diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2018-04-20 14:03:18 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-05-16 10:06:52 +0200 |
| commit | f21e5918a98369190d4e167b011a5e9a62e9f2ad (patch) | |
| tree | 482d17936f5497ff550f1676d5bd6af1fe35727e | |
| parent | ae5751bee1e21dd17de021e7706abbab0b5e49da (diff) | |
perf/core: Fix possible Spectre-v1 indexing for ->aux_pages[]
commit 4411ec1d1993e8dbff2898390e3fed280d88e446 upstream.
> kernel/events/ring_buffer.c:871 perf_mmap_to_page() warn: potential spectre issue 'rb->aux_pages'
Userspace controls @pgoff through the fault address. Sanitize the
array index before doing the array dereference.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | kernel/events/ring_buffer.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c index 014b69528194..58013ef228a1 100644 --- a/kernel/events/ring_buffer.c +++ b/kernel/events/ring_buffer.c @@ -14,6 +14,7 @@ #include <linux/slab.h> #include <linux/circ_buf.h> #include <linux/poll.h> +#include <linux/nospec.h> #include "internal.h" @@ -779,8 +780,10 @@ perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff) return NULL; /* AUX space */ - if (pgoff >= rb->aux_pgoff) - return virt_to_page(rb->aux_pages[pgoff - rb->aux_pgoff]); + if (pgoff >= rb->aux_pgoff) { + int aux_pgoff = array_index_nospec(pgoff - rb->aux_pgoff, rb->aux_nr_pages); + return virt_to_page(rb->aux_pages[aux_pgoff]); + } } return __perf_mmap_to_page(rb, pgoff); |