lkml.org 
[lkml]   [2018]   [Feb]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4.15 63/64] arm64: __show_regs: Only resolve kernel symbols when running at EL1
Date
4.15-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Will Deacon <will.deacon@arm.com>

commit a06f818a70de21b4b3b4186816094208fc7accf9 upstream.

__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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/arm64/kernel/process.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)

--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -221,8 +221,15 @@ void __show_regs(struct pt_regs *regs)

show_regs_print_info(KERN_DEFAULT);
print_pstate(regs);
- print_symbol("pc : %s\n", regs->pc);
- print_symbol("lr : %s\n", lr);
+
+ if (!user_mode(regs)) {
+ print_symbol("pc : %s\n", regs->pc);
+ print_symbol("lr : %s\n", lr);
+ } else {
+ printk("pc : %016llx\n", regs->pc);
+ printk("lr : %016llx\n", lr);
+ }
+
printk("sp : %016llx\n", sp);

i = top_reg;

\
 
 \ /
  Last update: 2018-02-26 21:30    [W:0.122 / U:2.816 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site