[Bug 2154120] Re: gpg buggy on RISC-V when vector length /= 128B

[Valentin Haudiquet]

** Description changed:

+ [ Impact ]
+ 
+ GPG is broken on RISC-V when vector length (VLEN) doesn't equal 128B.
+ 
+ This has been fixed upstream:
+ https://github.com/gpg/libgcrypt/commit/3f684fc6ab3ac98320e245a06b3563ad37ec56f5
+ 
+ The upload backports the upstream commit as debian patch.
+ 
+ [ Test Plan ]
+ 
+ Start a RISC-V VM with QEMU, setting vector length to >128.
+ 
+ For this, check
+ 
+ https://documentation.ubuntu.com/hardware-support/boards/how-
+ to/ubuntu_supported/qemu-riscv/
+ 
+ for the full command, and modify it to set vlen:
+ 
+ qemu-system-riscv64 -cpu max,vlen=256 ...
+ 
+ Then, in the VM, run the following commands:
+ 
+ head -c 10000 /dev/urandom > in.bin
+ PW="testpw-correct-horse-battery-staple"
+ gpg --batch --pinentry-mode loopback --passphrase "$PW" --yes --symmetric \
+     --cipher-algo AES256 --output out.gpg in.bin
+ gpg --batch --pinentry-mode loopback --passphrase "$PW" --yes \
+    --decrypt --output dec.bin out.gpg
+ 
+ 
+ This should succeed with only a success message from gpg. However, it currently returns:
+ 
+ gpg: AES256.CFB encrypted data
+ gpg: encrypted with 1 passphrase
+ gpg: WARNING: encrypted message has been manipulated!
+ 
+ It might also be useful to check that basic GPG functionality still
+ works.
+ 
+ [ Where problems could occur ]
+ 
+ Given that this is a change in a library used by GPG, we need to make
+ sure that basic GPG features still work, or that could introduce issues
+ around apt and any other GPG user.
+ 
+ [ Other Info ]
+ 
+ Original bug report:
+ 
  GPG is broken on RISC-V when vector length (VLEN) doesn't equal 128B.
  
  This has been fixed upstream:
  https://github.com/gpg/libgcrypt/commit/3f684fc6ab3ac98320e245a06b3563ad37ec56f5
  
  Test:
  
  head -c 10000 /dev/urandom > in.bin
  PW="testpw-correct-horse-battery-staple"
  gpg --batch --pinentry-mode loopback --passphrase "$PW" --yes --symmetric \
-     --cipher-algo AES256 --output out.gpg in.bin 
+     --cipher-algo AES256 --output out.gpg in.bin
  gpg --batch --pinentry-mode loopback --passphrase "$PW" --yes \
-    --decrypt --output dec.bin out.gpg
+    --decrypt --output dec.bin out.gpg
  if cmp -s in.bin dec.bin; then
-   echo "PASS encrypt/decrypt"
+   echo "PASS encrypt/decrypt"
  else
-   echo "MISMATCH"
+   echo "MISMATCH"
  fi
  
  Run this on x86 it works fine but run it on SpacemiT K3 with VLEN=256 it
  fails.
  
  ProblemType: Bug
  DistroRelease: Ubuntu 26.04
  Package: gpg 2.4.8-4ubuntu3
  Uname: Linux 6.18.3-5-spacemit-generic riscv64
  ApportVersion: 2.34.0-0ubuntu2
  Architecture: riscv64
  CasperMD5CheckResult: unknown
  CloudArchitecture: riscv64
  CloudID: nocloud
  CloudName: unknown
  CloudPlatform: nocloud
  CloudSubPlatform: config-disk (/dev/sda2)
  Date: Sun May 24 10:40:29 2026
  ProcEnviron:
-  LANG=C.UTF-8
-  PATH=(custom, no user)
-  SHELL=/bin/bash
-  TERM=tmux-256color
-  XDG_RUNTIME_DIR=<set>
+  LANG=C.UTF-8
+  PATH=(custom, no user)
+  SHELL=/bin/bash
+  TERM=tmux-256color
+  XDG_RUNTIME_DIR=<set>
  SourcePackage: gnupg2
  UpgradeStatus: No upgrade log present (probably fresh install)

