+ bpf-bpf_seq_printf-handle-potentially-unsafe-format-string-better.patch added to -mm tree

* + bpf-bpf_seq_printf-handle-potentially-unsafe-format-string-better.patch added to -mm tree
@ 2020-06-02 18:31 akpm
  0 siblings, 0 replies; 2+ messages in thread
From: akpm @ 2020-06-02 18:31 UTC (permalink / raw)
  To: akpm, ast, daniel, hch, hpa, mhiramat, mingo, mm-commits, tglx


The patch titled
     Subject: bpf:bpf_seq_printf(): handle potentially unsafe format string better
has been added to the -mm tree.  Its filename is
     bpf-bpf_seq_printf-handle-potentially-unsafe-format-string-better.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/bpf-bpf_seq_printf-handle-potentially-unsafe-format-string-better.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/bpf-bpf_seq_printf-handle-potentially-unsafe-format-string-better.patch

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next and is updated
there every 3-4 working days

------------------------------------------------------
From: Andrew Morton <akpm@linux-foundation.org>
Subject: bpf:bpf_seq_printf(): handle potentially unsafe format string better

User the proper helper for kernel or userspace addresses based on
TASK_SIZE instead of the dangerous strncpy_from_unsafe function.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 kernel/trace/bpf_trace.c |    8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

--- a/kernel/trace/bpf_trace.c~bpf-bpf_seq_printf-handle-potentially-unsafe-format-string-better
+++ a/kernel/trace/bpf_trace.c
@@ -588,15 +588,17 @@ BPF_CALL_5(bpf_seq_printf, struct seq_fi
 		}
 
 		if (fmt[i] == 's') {
+			void *unsafe_ptr;
+
 			/* try our best to copy */
 			if (memcpy_cnt >= MAX_SEQ_PRINTF_MAX_MEMCPY) {
 				err = -E2BIG;
 				goto out;
 			}
 
-			err = strncpy_from_unsafe_strict(bufs->buf[memcpy_cnt],
-							 (void *) (long) args[fmt_cnt],
-							 MAX_SEQ_PRINTF_STR_LEN);
+			unsafe_ptr = (void *)(long)args[fmt_cnt];
+			err = strncpy_from_kernel_nofault(bufs->buf[memcpy_cnt],
+					unsafe_ptr, MAX_SEQ_PRINTF_STR_LEN);
 			if (err < 0)
 				bufs->buf[memcpy_cnt][0] = '\0';
 			params[fmt_cnt] = (u64)(long)bufs->buf[memcpy_cnt];
_

Patches currently in -mm which might be from akpm@linux-foundation.org are

arch-parisc-include-asm-pgtableh-remove-unused-old_pte.patch
mm-slub-add-panic_on_error-to-the-debug-facilities-fix.patch
drivers-tty-serial-sh-scic-suppress-uninitialized-var-warning.patch
mm.patch
mm-free_area_init-allow-defining-max_zone_pfn-in-descending-order-fix-2-fix.patch
mm-page_alloc-skip-waternark_boost-for-atomic-order-0-allocations-fix.patch
arch-kunmap-remove-duplicate-kunmap-implementations-fix.patch
arch-kmap_atomic-consolidate-duplicate-code-checkpatch-fixes.patch
arch-kunmap_atomic-consolidate-duplicate-code-checkpatch-fixes.patch
kmap-consolidate-kmap_prot-definitions-checkpatch-fixes.patch
mm-add-debug_wx-support-fix.patch
riscv-support-debug_wx-fix.patch
mm-replace-zero-length-array-with-flexible-array-member-fix.patch
mm-hugetlb-fix-a-typo-in-comment-manitained-maintained-v2-checkpatch-fixes.patch
lib-make-a-test-module-with-get_count_order-long-fix.patch
seq_file-introduce-define_seq_attribute-helper-macro-checkpatch-fixes.patch
ipc-convert-ipcs_idr-to-xarray-update-fix.patch
linux-next-pre.patch
linux-next-rejects.patch
linux-next-git-rejects.patch
linux-next-post.patch
kernel-add-panic_on_taint-fix.patch
mm-consolidate-pgd_index-and-pgd_offset_k-definitions-fix.patch
mmap-locking-api-convert-mmap_sem-call-sites-missed-by-coccinelle-fix.patch
mmap-locking-api-convert-mmap_sem-call-sites-missed-by-coccinelle-fix-fix.patch
mmap-locking-api-convert-mmap_sem-call-sites-missed-by-coccinelle-fix-fix-fix.patch
mmap-locking-api-rename-mmap_sem-to-mmap_lock-fix.patch
mmap-locking-api-convert-mmap_sem-comments-fix.patch
mmap-locking-api-convert-mmap_sem-comments-fix-fix.patch
mmap-locking-api-convert-mmap_sem-comments-fix-fix-fix.patch
mm-pass-task-and-mm-to-do_madvise.patch
mm-introduce-external-memory-hinting-api-fix-2-fix.patch
mm-support-vector-address-ranges-for-process_madvise-fix-fix-fix-fix-fix.patch
maccess-unify-the-probe-kernel-arch-hooks-fix.patch
bpf-bpf_seq_printf-handle-potentially-unsafe-format-string-better.patch
maccess-always-use-strict-semantics-for-probe_kernel_read-fix.patch
x86-use-non-set_fs-based-maccess-routines-checkpatch-fixes.patch
doc-cgroup-update-note-about-conditions-when-oom-killer-is-invoked-fix.patch
sh-convert-ins-outs-macros-to-inline-functions-checkpatch-fixes.patch
kernel-forkc-export-kernel_thread-to-modules.patch

^ permalink raw reply	[flat|nested] 2+ messages in thread