Library panics with 'misaligned pointer dereference' error

[dhruvkb]

When I try a simple program to get the info for group 5, 'operator' on macOS, the program panics with 'misaligned pointer dereference: address must be a multiple of 0x8 but is 0x14480860b'

use users:{get_group_by_gid};

fn main() {
	let group = get_group_by_gid(5).unwrap();
	println!("{:?}", group.name());
}

thread 'main' panicked at 'misaligned pointer dereference: address must be a multiple of 0x8 but is 0x14480860b', /Users/dhruvkb/.cargo/registry/src/index.crates.io-6f17d22bba15001f/users-0.11.0/src/base.rs:297:34
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
thread 'main' panicked at 'panic in a function that cannot unwind', library/core/src/panicking.rs:126:5
stack backtrace:
   0:        0x10490ae70 - std::backtrace_rs::backtrace::libunwind::trace::h0a647ce7e8dc2fab
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/../../backtrace/src/backtrace/libunwind.rs:93:5
   1:        0x10490ae70 - std::backtrace_rs::backtrace::trace_unsynchronized::hea920694a2a8ac80
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:        0x10490ae70 - std::sys_common::backtrace::_print_fmt::h7b4e20c1da2ebb61
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/sys_common/backtrace.rs:65:5
   3:        0x10490ae70 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h819e9cbdf1a9e730
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/sys_common/backtrace.rs:44:22
   4:        0x1049227c8 - core::fmt::write::ha5e9bf3131ecb7c0
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/core/src/fmt/mod.rs:1254:17
   5:        0x1049086f0 - std::io::Write::write_fmt::h414ce9994bf17404
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/io/mod.rs:1698:15
   6:        0x10490ac84 - std::sys_common::backtrace::_print::h28d98f2094da6d1d
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/sys_common/backtrace.rs:47:5
   7:        0x10490ac84 - std::sys_common::backtrace::print::h8072db0bbd5bcc3d
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/sys_common/backtrace.rs:34:9
   8:        0x10490c1a4 - std::panicking::default_hook::{{closure}}::h2c85c5b0c2ede151
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/panicking.rs:269:22
   9:        0x10490bf64 - std::panicking::default_hook::hcf2f70992d02f6fe
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/panicking.rs:288:9
  10:        0x10490c67c - std::panicking::rust_panic_with_hook::h023af7f90b47eb8b
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/panicking.rs:691:13
  11:        0x10490c570 - std::panicking::begin_panic_handler::{{closure}}::h14283519edc1d634
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/panicking.rs:580:13
  12:        0x10490b290 - std::sys_common::backtrace::__rust_end_short_backtrace::hc366c0b0cef5b747
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/sys_common/backtrace.rs:150:18
  13:        0x10490c344 - rust_begin_unwind
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/panicking.rs:578:5
  14:        0x1049350b4 - core::panicking::panic_nounwind_fmt::h48fca0782e5a5b33
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/core/src/panicking.rs:96:14
  15:        0x104935130 - core::panicking::panic_nounwind::hc8dbc36c10163a33
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/core/src/panicking.rs:126:5
  16:        0x104935228 - core::panicking::panic_cannot_unwind::h8bbe98643cda7e5c
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/core/src/panicking.rs:188:5
  17:        0x1046231c4 - users::base::members::h4b04c104b03b5dc7
                               at /Users/dhruvkb/.cargo/registry/src/index.crates.io-6f17d22bba15001f/users-0.11.0/src/base.rs:291:1
  18:        0x104620db8 - users::base::os::unix::GroupExtras::from_struct::hd0996ceb72aaa79f
                               at /Users/dhruvkb/.cargo/registry/src/index.crates.io-6f17d22bba15001f/users-0.11.0/src/base.rs:1060:33
  19:        0x104622fb4 - users::base::struct_to_group::h51af19c287452270
                               at /Users/dhruvkb/.cargo/registry/src/index.crates.io-6f17d22bba15001f/users-0.11.0/src/base.rs:280:19
  20:        0x104623900 - users::base::get_group_by_gid::ha8a8b2a2c9e631bd
                               at /Users/dhruvkb/.cargo/registry/src/index.crates.io-6f17d22bba15001f/users-0.11.0/src/base.rs:473:26
  21:        0x104629970 - <users::cache::UsersCache as users::traits::Groups>::get_group_by_gid::h0734a478540ff270
                               at /Users/dhruvkb/.cargo/registry/src/index.crates.io-6f17d22bba15001f/users-0.11.0/src/cache.rs:291:30
  22:        0x1045e6dfc - <pls::models::owner::OwnerMan as core::default::Default>::default::hac1e2e76a342f1bc
                               at /Users/dhruvkb/Developer/personal/mega/pls/src/models/owner.rs:36:15
  23:        0x10459d5a0 - pls::models::pls::Pls::list::h7380d37d48293584
                               at /Users/dhruvkb/Developer/personal/mega/pls/src/models/pls.rs:54:23
  24:        0x10459d908 - pls::models::pls::Pls::run::h9d3a92469cd4f4f4
                               at /Users/dhruvkb/Developer/personal/mega/pls/src/models/pls.rs:89:7
  25:        0x10459cf40 - pls::main::h5e2c7abac9dc06f0
                               at /Users/dhruvkb/Developer/personal/mega/pls/src/main.rs:15:2
  26:        0x1045a8764 - core::ops::function::FnOnce::call_once::h4b0e21d5f464699e
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/core/src/ops/function.rs:250:5
  27:        0x1045de2a0 - std::sys_common::backtrace::__rust_begin_short_backtrace::hb682b34e30f3de1d
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/sys_common/backtrace.rs:134:18
  28:        0x1045e8450 - std::rt::lang_start::{{closure}}::h7628ef326ae876a7
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/rt.rs:166:18
  29:        0x104904d04 - core::ops::function::impls::<impl core::ops::function::FnOnce<A> for &F>::call_once::h6f7eb9f266759f90
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/core/src/ops/function.rs:287:13
  30:        0x104904d04 - std::panicking::try::do_call::h54b2febb9ea02379
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/panicking.rs:485:40
  31:        0x104904d04 - std::panicking::try::h95a2f9f45aeb75ea
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/panicking.rs:449:19
  32:        0x104904d04 - std::panic::catch_unwind::h9686256fa0fc97a1
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/panic.rs:140:14
  33:        0x104904d04 - std::rt::lang_start_internal::{{closure}}::h227e8b10bc4e486b
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/rt.rs:148:48
  34:        0x104904d04 - std::panicking::try::do_call::h414d500a3ee5fa44
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/panicking.rs:485:40
  35:        0x104904d04 - std::panicking::try::h4f025820961f1c3f
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/panicking.rs:449:19
  36:        0x104904d04 - std::panic::catch_unwind::h0b71dfe3538d125d
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/panic.rs:140:14
  37:        0x104904d04 - std::rt::lang_start_internal::h8ee16b8f6c950a26
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/rt.rs:148:20
  38:        0x1045e841c - std::rt::lang_start::had4655a8be1c3515
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/rt.rs:165:17
  39:        0x10459cfa8 - _main
thread caused non-unwinding panic. aborting.

[dhruvkb]

I know exa uses the library so I cloned it, added the same two lines to its main() function and it works there!

[dhruvkb]

Solved on StackOverflow. Available at fork https://github.com/dhruvkb/rust-users.

[carnil]

The proposed patch seems to be dhruvkb@e6ba8a8

This is https://rustsec.org/advisories/RUSTSEC-2023-0059.html