Segmentation fault when writing encrypted database with vendored SQLCipher and OpenSSL on OpenBSD

[link2xt]

I have minimized segfault to this:

use std::error::Error;
use std::fs;

use rusqlite::{Connection, OpenFlags};

fn main() -> Result<(), Box<dyn Error>> {
    fs::remove_file("foobar.db").ok();
    let conn = Connection::open_with_flags(
        "foobar.db",
        OpenFlags::SQLITE_OPEN_READ_WRITE | OpenFlags::SQLITE_OPEN_CREATE,
    )?;
    conn.pragma_update(None, "key", "foobar")?;
    conn.execute("CREATE TABLE foo (bar INTEGER)", ())?;

    Ok(())
}

Corresponding Cargo.toml:

[package]
name = "minimalsegfault"
version = "0.1.0"
edition = "2021"

# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

[dependencies]
rusqlite = { version = "0.31.0", features = ["sqlcipher", "bundled-sqlcipher-vendored-openssl"] }

It does not segfault if bundled-sqlcipher-vendored-openssl feature is removed or replaced with bundled-sqlcipher.

It also does not segfault if I run it under lldb, and then does not segfault if I run it directly as target/debug/minimalsegfault, but starts segfaulting again if I remove target/debug/minimalsegfault and rebuild it:

deltachat$ sha256 target/debug/minmalsegfault
SHA256 (target/debug/minmalsegfault) = 473a948649749621cddd7dc27316323b6e99d9019de079bfaecb5c72b633ac41
deltachat$ target/debug/minmalsegfault
Segmentation fault (core dumped)
deltachat$ lldb target/debug/minmalsegfault
(lldb) target create "target/debug/minmalsegfault"
Current executable set to '/home/user/link2xt/minmalsegfault/target/debug/minmalsegfault' (x86_64).
(lldb) r
Process 81083 launched: '/home/user/link2xt/minmalsegfault/target/debug/minmalsegfault' (x86_64)
Process 81083 exited with status = 0 (0x00000000)
(lldb) ^D
deltachat$ target/debug/minmalsegfault
deltachat$ target/debug/minmalsegfault
deltachat$ rm target/debug/minmalsegfault
deltachat$ cargo build
    Finished dev [unoptimized + debuginfo] target(s) in 0.37s
deltachat$ sha256 target/debug/minmalsegfault
SHA256 (target/debug/minmalsegfault) = 473a948649749621cddd7dc27316323b6e99d9019de079bfaecb5c72b633ac41
deltachat$ target/debug/minmalsegfault
Segmentation fault (core dumped)

Backtrace from gdb:

(gdb) r
Starting program: /home/user/link2xt/minmalsegfault/target/debug/minmalsegfault
Error while reading shared library symbols:
Dwarf Error: wrong version in compilation unit header (is 4, should be 2) [in module /usr/libexec/ld.so]

