lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Thu, 18 Jun 2015 12:08:40 -0700 From: Andy Lutomirski <luto@...nel.org> To: x86@...nel.org, linux-kernel@...r.kernel.org Cc: Frédéric Weisbecker <fweisbec@...il.com>, Rik van Riel <riel@...hat.com>, Oleg Nesterov <oleg@...hat.com>, Denys Vlasenko <vda.linux@...glemail.com>, Borislav Petkov <bp@...en8.de>, Kees Cook <keescook@...omium.org>, Brian Gerst <brgerst@...il.com>, paulmck@...ux.vnet.ibm.com, Andy Lutomirski <luto@...nel.org> Subject: [PATCH v2 08/14] x86/entry/64: Really create an error-entry-from-usermode code path In 539f51136500 ("x86/asm/entry/64: Disentangle error_entry/exit gsbase/ebx/usermode code"), I arranged the code slightly wrong -- IRET faults would skip the code path that was intended to execute on all error entries from user mode. Fix it up. This does not fix a bug, but we'll need it, and it slightly shrinks the code. Signed-off-by: Andy Lutomirski <luto@...nel.org> --- arch/x86/entry/entry_64.S | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index 3bb2c4302df1..33acc3dcc281 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -1145,7 +1145,11 @@ ENTRY(error_entry) testb $3, CS+8(%rsp) jz error_kernelspace - /* We entered from user mode */ +error_entry_from_usermode: + /* + * We entered from user mode or we're pretending to have entered + * from user mode due to an IRET fault. + */ SWAPGS error_entry_done: @@ -1174,8 +1178,7 @@ error_kernelspace: * gsbase and proceed. We'll fix up the exception and land in * gs_change's error handler with kernel gsbase. */ - SWAPGS - jmp error_entry_done + jmp error_entry_from_usermode bstep_iret: /* Fix truncated RIP */ -- 2.4.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists