kernel.git/arch/parisc/kernel, branch linux-5.13.y

parisc: fix crash with signals and alloca

2021-09-18T11:42:20Z

commit 030f653078316a9cc9ca6bd1b0234dcf858be35d upstream. I was debugging some crashes on parisc and I found out that there is a crash possibility if a function using alloca is interrupted by a signal. The reason for the crash is that the gcc alloca implementation leaves garbage in the upper 32 bits of the sp register. This normally doesn't matter (the upper bits are ignored because the PSW W-bit is clear), however the signal delivery routine in the kernel uses full 64 bits of sp and it fails with -EFAULT if the upper 32 bits are not zero. I created this program that demonstrates the problem: #include #include #include #include static __attribute__((noinline,noclone)) void aa(int *size) { void * volatile p = alloca(-*size); while (1) ; } static void handler(int sig) { write(1, "signal delivered\n", 17); _exit(0); } int main(void) { int size = -0x100; signal(SIGALRM, handler); alarm(1); aa(&size); } If you compile it with optimizations, it will crash. The "aa" function has this disassembly: 000106a0 : 106a0: 08 03 02 41 copy r3,r1 106a4: 08 1e 02 43 copy sp,r3 106a8: 6f c1 00 80 stw,ma r1,40(sp) 106ac: 37 dc 3f c1 ldo -20(sp),ret0 106b0: 0c 7c 12 90 stw ret0,8(r3) 106b4: 0f 40 10 9c ldw 0(r26),ret0 ; ret0 = 0x00000000FFFFFF00 106b8: 97 9c 00 7e subi 3f,ret0,ret0 ; ret0 = 0xFFFFFFFF0000013F 106bc: d7 80 1c 1a depwi 0,31,6,ret0 ; ret0 = 0xFFFFFFFF00000100 106c0: 0b 9e 0a 1e add,l sp,ret0,sp ; sp = 0xFFFFFFFFxxxxxxxx 106c4: e8 1f 1f f7 b,l,n 106c4 ,r0 This patch fixes the bug by truncating the "usp" variable to 32 bits. Signed-off-by: Mikulas Patocka Cc: stable@vger.kernel.org Signed-off-by: Helge Deller Signed-off-by: Greg Kroah-Hartman

Revert "parisc: Add assembly implementations for memset, strlen, strcpy, strncpy and strcat"

2021-09-03T08:23:07Z

commit f6a3308d6feb351d9854eb8b3f6289a1ac163125 upstream. This reverts commit 83af58f8068ea3f7b3c537c37a30887bfa585069. It turns out that at least the assembly implementation for strncpy() was buggy. Revert the whole commit and return back to the default coding. Signed-off-by: Helge Deller Cc: # v5.4+ Cc: Rasmus Villemoes Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

sched/core: Initialize the idle task with preemption disabled

2021-07-14T15:06:21Z

[ Upstream commit f1a0a376ca0c4ef1fc3d24e3e502acbb5b795674 ] As pointed out by commit de9b8f5dcbd9 ("sched: Fix crash trying to dequeue/enqueue the idle thread") init_idle() can and will be invoked more than once on the same idle task. At boot time, it is invoked for the boot CPU thread by sched_init(). Then smp_init() creates the threads for all the secondary CPUs and invokes init_idle() on them. As the hotplug machinery brings the secondaries to life, it will issue calls to idle_thread_get(), which itself invokes init_idle() yet again. In this case it's invoked twice more per secondary: at _cpu_up(), and at bringup_cpu(). Given smp_init() already initializes the idle tasks for all *possible* CPUs, no further initialization should be required. Now, removing init_idle() from idle_thread_get() exposes some interesting expectations with regards to the idle task's preempt_count: the secondary startup always issues a preempt_disable(), requiring some reset of the preempt count to 0 between hot-unplug and hotplug, which is currently served by idle_thread_get() -> idle_init(). Given the idle task is supposed to have preemption disabled once and never see it re-enabled, it seems that what we actually want is to initialize its preempt_count to PREEMPT_DISABLED and leave it there. Do that, and remove init_idle() from idle_thread_get(). Secondary startups were patched via coccinelle: @begone@ @@ -preempt_disable(); ... cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); Signed-off-by: Valentin Schneider Signed-off-by: Ingo Molnar Acked-by: Peter Zijlstra Link: https://lore.kernel.org/r/20210512094636.2958515-1-valentin.schneider@arm.com Signed-off-by: Sasha Levin

quota: Disable quotactl_path syscall

2021-05-17T12:39:56Z

In commit fa8b90070a80 ("quota: wire up quotactl_path") we have wired up new quotactl_path syscall. However some people in LWN discussion have objected that the path based syscall is missing dirfd and flags argument which is mostly standard for contemporary path based syscalls. Indeed they have a point and after a discussion with Christian Brauner and Sascha Hauer I've decided to disable the syscall for now and update its API. Since there is no userspace currently using that syscall and it hasn't been released in any major release, we should be fine. CC: Christian Brauner CC: Sascha Hauer Link: https://lore.kernel.org/lkml/20210512153621.n5u43jsytbik4yze@wittgenstein Signed-off-by: Jan Kara

