
...
The extra-y syntax is deprecated. Instead, use always-$(KBUILD_BUILTIN), which behaves equivalently. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Johannes Berg <johannes@sipsolutions.net> Reviewed-by: Nicolas Schier <n.schier@avm.de>
Change back printk format to 0x%08lx instead of %#08lx, since the latter
does not seem to reliably format the value to 8 hex chars.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # v5.18+
Fixes: e5e9e7f222e5b ("parisc/unaligned: Enhance user-space visible output")
Pull parisc updates from Helge Deller: - drop parisc specific memcpy_fromio() function - clean up coding style and fix compile warnings * tag 'parisc-for-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: parisc: led: Use scnprintf() to avoid string truncation warning Input: gscps2 - Describe missing function parameters parisc: perf: use named initializers for struct miscdevice parisc: PDT: Fix missing prototype warning parisc: Remove memcpy_fromio parisc: Fix formatting errors in io.c
Pull VDSO infrastructure updates from Thomas Gleixner: - Consolidate the VDSO storage The VDSO data storage and data layout has been largely architecture specific for historical reasons. That increases the maintenance effort and causes inconsistencies over and over. There is no real technical reason for architecture specific layouts and implementations. The architecture specific details can easily be integrated into a generic layout, which also reduces the amount of duplicated code for managing the mappings. Convert all architectures over to a unified layout and common mapping infrastructure. This splits the VDSO data layout into subsystem specific blocks, timekeeping, random and architecture parts, which provides a better structure and allows to improve and update the functionalities without conflict and interaction. - Rework the timekeeping data storage The current implementation is designed for exposing system timekeeping accessors, which was good enough at the time when it was designed. PTP and Time Sensitive Networking (TSN) change that as there are requirements to expose independent PTP clocks, which are not related to system timekeeping. Replace the monolithic data storage by a structured layout, which allows to add support for independent PTP clocks on top while reusing both the data structures and the time accessor implementations. * tag 'timers-vdso-2025-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (55 commits) sparc/vdso: Always reject undefined references during linking x86/vdso: Always reject undefined references during linking vdso: Rework struct vdso_time_data and introduce struct vdso_clock vdso: Move architecture related data before basetime data powerpc/vdso: Prepare introduction of struct vdso_clock arm64/vdso: Prepare introduction of struct vdso_clock x86/vdso: Prepare introduction of struct vdso_clock time/namespace: Prepare introduction of struct vdso_clock vdso/namespace: Rename timens_setup_vdso_data() to reflect new vdso_clock struct vdso/vsyscall: Prepare introduction of struct vdso_clock vdso/gettimeofday: Prepare helper functions for introduction of struct vdso_clock vdso/gettimeofday: Prepare do_coarse_timens() for introduction of struct vdso_clock vdso/gettimeofday: Prepare do_coarse() for introduction of struct vdso_clock vdso/gettimeofday: Prepare do_hres_timens() for introduction of struct vdso_clock vdso/gettimeofday: Prepare do_hres() for introduction of struct vdso_clock vdso/gettimeofday: Prepare introduction of struct vdso_clock vdso/helpers: Prepare introduction of struct vdso_clock vdso/datapage: Define vdso_clock to prepare for multiple PTP clocks vdso: Make vdso_time_data cacheline aligned arm64: Make asm/cache.h compatible with vDSO ...
Though struct miscdevice has hardly changed over the years, this is good practice and also makes the core more readable. Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@igalia.com> Signed-off-by: Helge Deller <deller@gmx.de>