Commit-ID: ddfdad991e55b65c1cc4ee29502f6dceee04455a Gitweb: http://git.kernel.org/tip/ddfdad991e55b65c1cc4ee29502f6dceee04455a Author: Alexander Shishkin <[email protected]> AuthorDate: Thu, 15 Sep 2016 18:13:51 +0300 Committer: Ingo Molnar <[email protected]> CommitDate: Fri, 16 Sep 2016 11:14:16 +0200
perf/x86/intel/pt: Fix kernel address filter's offset validation 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. Reported-by: Adrian Hunter <[email protected]> Signed-off-by: Alexander Shishkin <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Vince Weaver <[email protected]> Cc: [email protected] # v4.7 Cc: [email protected]#v4.7 Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- 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 5ec0100..1f94963 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))
