From 7a82f89de92aac5a244d3735b2bd162c1147620c Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Wed, 9 Feb 2022 14:49:38 -0500 Subject: [PATCH] audit: don't deref the syscall args when checking the openat2 open_how::flags As reported by Jeff, dereferencing the openat2 syscall argument in audit_match_perm() to obtain the open_how::flags can result in an oops/page-fault. This patch fixes this by using the open_how struct that we store in the audit_context with audit_openat2_how(). Independent of this patch, Richard Guy Briggs posted a similar patch to the audit mailing list roughly 40 minutes after this patch was posted. Cc: stable@vger.kernel.org Fixes: 1c30e3af8a79 ("audit: add support for the openat2 syscall") Reported-by: Jeff Mahoney Signed-off-by: Paul Moore --- kernel/auditsc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/auditsc.c b/kernel/auditsc.c index fce5d43a933f..a83928cbdcb7 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -185,7 +185,7 @@ static int audit_match_perm(struct audit_context *ctx, int mask) case AUDITSC_EXECVE: return mask & AUDIT_PERM_EXEC; case AUDITSC_OPENAT2: - return mask & ACC_MODE((u32)((struct open_how *)ctx->argv[2])->flags); + return mask & ACC_MODE((u32)ctx->openat2.flags); default: return 0; }