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authorCatalin Marinas <catalin.marinas@arm.com>2016-07-21 10:54:54 +0100
committerAlex Shi <alex.shi@linaro.org>2016-10-20 15:38:13 +0800
commit717a1bff724bd2db1a901e3afe00fe27a6e5551c (patch)
tree78f866692eba11de685e62c11f0879fd95ba98c9
parenta5d55dd10f2a061849e7a665aa4b16bf258d9d0a (diff)
downloadlinux-linaro-stable-717a1bff724bd2db1a901e3afe00fe27a6e5551c.tar.gz
arm64: kprobes: Add KASAN instrumentation around stack accesses
commit f7e35c5ba4322838ce84b23a2f1a6d6b7f0b57ec upstream. This patch disables KASAN around the memcpy from/to the kernel or IRQ stacks to avoid warnings like below: BUG: KASAN: stack-out-of-bounds in setjmp_pre_handler+0xe4/0x170 at addr ffff800935cbbbc0 Read of size 128 by task swapper/0/1 page:ffff7e0024d72ec0 count:0 mapcount:0 mapping: (null) index:0x0 flags: 0x1000000000000000() page dumped because: kasan: bad access detected CPU: 4 PID: 1 Comm: swapper/0 Not tainted 4.7.0-rc4+ #1 Hardware name: ARM Juno development board (r0) (DT) Call trace: [<ffff20000808ad88>] dump_backtrace+0x0/0x280 [<ffff20000808b01c>] show_stack+0x14/0x20 [<ffff200008563a64>] dump_stack+0xa4/0xc8 [<ffff20000824a1fc>] kasan_report_error+0x4fc/0x528 [<ffff20000824a5e8>] kasan_report+0x40/0x48 [<ffff20000824948c>] check_memory_region+0x144/0x1a0 [<ffff200008249814>] memcpy+0x34/0x68 [<ffff200008c3ee2c>] setjmp_pre_handler+0xe4/0x170 [<ffff200008c3ec5c>] kprobe_breakpoint_handler+0xec/0x1d8 [<ffff2000080853a4>] brk_handler+0x5c/0xa0 [<ffff2000080813f0>] do_debug_exception+0xa0/0x138 Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: David A. Long <dave.long@linaro.org>
-rw-r--r--arch/arm64/kernel/probes/kprobes.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c
index 235455412caa..6487b62fe002 100644
--- a/arch/arm64/kernel/probes/kprobes.c
+++ b/arch/arm64/kernel/probes/kprobes.c
@@ -16,6 +16,7 @@
* General Public License for more details.
*
*/
+#include <linux/kasan.h>
#include <linux/kernel.h>
#include <linux/kprobes.h>
#include <linux/module.h>
@@ -495,8 +496,10 @@ int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
* we also save and restore enough stack bytes to cover
* the argument area.
*/
+ kasan_disable_current();
memcpy(kcb->jprobes_stack, (void *)stack_ptr,
min_stack_size(stack_ptr));
+ kasan_enable_current();
instruction_pointer_set(regs, (unsigned long) jp->entry);
preempt_disable();
@@ -548,8 +551,10 @@ int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
}
unpause_graph_tracing();
*regs = kcb->jprobe_saved_regs;
+ kasan_disable_current();
memcpy((void *)stack_addr, kcb->jprobes_stack,
min_stack_size(stack_addr));
+ kasan_enable_current();
preempt_enable_no_resched();
return 1;
}