CVE-2025-47711

NBD (Network Block Device) is a protocol for accessing Block Devices (hard disks and disk-like things) over a Network. nbdkit is a toolkit for creating NBD servers. The key features are: * Multithreaded NBD server written in C with good performance. * Minimal dependencies for the basic server. * Liberal license (BSD) allows nbdkit to be linked to proprietary libraries or included in proprietary code. * Well-documented, simple plugin API with a stable ABI guarantee. Lets you export “unconventional” block devices easily. * You can write plugins in C, Lua, Perl, Python, OCaml, Ruby, Rust, shell script or Tcl. * Filters can be stacked in front of plugins to transform the output.

Security Fix(es):

There's a flaw in the nbdkit server when handling responses from its plugins regarding the status of data blocks. If a client makes a specific request for a very large data range, and a plugin responds with an even larger single block, the nbdkit server can encounter a critical internal error, leading to a denial-of-service.(CVE-2025-47711)

A flaw exists in the nbdkit "blocksize" filter that can be triggered by a specific type of client request. When a client requests block status information for a very large data range, exceeding a certain limit, it causes an internal error in the nbdkit, leading to a denial of service.(CVE-2025-47712)

NBD (Network Block Device) is a protocol for accessing Block Devices (hard disks and disk-like things) over a Network. nbdkit is a toolkit for creating NBD servers. The key features are: * Multithreaded NBD server written in C with good performance. * Minimal dependencies for the basic server. * Liberal license (BSD) allows nbdkit to be linked to proprietary libraries or included in proprietary code. * Well-documented, simple plugin API with a stable ABI guarantee. Lets you export “unconventional” block devices easily. * You can write plugins in C, Lua, Perl, Python, OCaml, Ruby, Rust, shell script or Tcl. * Filters can be stacked in front of plugins to transform the output.

Security Fix(es):

There's a flaw in the nbdkit server when handling responses from its plugins regarding the status of data blocks. If a client makes a specific request for a very large data range, and a plugin responds with an even larger single block, the nbdkit server can encounter a critical internal error, leading to a denial-of-service.(CVE-2025-47711)

A flaw exists in the nbdkit "blocksize" filter that can be triggered by a specific type of client request. When a client requests block status information for a very large data range, exceeding a certain limit, it causes an internal error in the nbdkit, leading to a denial of service.(CVE-2025-47712)

NBD (Network Block Device) is a protocol for accessing Block Devices (hard disks and disk-like things) over a Network. nbdkit is a toolkit for creating NBD servers. The key features are: * Multithreaded NBD server written in C with good performance. * Minimal dependencies for the basic server. * Liberal license (BSD) allows nbdkit to be linked to proprietary libraries or included in proprietary code. * Well-documented, simple plugin API with a stable ABI guarantee. Lets you export “unconventional” block devices easily. * You can write plugins in C, Lua, Perl, Python, OCaml, Ruby, Rust, shell script or Tcl. * Filters can be stacked in front of plugins to transform the output.

Security Fix(es):

There's a flaw in the nbdkit server when handling responses from its plugins regarding the status of data blocks. If a client makes a specific request for a very large data range, and a plugin responds with an even larger single block, the nbdkit server can encounter a critical internal error, leading to a denial-of-service.(CVE-2025-47711)

A flaw exists in the nbdkit "blocksize" filter that can be triggered by a specific type of client request. When a client requests block status information for a very large data range, exceeding a certain limit, it causes an internal error in the nbdkit, leading to a denial of service.(CVE-2025-47712)

NBD (Network Block Device) is a protocol for accessing Block Devices (hard disks and disk-like things) over a Network. nbdkit is a toolkit for creating NBD servers. The key features are: * Multithreaded NBD server written in C with good performance. * Minimal dependencies for the basic server. * Liberal license (BSD) allows nbdkit to be linked to proprietary libraries or included in proprietary code. * Well-documented, simple plugin API with a stable ABI guarantee. Lets you export “unconventional” block devices easily. * You can write plugins in C, Lua, Perl, Python, OCaml, Ruby, Rust, shell script or Tcl. * Filters can be stacked in front of plugins to transform the output.