Program received signal SIGSEGV, Segmentation fault.
aesni_set_encrypt_key () at crypto/aes/aesni-x86_64.s:4326
4326	crypto/aes/aesni-x86_64.s: No such file or directory.
	in crypto/aes/aesni-x86_64.s
Current language:  auto; currently asm
(gdb) bt
#0  aesni_set_encrypt_key () at crypto/aes/aesni-x86_64.s:4326
#1  0x00000a2ed092b5ad in cipher_hw_aesni_initkey (dat=Variable "dat" is not available.
) at cipher_aes_hw_aesni.inc:37
#2  0x00000a2ed098af48 in cipher_generic_init_internal (ctx=Variable "ctx" is not available.
) at providers/implementations/ciphers/ciphercommon.c:221
#3  0x00000a2ed098ae12 in ossl_cipher_generic_einit (vctx=Variable "vctx" is not available.
) at providers/implementations/ciphers/ciphercommon.c:232
#4  0x00000a2ed07234b1 in evp_cipher_init_internal (ctx=Variable "ctx" is not available.
) at refcount.h:52
#5  0x00000a2ed0723613 in EVP_CipherInit_ex (ctx=Variable "ctx" is not available.
) at crypto/evp/evp_enc.c:462
#6  0x00000a2ed097685f in drbg_ctr_set_ctx_params_locked (vctx=Variable "vctx" is not available.
) at providers/implementations/rands/drbg_ctr.c:603
#7  0x00000a2ed09744b0 in drbg_ctr_instantiate_wrapper (vdrbg=Variable "vdrbg" is not available.
) at providers/implementations/rands/drbg_ctr.c:341
#8  0x00000a2ed082b774 in EVP_RAND_instantiate (ctx=Variable "ctx" is not available.
) at crypto/evp/evp_rand.c:517
#9  0x00000a2ed082ce8b in rand_new_drbg (libctx=Variable "libctx" is not available.
) at crypto/rand/rand_lib.c:687
#10 0x00000a2ed082c0c1 in RAND_get0_primary (ctx=Variable "ctx" is not available.
) at crypto/rand/rand_lib.c:734
#11 0x00000a2ed082c563 in RAND_get0_public (ctx=Variable "ctx" is not available.
) at crypto/rand/rand_lib.c:765
#12 0x00000a2ed082c484 in RAND_bytes_ex (ctx=Variable "ctx" is not available.
) at crypto/rand/rand_lib.c:378
#13 0x00000a2ed05bfa9f in sqlcipher_openssl_random (ctx=0x0, buffer=0xa31b1fd8748, length=16) at sqlcipher/sqlite3.c:110178
#14 0x00000a2ed05bdbf9 in sqlcipher_codec_ctx_init_kdf_salt (ctx=0xa31b1fe1328) at sqlcipher/sqlite3.c:108411
#15 0x00000a2ed05be679 in sqlcipher_cipher_ctx_key_derive (ctx=0xa31b1fe1328, c_ctx=0xa31b1fcee78) at sqlcipher/sqlite3.c:108790
#16 0x00000a2ed05be4af in sqlcipher_codec_key_derive (ctx=0xa31b1fe1328) at sqlcipher/sqlite3.c:108860
#17 0x00000a2ed05ba54a in sqlite3Codec (iCtx=0xa31b1fe1328, data=0xa3170ca4008, pgno=1, mode=6) at sqlcipher/sqlite3.c:107084
#18 0x00000a2ed05de20b in pager_write_pagelist (pPager=0xa31b1fcda88, pList=0xa3170ca5040) at sqlcipher/sqlite3.c:61135
#19 0x00000a2ed05ab989 in sqlite3PagerCommitPhaseOne (pPager=0xa31b1fcda88, zSuper=0x0, noSync=0) at sqlcipher/sqlite3.c:63319
#20 0x00000a2ed05abdfa in sqlite3BtreeCommitPhaseOne (p=0xa31b1fdf008, zSuperJrnl=0x0) at sqlcipher/sqlite3.c:74361
#21 0x00000a2ed05ecf79 in vdbeCommit (db=0xa31b1ff6388, p=0xa31b1fde508) at sqlcipher/sqlite3.c:87333
#22 0x00000a2ed05ec29e in sqlite3VdbeHalt (p=0xa31b1fde508) at sqlcipher/sqlite3.c:87743
#23 0x00000a2ed05f36a2 in sqlite3VdbeExec (p=0xa31b1fde508) at sqlcipher/sqlite3.c:93895
#24 0x00000a2ed05af4f1 in sqlite3Step (p=0xa31b1fde508) at sqlcipher/sqlite3.c:90705
#25 0x00000a2ed05a8ee8 in sqlite3_step (pStmt=0xa31b1fde508) at sqlcipher/sqlite3.c:90766
#26 0x00000a2ed058a52a in _ZN8rusqlite13raw_statement12RawStatement4step17h1cc4ee59cbbf8421E (self=0x79b39c47bf40) at raw_statement.rs:106
#27 0x00000a2ed058b477 in _ZN8rusqlite9statement9Statement29execute_with_bound_parameters17ha94539f0bfccc097E (self=0x79b39c47bf38) at statement.rs:659
#28 0x00000a2ed058bd63 in _ZN8rusqlite9statement9Statement7execute17h37b2ea6d243471b8E (self=0x79b39c47bf38, params=0) at statement.rs:113
#29 0x00000a2ed058c960 in _ZN8rusqlite10Connection7execute28_$u7b$$u7b$closure$u7d$$u7d$28_$u7b$$u7b$closure$u7d$$u7d$17h95289cb346774e2aE () at lib.rs:622
#30 0x00000a2ed058b91c in _ZN4core6result19Result$LT$T$C$E$GT$8and_then17h156c923f2b70eba2E (self=Variable "self" is not available.
) at result.rs:1316
#31 0x00000a2ed058c8ec in _ZN8rusqlite10Connection7execute28_$u7b$$u7b$closure$u7d$$u7d$17h11bc1bbdb057931cE (stmt=Variable "stmt" is not available.
) at lib.rs:622
#32 0x00000a2ed058b9e7 in _ZN4core6result19Result$LT$T$C$E$GT$8and_then17h9c31c7498f85d62bE (self=Variable "self" is not available.
) at result.rs:1316
#33 0x00000a2ed058c85a in _ZN8rusqlite10Connection7execute17h911cbc4321d9f801E (self=0x79b39c47c0d0, sql=
      {data_ptr = 0xa2ed04acd7f "CREATE TABLE foo (bar INTEGER)src/main.rsdescription() is deprecated; use Display�r", length = 30}, params=0) at lib.rs:621
#34 0x00000a2ed058a855 in _ZN14minmalsegfault4main17haa5db2fd92e500efE () at main.rs:14
#35 0x00000a2ed058aeb2 in _ZN4core3ops8function6FnOnce9call_once17hb96fff8ad01e0288E () at function.rs:250
#36 0x00000a2ed058c485 in _ZN3std10sys_common9backtrace28__rust_begin_short_backtrace17hd166fc0a34471332E (f=0xa2ed058a600 <_ZN14minmalsegfault4main17haa5db2fd92e500efE>)
    at backtrace.rs:155
#37 0x00000a2ed058ab18 in _ZN3std2rt10lang_start28_$u7b$$u7b$closure$u7d$$u7d$17hac38d9a6d186d8e8E () at rt.rs:166
#38 0x00000a2ed09abe29 in std::rt::lang_start_internal::hf9bc85ac22917681 () from /home/user/link2xt/minmalsegfault/target/debug/minmalsegfault
#39 0x00000a2ed058aaec in _ZN3std2rt10lang_start17hb8161abf303dc758E (main=0xa2ed058a600 <_ZN14minmalsegfault4main17haa5db2fd92e500efE>, argc=1, argv=0x79b39c47c698, sigpipe=0 '\0')
    at rt.rs:165
#40 0x00000a2ed058a9f5 in main () at function.rs:249

