iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

powerpc/64/syscall: Zero volatile registers when returning

Browse Source 
Kernel addresses and potentially other sensitive data could be leaked
in volatile registers after a syscall.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-27-npiggin@gmail.com
This commit is contained in:
Nicholas Piggin 2020-02-26 03:35:35 +10:00 committed by Michael Ellerman
parent 68b34588e2
commit 993c670a4d
1 changed files with 13 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
arch/powerpc/kernel/entry_64.S
View File

@ -141,6 +141,19 @@ END_FTR_SECTION_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
cmpdi r3,0
bne .Lsyscall_restore_regs
/* Zero volatile regs that may contain sensitive kernel data */
li r0,0
li r4,0
li r5,0
li r6,0
li r7,0
li r8,0
li r9,0
li r10,0
li r11,0
li r12,0
mtctr r0
mtspr SPRN_XER,r0
.Lsyscall_restore_regs_cont:
BEGIN_FTR_SECTION