Messages in this thread Patch in this message | | | From | Alexander Shishkin <> | Subject | [PATCH v1 2/3] perf/x86/intel/pt: Fix kernel address filter's offset validation | Date | Thu, 15 Sep 2016 18:13:51 +0300 |
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The kernel_ip() filter is used mostly by the DS/LBR code to look at the branch addresses, but Intel PT also uses it to validate the address filter offsets for kernel addresses, for which it is not sufficient: supplying something in bits 64:48 that's not a sign extension of the lower address bits (like 0xf00d000000000000) throws a #GP.
This patch adds address validation for the user supplied kernel filters.
Cc: stable@vger.kernel.org # v4.7 Reported-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> --- arch/x86/events/intel/pt.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/arch/x86/events/intel/pt.c b/arch/x86/events/intel/pt.c index 5ec0100e3f..1f94963a28 100644 --- a/arch/x86/events/intel/pt.c +++ b/arch/x86/events/intel/pt.c @@ -1074,6 +1074,11 @@ static void pt_addr_filters_fini(struct perf_event *event) event->hw.addr_filters = NULL; } +static inline bool valid_kernel_ip(unsigned long ip) +{ + return virt_addr_valid(ip) && kernel_ip(ip); +} + static int pt_event_addr_filters_validate(struct list_head *filters) { struct perf_addr_filter *filter; @@ -1084,7 +1089,7 @@ static int pt_event_addr_filters_validate(struct list_head *filters) if (!filter->range || !filter->size) return -EOPNOTSUPP; - if (!filter->inode && !kernel_ip(filter->offset)) + if (!filter->inode && !valid_kernel_ip(filter->offset)) return -EINVAL; if (++range > pt_cap_get(PT_CAP_num_address_ranges)) -- 2.9.3
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