user/sven/linux.git/kernel, branch v4.14.130

tracing: Silence GCC 9 array bounds warning

2019-06-25T03:36:50Z

commit 0c97bf863efce63d6ab7971dad811601e6171d2f upstream. Starting with GCC 9, -Warray-bounds detects cases when memset is called starting on a member of a struct but the size to be cleared ends up writing over further members. Such a call happens in the trace code to clear, at once, all members after and including `seq` on struct trace_iterator: In function 'memset', inlined from 'ftrace_dump' at kernel/trace/trace.c:8914:3: ./include/linux/string.h:344:9: warning: '__builtin_memset' offset [8505, 8560] from the object at 'iter' is out of the bounds of referenced subobject 'seq' with type 'struct trace_seq' at offset 4368 [-Warray-bounds] 344 | return __builtin_memset(p, c, size); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ In order to avoid GCC complaining about it, we compute the address ourselves by adding the offsetof distance instead of referring directly to the member. Since there are two places doing this clear (trace.c and trace_kdb.c), take the chance to move the workaround into a single place in the internal header. Link: http://lkml.kernel.org/r/20190523124535.GA12931@gmail.com Signed-off-by: Miguel Ojeda [ Removed unnecessary parenthesis around "iter" ] Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman

perf/ring-buffer: Always use {READ,WRITE}_ONCE() for rb->user_page data

2019-06-22T06:16:16Z

[ Upstream commit 4d839dd9e4356bbacf3eb0ab13a549b83b008c21 ] We must use {READ,WRITE}_ONCE() on rb->user_page data such that concurrent usage will see whole values. A few key sites were missing this. Suggested-by: Yabin Cui Signed-off-by: Peter Zijlstra (Intel) Cc: Alexander Shishkin Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Thomas Gleixner Cc: Vince Weaver Cc: acme@kernel.org Cc: mark.rutland@arm.com Cc: namhyung@kernel.org Fixes: 7b732a750477 ("perf_counter: new output ABI - part 1") Link: http://lkml.kernel.org/r/20190517115418.394192145@infradead.org Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin

perf/ring_buffer: Add ordering to rb->nest increment

2019-06-22T06:16:16Z

[ Upstream commit 3f9fbe9bd86c534eba2faf5d840fd44c6049f50e ] Similar to how decrementing rb->next too early can cause data_head to (temporarily) be observed to go backward, so too can this happen when we increment too late. This barrier() ensures the rb->head load happens after the increment, both the one in the 'goto again' path, as the one from perf_output_get_handle() -- albeit very unlikely to matter for the latter. Suggested-by: Yabin Cui Signed-off-by: Peter Zijlstra (Intel) Cc: Alexander Shishkin Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Thomas Gleixner Cc: Vince Weaver Cc: acme@kernel.org Cc: mark.rutland@arm.com Cc: namhyung@kernel.org Fixes: ef60777c9abd ("perf: Optimize the perf_output() path by removing IRQ-disables") Link: http://lkml.kernel.org/r/20190517115418.309516009@infradead.org Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin

perf/ring_buffer: Fix exposing a temporarily decreased data_head

2019-06-22T06:16:16Z

[ Upstream commit 1b038c6e05ff70a1e66e3e571c2e6106bdb75f53 ] In perf_output_put_handle(), an IRQ/NMI can happen in below location and write records to the same ring buffer: ... local_dec_and_test(&rb->nest) ... <-- an IRQ/NMI can happen here rb->user_page->data_head = head; ... In this case, a value A is written to data_head in the IRQ, then a value B is written to data_head after the IRQ. And A > B. As a result, data_head is temporarily decreased from A to B. And a reader may see data_head < data_tail if it read the buffer frequently enough, which creates unexpected behaviors. This can be fixed by moving dec(&rb->nest) to after updating data_head, which prevents the IRQ/NMI above from updating data_head. [ Split up by peterz. ] Signed-off-by: Yabin Cui Signed-off-by: Peter Zijlstra (Intel) Cc: Alexander Shishkin Cc: Arnaldo Carvalho de Melo Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Linus Torvalds Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Thomas Gleixner Cc: Vince Weaver Cc: mark.rutland@arm.com Fixes: ef60777c9abd ("perf: Optimize the perf_output() path by removing IRQ-disables") Link: http://lkml.kernel.org/r/20190517115418.224478157@infradead.org Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin

x86/uaccess, kcov: Disable stack protector

2019-06-19T06:20:56Z

[ Upstream commit 40ea97290b08be2e038b31cbb33097d1145e8169 ] New tooling noticed this mishap: kernel/kcov.o: warning: objtool: write_comp_data()+0x138: call to __stack_chk_fail() with UACCESS enabled kernel/kcov.o: warning: objtool: __sanitizer_cov_trace_pc()+0xd9: call to __stack_chk_fail() with UACCESS enabled All the other instrumentation (KASAN,UBSAN) also have stack protector disabled. Signed-off-by: Peter Zijlstra (Intel) Cc: Borislav Petkov Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin

ptrace: restore smp_rmb() in __ptrace_may_access()

