Close the hole where ptrace can change a syscall out from under seccomp.
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-parisc@vger.kernel.org
Currently, if arch code wants to supply seccomp_data directly to
seccomp (which is generally much faster than having seccomp do it
using the syscall_get_xyz() API), it has to use the two-phase
seccomp hooks. Add it to the easy hooks, too.
Cc: linux-arch@vger.kernel.org
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
By adding TRACEHOOK support we now get a clean user interface to access
registers via PTRACE_GETREGS, PTRACE_SETREGS, PTRACE_GETFPREGS and
PTRACE_SETFPREGS.
The user-visible regset struct user_regs_struct and user_fp_struct are
modelled similiar to x86 and can be accessed via PTRACE_GETREGSET.
Signed-off-by: Helge Deller <deller@gmx.de>
This patch adds support for the TIF_SYSCALL_TRACEPOINT on the parisc
architecture. Basically, it calls the appropriate tracepoints on syscall
entry and exit.
Signed-off-by: Helge Deller <deller@gmx.de>
The seccomp filter support requires careful handling of task registers. This
includes reloading of the return value (%r28) and proper syscall exit if
secure_computing() returned -1.
Additionally we need to sign-extend the syscall number from signed 32bit to
signed 64bit in do_syscall_trace_enter() since the ptrace interface only allows
storing 32bit values in compat mode.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # v4.5
Mike Frysinger reported that his ptrace testcase showed strange
behaviour on parisc: It was not possible to avoid a syscall and the
return value of a syscall couldn't be changed.
To modify a syscall number, we were missing to save the new syscall
number to gr20 which is then picked up later in assembly again.
The effect that the return value couldn't be changed is a side-effect of
another bug in the assembly code. When a process is ptraced, userspace
expects each syscall to report entrance and exit of a syscall. If a
syscall number was given which doesn't exist, we jumped to the normal
syscall exit code instead of informing userspace that the (non-existant)
syscall exits. This unexpected behaviour confuses userspace and thus the
bug was misinterpreted as if we can't change the return value.
This patch fixes both problems and was tested on 64bit kernel with
32bit userspace.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: stable@vger.kernel.org # v4.0+
Tested-by: Mike Frysinger <vapier@gentoo.org>
Pull audit updates from Eric Paris:
"So this change across a whole bunch of arches really solves one basic
problem. We want to audit when seccomp is killing a process. seccomp
hooks in before the audit syscall entry code. audit_syscall_entry
took as an argument the arch of the given syscall. Since the arch is
part of what makes a syscall number meaningful it's an important part
of the record, but it isn't available when seccomp shoots the
syscall...
For most arch's we have a better way to get the arch (syscall_get_arch)
So the solution was two fold: Implement syscall_get_arch() everywhere
there is audit which didn't have it. Use syscall_get_arch() in the
seccomp audit code. Having syscall_get_arch() everywhere meant it was
a useless flag on the stack and we could get rid of it for the typical
syscall entry.
The other changes inside the audit system aren't grand, fixed some
records that had invalid spaces. Better locking around the task comm
field. Removing some dead functions and structs. Make some things
static. Really minor stuff"
* git://git.infradead.org/users/eparis/audit: (31 commits)
audit: rename audit_log_remove_rule to disambiguate for trees
audit: cull redundancy in audit_rule_change
audit: WARN if audit_rule_change called illegally
audit: put rule existence check in canonical order
next: openrisc: Fix build
audit: get comm using lock to avoid race in string printing
audit: remove open_arg() function that is never used
audit: correct AUDIT_GET_FEATURE return message type
audit: set nlmsg_len for multicast messages.
audit: use union for audit_field values since they are mutually exclusive
audit: invalid op= values for rules
audit: use atomic_t to simplify audit_serial()
kernel/audit.c: use ARRAY_SIZE instead of sizeof/sizeof[0]
audit: reduce scope of audit_log_fcaps
audit: reduce scope of audit_net_id
audit: arm64: Remove the audit arch argument to audit_syscall_entry
arm64: audit: Add audit hook in syscall_trace_enter/exit()
audit: x86: drop arch from __audit_syscall_entry() interface
sparc: implement is_32bit_task
sparc: properly conditionalize use of TIF_32BIT
...
Various GCC tests use gdb to simulate a multithreaded application. Many of
these tests have been failing on parisc linux.
GCC does this by using gdb to single-step the application, then gdb is used to
call other test specific code. Where this fails is when the application is
stepped into the delay slot of a taken branch. This sets the PSW B bit. When
the test specific code is executed, this usually clears the PSW B bit.
Currently, gdb is not allowed to set the B bit. So, the code falls through what
should be a taken branch.
The attached patch adds the PSW B bit to the set of bits that gdb is allowed to
set. In order to set the B bit, the trace system call must return using an
interrupt restore. The patch also modifies this code to use the saved IAOQ
values when they are saved by a ptrace syscall or interruption.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
Fix up the arguments to arch_ptrace() to take account of the fact that
@addr and @data are now unsigned long rather than long as of a preceding
patch in this series.
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: <linux-arch@vger.kernel.org>
Acked-by: Roland McGrath <roland@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
task->ptrace flags belong to generic code, so instead thief some
TIF_ bits to use. Somewhat risky conversion of code to test TASK_FLAGS
instead of TASK_PTRACE in assembly, but it looks alright in the end.