I first thought that the problem is a NULL pointer dereference here:

#13 0x00000a2ed05bfa9f in sqlcipher_openssl_random (ctx=0x0, buffer=0xa31b1fd8748, length=16) at sqlcipher/sqlite3.c:110178
#14 0x00000a2ed05bdbf9 in sqlcipher_codec_ctx_init_kdf_salt (ctx=0xa31b1fe1328) at sqlcipher/sqlite3.c:108411

In sqlcipher_codec_ctx_init_kdf_salt the code looks like this around line 108411:

    if(ctx->provider->random(ctx->provider_ctx, ctx->kdf_salt, ctx->kdf_salt_sz) != SQLITE_OK) {

Then in the backtrace we see that sqlcipher_openssl_random is called with ctx=0x0 as the first argument, so apparently ctx->provider_ctx is NULL. But I have looked into SQLCipher code and it seems in case OpenSSL is used as a backend this is intended that provider_ctx is NULL, it is not used anywhere and OpenSSL is initialized globally.

I am running in a VM with OpenBSD current:

$ uname -msrv
OpenBSD 7.5 GENERIC.MP#59 amd64
$ rustc --version
rustc 1.77.2 (25ef9e3d8 2024-04-09) (built from a source tarball)
$ cargo --version
cargo 1.77.2

Minimal example with a lockfile, segfaulting when you run cargo run:
minimalsegfault.tar.gz

The bug is also reproducible with the latest version of rusqlite repo, commit 6218aa4.