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authorWill Deacon <will.deacon@arm.com>2018-02-19 16:46:57 +0000
committerWill Deacon <will.deacon@arm.com>2018-02-19 17:07:12 +0000
commita06f818a70de21b4b3b4186816094208fc7accf9 (patch)
tree4b5ec2e02b5589b5ed8b7541b465c64985ae729d
parent1962682d2b2fbe6cfa995a85c53c069fadda473e (diff)
arm64: __show_regs: Only resolve kernel symbols when running at EL1
__show_regs pretty prints PC and LR by attempting to map them to kernel function names to improve the utility of crash reports. Unfortunately, this mapping is applied even when the pt_regs corresponds to user mode, resulting in a KASLR oracle. Avoid this issue by only looking up the function symbols when the register state indicates that we're actually running at EL1. Cc: <stable@vger.kernel.org> Reported-by: NCSC Security <security@ncsc.gov.uk> Signed-off-by: Will Deacon <will.deacon@arm.com>
-rw-r--r--arch/arm64/kernel/process.c11
1 files changed, 9 insertions, 2 deletions
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index ad8aeb098b31..c0da6efe5465 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -220,8 +220,15 @@ void __show_regs(struct pt_regs *regs)
show_regs_print_info(KERN_DEFAULT);
print_pstate(regs);
- printk("pc : %pS\n", (void *)regs->pc);
- printk("lr : %pS\n", (void *)lr);
+
+ if (!user_mode(regs)) {
+ printk("pc : %pS\n", (void *)regs->pc);
+ printk("lr : %pS\n", (void *)lr);
+ } else {
+ printk("pc : %016llx\n", regs->pc);
+ printk("lr : %016llx\n", lr);
+ }
+
printk("sp : %016llx\n", sp);
i = top_reg;