Security Fix(es):

There's a flaw in the nbdkit server when handling responses from its plugins regarding the status of data blocks. If a client makes a specific request for a very large data range, and a plugin responds with an even larger single block, the nbdkit server can encounter a critical internal error, leading to a denial-of-service.(CVE-2025-47711)

A flaw exists in the nbdkit "blocksize" filter that can be triggered by a specific type of client request. When a client requests block status information for a very large data range, exceeding a certain limit, it causes an internal error in the nbdkit, leading to a denial of service.(CVE-2025-47712)

NBD (Network Block Device) is a protocol for accessing Block Devices (hard disks and disk-like things) over a Network. nbdkit is a toolkit for creating NBD servers. The key features are: * Multithreaded NBD server written in C with good performance. * Minimal dependencies for the basic server. * Liberal license (BSD) allows nbdkit to be linked to proprietary libraries or included in proprietary code. * Well-documented, simple plugin API with a stable ABI guarantee. Lets you export “unconventional” block devices easily. * You can write plugins in C, Lua, Perl, Python, OCaml, Ruby, Rust, shell script or Tcl. * Filters can be stacked in front of plugins to transform the output.

Security Fix(es):

There's a flaw in the nbdkit server when handling responses from its plugins regarding the status of data blocks. If a client makes a specific request for a very large data range, and a plugin responds with an even larger single block, the nbdkit server can encounter a critical internal error, leading to a denial-of-service.(CVE-2025-47711)

A flaw exists in the nbdkit "blocksize" filter that can be triggered by a specific type of client request. When a client requests block status information for a very large data range, exceeding a certain limit, it causes an internal error in the nbdkit, leading to a denial of service.(CVE-2025-47712)

There's a flaw in the nbdkit server when handling responses from its plugins regarding the status of data blocks. If a client makes a specific request for a very large data range, and a plugin responds with an even larger single block, the nbdkit server can encounter a critical internal error, leading to a denial-of-service.

There's a flaw in the nbdkit server when handling responses from its plugins regarding the status of data blocks. If a client makes a specific request for a very large data range, and a plugin responds with an even larger single block, the nbdkit server can encounter a critical internal error, leading to a denial-of-service.

There's a flaw in the nbdkit server when handling responses from its plugins regarding the status of data blocks. If a client makes a specific request for a very large data range, and a plugin responds with an even larger single block, the nbdkit server can encounter a critical internal error, leading to a denial-of-service.

• CVE-2025-47711: fix off-by-one for maximum block_status length

These are all security issues fixed in the nbdkit-1.42.3-1.1 package on the GA media of openSUSE Tumbleweed.

This update for nbdkit fixes the following issues:

Update to version 1.40.6.

Security fixes:

• CVE-2025-47712: integer overflow in blocksize filter when processing client block status requests larger than 2**32 will trigger an assertion failure and cause a denial-of-service. (bsc#1243108).
• CVE-2025-47711: off-by-one error when processing block status results from plugins on behalf of an NBD client may trigger an assertion failure and cause a denial of service (bsc#1243110).

Other fixes and changes:

• golang: Support GCC 15.
• openbsd: curl: Include pthread.h.
• rust: Fix 'overindented' list in comment.
• rust: Declare explicit extern 'C' API.
• plugins/rust: Use CStr literals for static strings.
• vddk: do_extents: Avoid reading partial chunk beyond the end of the disk.
• vddk: do_extents: Exit the function if we hit req_one condition.
• vddk: do_extents: Mark some local variables const.
• vddk: Cache the disk size in the handle.
• vddk: Include <stdbool.h>.
• python: examples: Fix comment above API_VERSION constant.
• tcl: Fix for Tcl 9.0 compatibility.
• plugins/ocaml/NBDKit.ml: Sort bindings into order.
• ocaml: Don't call abort if caml_c_thread_unregister fails.
• ocaml: Use real addresses instead of (void*)<constant>s.
• evil: Link to nbdkit_parse_probability(3).

This update for nbdkit fixes the following issues:

Update to version 1.36.5.

Security fixes:

• CVE-2025-47712: integer overflow in blocksize filter when processing client block status requests larger than 2**32 will trigger an assertion failure and cause a denial-of-service. (bsc#1243108).
• CVE-2025-47711: off-by-one error when processing block status results from plugins on behalf of an NBD client may trigger an assertion failure and cause a denial of service (bsc#1243110).

Other fixes and changes:

• tests: Add test-blkio.sh to unconditional EXTRA_DIST rule.
• Revert 'valgrind: Add suppression for liblzma bug'.
• vddk: Move 'Unknown error' information to the manual.
• ocaml Add better comments to the example plugin.
• ocaml: Simplify pread operation.
• ocaml: Define a struct handle to hold the OCaml handle.
• ocaml: Add OCaml version to --dump-plugin output.
• ocaml: Print callback name when an exception is printed.
• ocaml: Combine all exception printing into a single macro.