** Summary changed:

- gpg buggy on RISC-V when vector length /= 128B
+ [SRU] gpg buggy on RISC-V when vector length /= 128B

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https://bugs.launchpad.net/bugs/2154120

Title:
  [SRU] gpg buggy on RISC-V when vector length /= 128B

Status in gnupg2 package in Ubuntu:
  Invalid
Status in libgcrypt20 package in Ubuntu:
  Confirmed
Status in gnupg2 source package in Questing:
  Invalid
Status in libgcrypt20 source package in Questing:
  New
Status in gnupg2 source package in Resolute:
  Invalid
Status in libgcrypt20 source package in Resolute:
  Confirmed
Status in gnupg2 source package in Stonking:
  Invalid
Status in libgcrypt20 source package in Stonking:
  Confirmed

Bug description:
  [ Impact ]

  GPG is broken on RISC-V when vector length (VLEN) doesn't equal 128B.

  This has been fixed upstream:
  https://github.com/gpg/libgcrypt/commit/3f684fc6ab3ac98320e245a06b3563ad37ec56f5

  The upload backports the upstream commit as debian patch.

  [ Test Plan ]

  Start a RISC-V VM with QEMU, setting vector length to >128.

  For this, check

  https://documentation.ubuntu.com/hardware-support/boards/how-
  to/ubuntu_supported/qemu-riscv/

  for the full command, and modify it to set vlen:

  qemu-system-riscv64 -cpu max,vlen=256 ...

  Then, in the VM, run the following commands:

  head -c 10000 /dev/urandom > in.bin
  PW="testpw-correct-horse-battery-staple"
  gpg --batch --pinentry-mode loopback --passphrase "$PW" --yes --symmetric \
      --cipher-algo AES256 --output out.gpg in.bin
  gpg --batch --pinentry-mode loopback --passphrase "$PW" --yes \
     --decrypt --output dec.bin out.gpg

  
  This should succeed with only a success message from gpg. However, it currently returns:

  gpg: AES256.CFB encrypted data
  gpg: encrypted with 1 passphrase
  gpg: WARNING: encrypted message has been manipulated!

  It might also be useful to check that basic GPG functionality still
  works.

  [ Where problems could occur ]

  Given that this is a change in a library used by GPG, we need to make
  sure that basic GPG features still work, or that could introduce
  issues around apt and any other GPG user.

  [ Other Info ]

  Original bug report:

  GPG is broken on RISC-V when vector length (VLEN) doesn't equal 128B.

  This has been fixed upstream:
  https://github.com/gpg/libgcrypt/commit/3f684fc6ab3ac98320e245a06b3563ad37ec56f5

  Test:

  head -c 10000 /dev/urandom > in.bin
  PW="testpw-correct-horse-battery-staple"
  gpg --batch --pinentry-mode loopback --passphrase "$PW" --yes --symmetric \
      --cipher-algo AES256 --output out.gpg in.bin
  gpg --batch --pinentry-mode loopback --passphrase "$PW" --yes \
     --decrypt --output dec.bin out.gpg
  if cmp -s in.bin dec.bin; then
    echo "PASS encrypt/decrypt"
  else
    echo "MISMATCH"
  fi

  Run this on x86 it works fine but run it on SpacemiT K3 with VLEN=256
  it fails.

  ProblemType: Bug
  DistroRelease: Ubuntu 26.04
  Package: gpg 2.4.8-4ubuntu3
  Uname: Linux 6.18.3-5-spacemit-generic riscv64
  ApportVersion: 2.34.0-0ubuntu2
  Architecture: riscv64
  CasperMD5CheckResult: unknown
  CloudArchitecture: riscv64
  CloudID: nocloud
  CloudName: unknown
  CloudPlatform: nocloud
  CloudSubPlatform: config-disk (/dev/sda2)
  Date: Sun May 24 10:40:29 2026
  ProcEnviron:
   LANG=C.UTF-8
   PATH=(custom, no user)
   SHELL=/bin/bash
   TERM=tmux-256color
   XDG_RUNTIME_DIR=<set>
  SourcePackage: gnupg2
  UpgradeStatus: No upgrade log present (probably fresh install)

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