Merge tag 'for-5.13/parisc' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux

2021-05-03T20:47:17Z

Pull parisc architecture updates from Helge Deller: - switch to generic syscall header scripts - minor typo fix in setup.c * tag 'for-5.13/parisc' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: parisc: Fix typo in setup.c parisc: syscalls: switch to generic syscallhdr.sh parisc: syscalls: switch to generic syscalltbl.sh

parisc: Fix typo in setup.c

2021-05-03T13:08:59Z

Signed-off-by: Helge Deller

Merge tag 'landlock_v34' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

2021-05-02T01:50:44Z

Pull Landlock LSM from James Morris: "Add Landlock, a new LSM from Mickaël Salaün. Briefly, Landlock provides for unprivileged application sandboxing. From Mickaël's cover letter: "The goal of Landlock is to enable to restrict ambient rights (e.g. global filesystem access) for a set of processes. Because Landlock is a stackable LSM [1], it makes possible to create safe security sandboxes as new security layers in addition to the existing system-wide access-controls. This kind of sandbox is expected to help mitigate the security impact of bugs or unexpected/malicious behaviors in user-space applications. Landlock empowers any process, including unprivileged ones, to securely restrict themselves. Landlock is inspired by seccomp-bpf but instead of filtering syscalls and their raw arguments, a Landlock rule can restrict the use of kernel objects like file hierarchies, according to the kernel semantic. Landlock also takes inspiration from other OS sandbox mechanisms: XNU Sandbox, FreeBSD Capsicum or OpenBSD Pledge/Unveil. In this current form, Landlock misses some access-control features. This enables to minimize this patch series and ease review. This series still addresses multiple use cases, especially with the combined use of seccomp-bpf: applications with built-in sandboxing, init systems, security sandbox tools and security-oriented APIs [2]" The cover letter and v34 posting is here: https://lore.kernel.org/linux-security-module/20210422154123.13086-1-mic@digikod.net/ See also: https://landlock.io/ This code has had extensive design discussion and review over several years" Link: https://lore.kernel.org/lkml/50db058a-7dde-441b-a7f9-f6837fe8b69f@schaufler-ca.com/ [1] Link: https://lore.kernel.org/lkml/f646e1c7-33cf-333f-070c-0a40ad0468cd@digikod.net/ [2] * tag 'landlock_v34' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: landlock: Enable user space to infer supported features landlock: Add user and kernel documentation samples/landlock: Add a sandbox manager example selftests/landlock: Add user space tests landlock: Add syscall implementations arch: Wire up Landlock syscalls fs,security: Add sb_delete hook landlock: Support filesystem access-control LSM: Infrastructure management of the superblock landlock: Add ptrace restrictions landlock: Set up the security framework and manage credentials landlock: Add ruleset and domain management landlock: Add object management

parisc: syscalls: switch to generic syscallhdr.sh

2021-04-27T07:43:56Z

Many architectures duplicate similar shell scripts. This commit converts parisc to use scripts/syscallhdr.sh. Signed-off-by: Masahiro Yamada Signed-off-by: Helge Deller

parisc: syscalls: switch to generic syscalltbl.sh

2021-04-27T07:43:56Z

Many architectures duplicate similar shell scripts. This commit converts parisc to use scripts/syscalltbl.sh. This also unifies syscall_table_64.h and syscall_table_c32.h. Signed-off-by: Masahiro Yamada Acked-by: Helge Deller Signed-off-by: Helge Deller

arch: Wire up Landlock syscalls

2021-04-22T19:22:11Z

Wire up the following system calls for all architectures: * landlock_create_ruleset(2) * landlock_add_rule(2) * landlock_restrict_self(2) Cc: Arnd Bergmann Cc: James Morris Cc: Jann Horn Cc: Kees Cook Cc: Serge E. Hallyn Signed-off-by: Mickaël Salaün Link: https://lore.kernel.org/r/20210422154123.13086-10-mic@digikod.net Signed-off-by: James Morris