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
Instead of fiddling with gr[20], restructure code to return whether
or not to -ENOSYS. (Also do a bit of fiddling to let them take
pt_regs directly instead of re-computing it.)
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
This makes parisc use the standard tracehook_report_syscall_entry
and tracehook_report_syscall_exit hooks in <linux/tracehook.h>.
To do this, we need to access current->thread.regs, and to know
whether we're entering or exiting the syscall, so add this to
syscall_trace.
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
Commit 81e192d6ce ("parisc: convert to
generic compat_sys_ptrace") introduced a bug which segfaults the parisc
64bit kernel when stracing 32bit applications:
Kernel Fault: Code=15 regs=00000000bafa42b0 (Addr=00000001baf5ab57)
YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI
PSW: 00001000000001101111111100001011 Tainted: G W
r00-03 000000ff0806ff0b 000000004068edc0 00000000401203f8 00000000fb3e2508
r04-07 0000000040686dc0 00000000baf5a800 fffffffffffffffc fffffffffb3e2508
r08-11 00000000baf5a800 000000000004b068 00000000000402b0 0000000000040d68
r12-15 0000000000042a9c 0000000000040a9c 0000000000040d60 0000000000042e9c
r16-19 000000000004b060 000000000004b058 0000000000042d9c ffffffffffffffff
r20-23 000000000800000b 0000000000000000 000000000800000b fffffffffb3e2508
r24-27 00000000fffffffc 0000000000000003 00000000fffffffc 0000000040686dc0
r28-31 00000001baf5a7ff 00000000bafa4280 00000000bafa42b0 00000000000001d7
sr00-03 0000000000fca000 0000000000000000 0000000000000000 0000000000fca000
sr04-07 0000000000000000 0000000000000000 0000000000000000 0000000000000000
IASQ: 0000000000000000 0000000000000000 IAOQ: 0000000040120400 0000000040120404
IIR: 4b9a06b0 ISR: 0000000000000000 IOR: 00000001baf5ab57
CPU: 0 CR30: 00000000bafa4000 CR31: 00000000d22344e0
ORIG_R28: 00000000fb3e2248
IAOQ[0]: compat_arch_ptrace+0xb8/0x160
IAOQ[1]: compat_arch_ptrace+0xbc/0x160
RP(r2): compat_arch_ptrace+0xb0/0x160
Backtrace:
[<00000000401612ac>] compat_sys_ptrace+0x15c/0x180
[<0000000040104ef8>] syscall_exit+0x0/0x14
The problem is that compat_arch_ptrace() enters with an addr value of
type compat_ulong_t and calls translate_usr_offset() to translate the
address offset into a struct pt_regs offset like this:
addr = translate_usr_offset(addr)
this means that any return value of translate_usr_offset() is stored
back as compat_ulong_t type into the addr variable.
But since translate_usr_offset() returns -1 for invalid offsets, addr
can now get the value 0xffffffff which then fails the next return-value
sanity check and thus the kernel tries to access invalid memory:
if (addr < 0)
break;
Fix this bug by modifying translate_usr_offset() to take and return
values of type compat_ulong_t, and by returning the value
"sizeof(struct pt_regs)" as an error indicator.
Additionally change the sanity check to check for return values
for >= sizeof(struct pt_regs).
This patch survived my compile and run-tests.
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch does the compat_sys_ptrace conversion for parisc.
In addition it does convert the parisc ptrace code to use the
architecture-independent ptrace infrastructure instead of own coding.
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
Identical handlers of PTRACE_DETACH go into ptrace_request().
Not touching compat code.
Not touching archs that don't call ptrace_request.
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove includes of <linux/smp_lock.h> where it is not used/needed.
Suggested by Al Viro.
Builds cleanly on x86_64, i386, alpha, ia64, powerpc, sparc,
sparc64, and arm (all 59 defconfigs).
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add enough arch-specific compat signals code to enable parisc64
to compile and boot out of the mainline tree. There are likely still
many dragons here, but this is a start to squashing the last
big difference between the mainline tree and the parisc-linux tree.
The remaining bugs can be squashed as they come up.
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Fix some compile problems:
- ret wasn't being initialised in all code paths
- I'm pretty sure 'goto out' should have been 'goto out_tsk'
Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
The sys_ptrace boilerplate code (everything outside the big switch
statement for the arch-specific requests) is shared by most architectures.
This patch moves it to kernel/ptrace.c and leaves the arch-specific code as
arch_ptrace.
Some architectures have a too different ptrace so we have to exclude them.
They continue to keep their implementations. For sh64 I had to add a
sh64_ptrace wrapper because it does some initialization on the first call.
For um I removed an ifdefed SUBARCH_PTRACE_SPECIAL block, but
SUBARCH_PTRACE_SPECIAL isn't defined anywhere in the tree.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Paul Mackerras <paulus@samba.org>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Acked-By: David Howells <dhowells@redhat.com>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Make the pid argument a long as on every other arcihtecture. Despite pid_t
beeing a 32bit type even on 64bit parisc this is not an ABI change due to
the parisc calling conventions. And even if it did it wouldn't matter too
much because 64bit userspace on parisc is in an embrionic stage.
Acked-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Convert most of the current code that uses _NSIG directly to instead use
valid_signal(). This avoids gcc -W warnings and off-by-one errors.
Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
