From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id B64BE385840E; Tue, 2 Apr 2024 12:02:22 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org B64BE385840E DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1712059342; bh=NtbWHNFy7UA1i/fvbvaEINT5oNXhev0cmxl8tczi4Nk=; h=From:To:Subject:Date:In-Reply-To:References:From; b=FwkhPIC1g18K+4s3PoNNnSsIDoige42zb1gpJVU3MWJ8KtofF8R4Iyil9GHhPe6BR v1K+4R8Nea/SFp8v341v4FOVxBwDRU87jUKxeg9BNzmXW/pkqViKkrJOukU5TB+O2G YqGSLgEzTfQJ+qqrSayVdy8s2N++THjFn9t9+Ff0= From: "fweimer at redhat dot com" To: glibc-bugs@sourceware.org Subject: [Bug dynamic-link/31594] IFUNC relocation resolving should constrain resolver and result Date: Tue, 02 Apr 2024 12:02:21 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: glibc X-Bugzilla-Component: dynamic-link X-Bugzilla-Version: 2.29 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: fweimer at redhat dot com X-Bugzilla-Status: NEW X-Bugzilla-Resolution: X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: unassigned at sourceware dot org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: cc Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://sourceware.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 List-Id: https://sourceware.org/bugzilla/show_bug.cgi?id=3D31594 Florian Weimer changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |fweimer at redhat dot com --- Comment #1 from Florian Weimer --- The resolver has to come from the symbol's object due to the way the addres= s of the resolver is encoded in ELF. A restriction on the address returned from = the resolver would prevent legitimate redirection to another shared object. (Th= ere is some ambiguity whether IFUNC resolvers can refer to external symbols.) I don't see how this is a security-related change. The IFUNC resolver code = is trusted with and without this change. A malicious IFUNC resolver can just return the address of a trampoline in the current object to satisfy any add= ress check. --=20 You are receiving this mail because: You are on the CC list for the bug.=