This is a note to let you know that I've just added the patch titled
[PATCH stable/4.14 11/14] bpf: force strict alignment checks for stack pointers
to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: bpf-force-strict-alignment-checks-for-stack-pointers.patch and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From foo@baz Fri Dec 22 16:47:02 CET 2017
From: Daniel Borkmann daniel@iogearbox.net Date: Fri, 22 Dec 2017 16:23:09 +0100 Subject: [PATCH stable/4.14 11/14] bpf: force strict alignment checks for stack pointers To: gregkh@linuxfoundation.org Cc: ast@kernel.org, daniel@iogearbox.net, jannh@google.com, stable@vger.kernel.org Message-ID: 20171222152312.2945-12-daniel@iogearbox.net
From: Daniel Borkmann daniel@iogearbox.net
From: Jann Horn jannh@google.com
[ Upstream commit a5ec6ae161d72f01411169a938fa5f8baea16e8f ]
Force strict alignment checks for stack pointers because the tracking of stack spills relies on it; unaligned stack accesses can lead to corruption of spilled registers, which is exploitable.
Fixes: f1174f77b50c ("bpf/verifier: rework value tracking") Signed-off-by: Jann Horn jannh@google.com Signed-off-by: Alexei Starovoitov ast@kernel.org Signed-off-by: Daniel Borkmann daniel@iogearbox.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- kernel/bpf/verifier.c | 5 +++++ 1 file changed, 5 insertions(+)
--- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -1061,6 +1061,11 @@ static int check_ptr_alignment(struct bp break; case PTR_TO_STACK: pointer_desc = "stack "; + /* The stack spill tracking logic in check_stack_write() + * and check_stack_read() relies on stack accesses being + * aligned. + */ + strict = true; break; default: break;
Patches currently in stable-queue which might be from daniel@iogearbox.net are
queue-4.14/bpf-fix-integer-overflows.patch queue-4.14/bpf-fix-branch-pruning-logic.patch queue-4.14/bpf-s390x-do-not-reload-skb-pointers-in-non-skb-context.patch queue-4.14/bpf-sparc-fix-usage-of-wrong-reg-for-load_skb_regs-after-call.patch queue-4.14/bpf-fix-incorrect-tracking-of-register-size-truncation.patch queue-4.14/bpf-don-t-prune-branches-when-a-scalar-is-replaced-with-a-pointer.patch queue-4.14/bpf-verifier-fix-bounds-calculation-on-bpf_rsh.patch queue-4.14/selftests-bpf-add-tests-for-recent-bugfixes.patch queue-4.14/bpf-fix-corruption-on-concurrent-perf_event_output-calls.patch queue-4.14/bpf-fix-incorrect-sign-extension-in-check_alu_op.patch queue-4.14/bpf-ppc64-do-not-reload-skb-pointers-in-non-skb-context.patch queue-4.14/bpf-fix-missing-error-return-in-check_stack_boundary.patch queue-4.14/bpf-force-strict-alignment-checks-for-stack-pointers.patch queue-4.14/bpf-fix-32-bit-alu-op-verification.patch queue-4.14/bpf-fix-build-issues-on-um-due-to-mising-bpf_perf_event.h.patch