2019-06-19T06:20:55Z

commit f6581f5b55141a95657ef5742cf6a6bfa20a109f upstream. Restore the read memory barrier in __ptrace_may_access() that was deleted a couple years ago. Also add comments on this barrier and the one it pairs with to explain why they're there (as far as I understand). Fixes: bfedb589252c ("mm: Add a user_ns owner to mm_struct and fix ptrace permission checks") Cc: stable@vger.kernel.org Acked-by: Kees Cook Acked-by: Oleg Nesterov Signed-off-by: Jann Horn Signed-off-by: Eric W. Biederman Signed-off-by: Greg Kroah-Hartman

signal/ptrace: Don't leak unitialized kernel memory with PTRACE_PEEK_SIGINFO

2019-06-19T06:20:54Z

[ Upstream commit f6e2aa91a46d2bc79fce9b93a988dbe7655c90c0 ] Recently syzbot in conjunction with KMSAN reported that ptrace_peek_siginfo can copy an uninitialized siginfo to userspace. Inspecting ptrace_peek_siginfo confirms this. The problem is that off when initialized from args.off can be initialized to a negaive value. At which point the "if (off >= 0)" test to see if off became negative fails because off started off negative. Prevent the core problem by adding a variable found that is only true if a siginfo is found and copied to a temporary in preparation for being copied to userspace. Prevent args.off from being truncated when being assigned to off by testing that off is <= the maximum possible value of off. Convert off to an unsigned long so that we should not have to truncate args.off, we have well defined overflow behavior so if we add another check we won't risk fighting undefined compiler behavior, and so that we have a type whose maximum value is easy to test for. Cc: Andrei Vagin Cc: stable@vger.kernel.org Reported-by: syzbot+0d602a1b0d8c95bdf299@syzkaller.appspotmail.com Fixes: 84c751bd4aeb ("ptrace: add ability to retrieve signals without removing from a queue (v4)") Signed-off-by: "Eric W. Biederman" Signed-off-by: Sasha Levin

ntp: Allow TAI-UTC offset to be set to zero

2019-06-15T09:54:53Z

[ Upstream commit fdc6bae940ee9eb869e493990540098b8c0fd6ab ] The ADJ_TAI adjtimex mode sets the TAI-UTC offset of the system clock. It is typically set by NTP/PTP implementations and it is automatically updated by the kernel on leap seconds. The initial value is zero (which applications may interpret as unknown), but this value cannot be set by adjtimex. This limitation seems to go back to the original "nanokernel" implementation by David Mills. Change the ADJ_TAI check to accept zero as a valid TAI-UTC offset in order to allow setting it back to the initial value. Fixes: 153b5d054ac2 ("ntp: support for TAI") Suggested-by: Ondrej Mosnacek Signed-off-by: Miroslav Lichvar Signed-off-by: Thomas Gleixner Cc: John Stultz Cc: Richard Cochran Cc: Prarit Bhargava Link: https://lkml.kernel.org/r/20190417084833.7401-1-mlichvar@redhat.com Signed-off-by: Sasha Levin

kernel/sys.c: prctl: fix false positive in validate_prctl_map()

2019-06-15T09:54:52Z

[ Upstream commit a9e73998f9d705c94a8dca9687633adc0f24a19a ] While validating new map we require the @start_data to be strictly less than @end_data, which is fine for regular applications (this is why this nit didn't trigger for that long). These members are set from executable loaders such as elf handers, still it is pretty valid to have a loadable data section with zero size in file, in such case the start_data is equal to end_data once kernel loader finishes. As a result when we're trying to restore such programs the procedure fails and the kernel returns -EINVAL. From the image dump of a program: | "mm_start_code": "0x400000", | "mm_end_code": "0x8f5fb4", | "mm_start_data": "0xf1bfb0", | "mm_end_data": "0xf1bfb0", Thus we need to change validate_prctl_map from strictly less to less or equal operator use. Link: http://lkml.kernel.org/r/20190408143554.GY1421@uranus.lan Fixes: f606b77f1a9e3 ("prctl: PR_SET_MM -- introduce PR_SET_MM_MAP operation") Signed-off-by: Cyrill Gorcunov Cc: Andrey Vagin Cc: Dmitry Safonov <0x7f454c46@gmail.com> Cc: Pavel Emelyanov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

sysctl: return -EINVAL if val violates minmax

2019-06-15T09:54:51Z

[ Upstream commit e260ad01f0aa9e96b5386d5cd7184afd949dc457 ] Currently when userspace gives us a values that overflow e.g. file-max and other callers of __do_proc_doulongvec_minmax() we simply ignore the new value and leave the current value untouched. This can be problematic as it gives the illusion that the limit has indeed be bumped when in fact it failed. This commit makes sure to return EINVAL when an overflow is detected. Please note that this is a userspace facing change. Link: http://lkml.kernel.org/r/20190210203943.8227-4-christian@brauner.io Signed-off-by: Christian Brauner Acked-by: Luis Chamberlain Cc: Kees Cook Cc: Alexey Dobriyan Cc: Al Viro Cc: Dominik Brodowski Cc: "Eric W. Biederman" Cc: Joe Lawrence Cc: Waiman Long Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin