diff --git a/CVE-2025-47711.patch b/CVE-2025-47711.patch new file mode 100644 index 0000000000000000000000000000000000000000..d4302d6aa91b701662abd88d0ea522390f4ed1e9 --- /dev/null +++ b/CVE-2025-47711.patch @@ -0,0 +1,170 @@ +From c3c1950867ea8d9c2108ff066ed9e78dde3cfc3f Mon Sep 17 00:00:00 2001 +From: Eric Blake +Date: Tue, 22 Apr 2025 17:01:12 -0500 +Subject: [PATCH] server: Fix off-by-one for maximum block_status length + [CVE-2025-47711] + +Origin: https://gitlab.com/nbdkit/nbdkit/-/commit/c3c1950867ea8d9c2108ff066ed9e78dde3cfc3f + +There has been an off-by-one bug in the code for .extents since the +introduction of that callback. Remember, internally the code allows +plugins to report on extents with 64-bit lengths, but the protocol +only supports 32-bit block status calls (nbdkit will need to create +plugin version 3 before it can support NBD's newer 64-bit block +status). As such, the server loop intentionally truncates a plugin's +large extent to 2**32-1 bytes. But in the process of checking whether +the loop should exit early, or if any additional extents should be +reported to the client, the server used 'pos > offset+count' instead +of >=, which is one byte too far. If the client has requested exactly +2**32-1 bytes, and the plugin's first extent has that same length, the +code erroneously proceeds on to the plugin's second extent. Worse, if +the plugin's first extent has 2**32 bytes or more, it was truncated to +2**31-1 bytes, but not completely handled, and the failure to exit the +loop early means that the server then fails the assertion: + +nbdkit: ../../server/protocol.c:505: extents_to_block_descriptors: +Assertion `e.length <= length' failed. + +The single-byte fix addresses both symptoms, while the added test +demonstrates both when run on older nbdkit (the protocol violation +when the plugin returns 2**32-1 bytes in the first extent, and the +assertion failure when the plugin returns 2**32 or more bytes in the +first extent). + +The problem can only be triggered by a client request for 2**32-1 +bytes; anything smaller is immune. The problem also does not occur +for plugins that do not return extents information beyond the client's +request, or if the first extent is smaller than the client's request. + +The ability to cause the server to die from an assertion failure can +be used as a denial of service attack against other clients. +Mitigations: if you require the use of TLS, then you can ensure that +you only have trusted clients that won't trigger a block status call +of length 2**32-1 bytes. Also, you can use "--filter=blocksize-policy +blocksize-minimum=512" to reject block status attempts from clients +that are not sector-aligned. + +Fixes: 26455d45 ('server: protocol: Implement Block Status "base:allocation".', v1.11.10) +Reported-by: Nikolay Ivanets +Signed-off-by: Eric Blake +Message-ID: <20250423211953.GR1450@redhat.com> +Reviewed-by: Richard W.M. Jones +(cherry picked from commit e6f96bd1b77c0cc927ce6aeff650b52238304f39) +--- + server/protocol.c | 2 +- + tests/Makefile.am | 2 ++ + tests/test-eval-extents.sh | 71 ++++++++++++++++++++++++++++++++++++++ + 3 files changed, 74 insertions(+), 1 deletion(-) + create mode 100755 tests/test-eval-extents.sh + +diff --git a/server/protocol.c b/server/protocol.c +index 2ac7705..015235c 100644 +--- a/server/protocol.c ++++ b/server/protocol.c +@@ -495,7 +495,7 @@ extents_to_block_descriptors (struct nbdkit_extents *extents, + (*nr_blocks)++; + + pos += length; +- if (pos > offset + count) /* this must be the last block */ ++ if (pos >= offset + count) /* this must be the last block */ + break; + + /* If we reach here then we must have consumed this whole +diff --git a/tests/Makefile.am b/tests/Makefile.am +index c02f541..df17c4c 100644 +--- a/tests/Makefile.am ++++ b/tests/Makefile.am +@@ -697,11 +697,13 @@ TESTS += \ + test-eval.sh \ + test-eval-file.sh \ + test-eval-exports.sh \ ++ test-eval-extents.sh \ + $(NULL) + EXTRA_DIST += \ + test-eval.sh \ + test-eval-file.sh \ + test-eval-exports.sh \ ++ test-eval-extents.sh \ + $(NULL) + + # file plugin test. +diff --git a/tests/test-eval-extents.sh b/tests/test-eval-extents.sh +new file mode 100755 +index 0000000..92b503e +--- /dev/null ++++ b/tests/test-eval-extents.sh +@@ -0,0 +1,71 @@ ++#!/usr/bin/env bash ++# nbdkit ++# Copyright Red Hat ++# ++# Redistribution and use in source and binary forms, with or without ++# modification, are permitted provided that the following conditions are ++# met: ++# ++# * Redistributions of source code must retain the above copyright ++# notice, this list of conditions and the following disclaimer. ++# ++# * Redistributions in binary form must reproduce the above copyright ++# notice, this list of conditions and the following disclaimer in the ++# documentation and/or other materials provided with the distribution. ++# ++# * Neither the name of Red Hat nor the names of its contributors may be ++# used to endorse or promote products derived from this software without ++# specific prior written permission. ++# ++# THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND ++# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, ++# THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A ++# PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR ++# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, ++# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT ++# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF ++# USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ++# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, ++# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT ++# OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF ++# SUCH DAMAGE. ++ ++source ./functions.sh ++set -e ++set -x ++ ++requires_run ++requires_plugin eval ++requires_nbdsh_uri ++requires nbdsh --base-allocation --version ++ ++files="eval-extents.out" ++rm -f $files ++cleanup_fn rm -f $files ++ ++# Trigger an off-by-one bug introduced in v1.11.10 and fixed in v1.43.7 ++export script=' ++def f(context, offset, extents, status): ++ print(extents) ++ ++# First, probe where the server should return 2 extents. ++h.block_status(2**32-1, 2, f) ++ ++# Next, probe where the server has exactly 2**32-1 bytes in its first extent. ++h.block_status(2**32-1, 1, f) ++ ++# Now, probe where the first extent has to be truncated. ++h.block_status(2**32-1, 0, f) ++' ++nbdkit eval \ ++ get_size='echo 5G' \ ++ pread='dd if=/dev/zero count=$3 iflag=count_bytes' \ ++ extents='echo 0 4G 1; echo 4G 1G 2' \ ++ --run 'nbdsh --base-allocation --uri "$uri" -c "$script"' \ ++ > eval-extents.out ++cat eval-extents.out ++diff -u - eval-extents.out < +Date: Tue, 22 Apr 2025 19:53:39 -0500 +Subject: [PATCH] blocksize: Fix 32-bit overflow in .extents [CVE-2025-47712] + +Origin: https://gitlab.com/nbdkit/nbdkit/-/commit/c3ed72811aca5684490b198737b2f0b921741547 + +If the original request is larger than 2**32 - minblock, then we were +calling nbdkit_extents_aligned() with a count that rounded up then +overflowed to 0 instead of the intended 4G because of overflowing a +32-bit type, which in turn causes an assertion failure: + +nbdkit: ../../server/backend.c:814: backend_extents: Assertion `backend_valid_range (c, offset, count)' failed. + +The fix is to force the rounding to be in a 64-bit type from the +get-go. + +The ability for a well-behaved client to cause the server to die from +an assertion failure can be used as a denial of service attack against +other clients. Mitigations: if you requrire the use of TLS, then you +can ensure that you only have trusted clients that won't trigger a +block status call that large. Also, the problem only occurs when +using the blocksize filter, although setting the filter's maxlen +parameter to a smaller value than its default of 2**32-1 does not +help. + +Fixes: 2680be00 ('blocksize: Fix .extents when plugin changes type within minblock', v1.21.16) +Signed-off-by: Eric Blake +Message-ID: <20250423210917.1784789-3-eblake@redhat.com> +Reviewed-by: Richard W.M. Jones +(cherry picked from commit a486f88d1eea653ea88b0bf8804c4825dab25ec7) +--- + filters/blocksize/blocksize.c | 2 +- + 1 files changed, 1 insertions(+), 1 deletions(-) + +diff --git a/filters/blocksize/blocksize.c b/filters/blocksize/blocksize.c +index a6fa00c..73da1c8 100644 +--- a/filters/blocksize/blocksize.c ++++ b/filters/blocksize/blocksize.c +@@ -382,7 +382,7 @@ blocksize_extents (nbdkit_next *next, + return -1; + } + +- if (nbdkit_extents_aligned (next, MIN (ROUND_UP (count, minblock), maxlen), ++ if (nbdkit_extents_aligned (next, MIN (ROUND_UP ((uint64_t) count, minblock), maxlen), + ROUND_DOWN (offset, minblock), flags, minblock, + extents2, err) == -1) + return -1; +-- +2.49.0 + diff --git a/nbdkit.spec b/nbdkit.spec index ed7a66ff44e785ceb5d6172259d81d84daf8f1c7..5af396a10f463de5dd0ddc4d1d71cd476459df26 100644 --- a/nbdkit.spec +++ b/nbdkit.spec @@ -4,13 +4,15 @@ Name: nbdkit Version: 1.29.11 -Release: 1 +Release: 2 Summary: NBD server License: BSD URL: https://github.com/libguestfs/nbdkit Source0: https://download.libguestfs.org/nbdkit/1.29-development/nbdkit-%{version}.tar.gz Source1: https://download.libguestfs.org/nbdkit/1.29-development/nbdkit-%{version}.tar.gz.sig Source2: libguestfs.keyring +Patch0: CVE-2025-47711.patch +Patch1: CVE-2025-47712.patch %if 0%{patches_touch_autotools} BuildRequires: autoconf, automake, libtool %endif @@ -474,6 +476,9 @@ popd %{_mandir}/man3/NBDKit.3.gz %changelog +* Fri Jun 20 2025 wangkai <13474090681@163.com> - 1.29.11-2 +- Fix CVE-2025-47711, CVE-2025-47712 + * Thu Dec 30 2021 liyanan - 1.29.11-1 - update to 1.29.11