Commit-ID: 554086d85e71f30abe46fc014fea31929a7c6a8a Gitweb: http://git.kernel.org/tip/554086d85e71f30abe46fc014fea31929a7c6a8a Author: Andy Lutomirski <luto@xxxxxxxxxxxxxx> AuthorDate: Mon, 23 Jun 2014 14:22:15 -0700 Committer: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx> CommitDate: Mon, 23 Jun 2014 14:59:26 -0700 x86_32, entry: Do syscall exit work on badsys (CVE-2014-4508) The bad syscall nr paths are their own incomprehensible route through the entry control flow. Rearrange them to work just like syscalls that return -ENOSYS. This fixes an OOPS in the audit code when fast-path auditing is enabled and sysenter gets a bad syscall nr (CVE-2014-4508). This has probably been broken since Linux 2.6.27: af0575bba0 i386 syscall audit fast-path Cc: stable@xxxxxxxxxxxxxxx Cc: Roland McGrath <roland@xxxxxxxxxx> Reported-by: Toralf Förster <toralf.foerster@xxxxxx> Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxxxxxx> Link: http://lkml.kernel.org/r/e09c499eade6fc321266dd6b54da7beb28d6991c.1403558229.git.luto@xxxxxxxxxxxxxx Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx> --- arch/x86/kernel/entry_32.S | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S index f0da82b..dbaa23e 100644 --- a/arch/x86/kernel/entry_32.S +++ b/arch/x86/kernel/entry_32.S @@ -423,9 +423,10 @@ sysenter_past_esp: jnz sysenter_audit sysenter_do_call: cmpl $(NR_syscalls), %eax - jae syscall_badsys + jae sysenter_badsys call *sys_call_table(,%eax,4) movl %eax,PT_EAX(%esp) +sysenter_after_call: LOCKDEP_SYS_EXIT DISABLE_INTERRUPTS(CLBR_ANY) TRACE_IRQS_OFF @@ -675,7 +676,12 @@ END(syscall_fault) syscall_badsys: movl $-ENOSYS,PT_EAX(%esp) - jmp resume_userspace + jmp syscall_exit +END(syscall_badsys) + +sysenter_badsys: + movl $-ENOSYS,PT_EAX(%esp) + jmp sysenter_after_call END(syscall_badsys) CFI_ENDPROC -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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