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cargo clean: Add target directory validation #16712

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81680d9
add tests showing cargo clean does not validate target dir
TanmayArya-1p Mar 21, 2026
ac8856a
cargo clean: add target dir validation
TanmayArya-1p Mar 21, 2026
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1 change: 1 addition & 0 deletions src/bin/cargo/commands/clean.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -163,6 +163,7 @@ pub fn exec(gctx: &mut GlobalContext, args: &ArgMatches) -> CliResult {
profile_specified: args.contains_id("profile") || args.flag("release"),
doc: args.flag("doc"),
dry_run: args.dry_run(),
explicit_target_dir_arg: args.contains_id("target-dir"),
};
ops::clean(&ws, &opts)?;
Ok(())
Expand Down
52 changes: 51 additions & 1 deletion src/cargo/ops/cargo_clean.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -13,9 +13,10 @@ use cargo_util::paths;
use indexmap::{IndexMap, IndexSet};

use std::ffi::OsString;
use std::fs;
use std::io::Read;
use std::path::{Path, PathBuf};
use std::rc::Rc;
use std::{fs, io};

pub struct CleanOptions<'gctx> {
pub gctx: &'gctx GlobalContext,
Expand All @@ -31,6 +32,8 @@ pub struct CleanOptions<'gctx> {
pub doc: bool,
/// If set, doesn't delete anything.
pub dry_run: bool,
/// true if target-dir was was explicitly specified via --target-dir
pub explicit_target_dir_arg: bool,
}

pub struct CleanContext<'gctx> {
Expand Down Expand Up @@ -66,6 +69,22 @@ pub fn clean(ws: &Workspace<'_>, opts: &CleanOptions<'_>) -> CargoResult<()> {
}
}

// do some validation on target_dir if it was specified via --target-dir
if opts.explicit_target_dir_arg {
let target_dir_path = target_dir.as_path_unlocked();

// check if the target directory has a valid CACHEDIR.TAG
if let Err(err) = validate_target_dir_tag(target_dir_path) {
// if target_dir was passed explicitly via --target-dir, then hard error if validation fails
let title = format!("cannot clean `{}`: {err}", target_dir_path.display());
let report = [Level::ERROR
.primary_title(title)
.element(Level::NOTE.message(CLEAN_ABORT_NOTE))];
gctx.shell().print_report(&report, false)?;
return Err(crate::AlreadyPrintedError::new(anyhow::anyhow!("")).into());
}
}

if opts.doc {
if !opts.spec.is_empty() {
// FIXME: https://github.com/rust-lang/cargo/issues/8790
Expand Down Expand Up @@ -122,6 +141,37 @@ pub fn clean(ws: &Workspace<'_>, opts: &CleanOptions<'_>) -> CargoResult<()> {
Ok(())
}

fn validate_target_dir_tag(target_dir_path: &Path) -> CargoResult<()> {
const TAG_SIGNATURE: &[u8] = b"Signature: 8a477f597d28d172789f06886806bc55";

let tag_path = target_dir_path.join("CACHEDIR.TAG");

// per https://bford.info/cachedir the tag file must not be a symlink
if tag_path.is_symlink() {
bail!("expect `CACHEDIR.TAG` to be a regular file, got a symlink");
}

if !tag_path.is_file() {
bail!("missing or invalid `CACHEDIR.TAG` file");
}

let mut file = fs::File::open(&tag_path)
.map_err(|err| anyhow::anyhow!("failed to open `{}`: {}", tag_path.display(), err))?;

let mut buf = [0u8; TAG_SIGNATURE.len()];
match file.read_exact(&mut buf) {
Ok(()) if &buf[..] == TAG_SIGNATURE => {}
Err(e) if e.kind() != io::ErrorKind::UnexpectedEof => {
bail!("failed to read `{}`: {e}", tag_path.display());
}
_ => {
bail!("invalid signature in `CACHEDIR.TAG` file");
}
}

Ok(())
}

fn clean_specs(
clean_ctx: &mut CleanContext<'_>,
ws: &Workspace<'_>,
Expand Down
239 changes: 239 additions & 0 deletions tests/testsuite/clean.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -1208,3 +1208,242 @@ fn target_dir_is_symlink_file() {
// make sure cargo has not deleted the file of the symlinked target dir
assert!(p.root().join("bar-dest").exists());
}

#[cargo_test]
fn explicit_target_dir_tag_not_present() {
// invalid target dir explicitly specified via --target-dir cli arg

let p = project()
.file("Cargo.toml", &basic_bin_manifest("foo"))
.file("src/foo.rs", &main_file(r#""i am foo""#, &[]))
.file("bar/.keep", "")
.build();

p.cargo("clean --target-dir bar")
.with_stdout_data("")
.with_stderr_data(str![[r#"
[ERROR] cannot clean `[ROOT]/foo/bar`: missing or invalid `CACHEDIR.TAG` file
|
= [NOTE] cleaning has been aborted to prevent accidental deletion of unrelated files

"#]])
.with_status(101)
.run();
}

#[cargo_test]
fn explicit_target_dir_tag_invalid_signature() {
let p = project()
.file("Cargo.toml", &basic_bin_manifest("foo"))
.file("src/foo.rs", &main_file(r#""i am foo""#, &[]))
.file("bar/CACHEDIR.TAG", "Signature: 1234")
.build();

p.cargo("clean --target-dir bar")
.with_stdout_data("")
.with_stderr_data(str![[r#"
[ERROR] cannot clean `[ROOT]/foo/bar`: invalid signature in `CACHEDIR.TAG` file
|
= [NOTE] cleaning has been aborted to prevent accidental deletion of unrelated files

"#]])
.with_status(101)
.run();
}

#[cargo_test]
fn explicit_target_dir_tag_symlink() {
let p = project()
.file("Cargo.toml", &basic_bin_manifest("foo"))
.file("src/foo.rs", &main_file(r#""i am foo""#, &[]))
.file(
"src/CACHEDIR.TAG",
"Signature: 8a477f597d28d172789f06886806bc55",
)
.symlink("src/CACHEDIR.TAG", "bar/CACHEDIR.TAG")
.build();

p.cargo("clean --target-dir bar")
.with_stdout_data("")
.with_stderr_data(str![[r#"
[ERROR] cannot clean `[ROOT]/foo/bar`: expect `CACHEDIR.TAG` to be a regular file, got a symlink
|
= [NOTE] cleaning has been aborted to prevent accidental deletion of unrelated files

"#]])
.with_status(101)
.run();
}

#[cargo_test]
fn explicit_target_dir_tag_valid() {
let p = project()
.file("Cargo.toml", &basic_bin_manifest("foo"))
.file("src/foo.rs", &main_file(r#""i am foo""#, &[]))
.file(
"bar/CACHEDIR.TAG",
"Signature: 8a477f597d28d172789f06886806bc55",
)
.build();

p.cargo("clean --target-dir bar").run();
}

#[cargo_test]
fn env_target_dir_tag_not_present() {
// invalid target dir specified via env var

let p = project()
.file("Cargo.toml", &basic_bin_manifest("foo"))
.file("bar/.keep", "")
.file("src/foo.rs", &main_file(r#""i am foo""#, &[]))
.build();

p.cargo("clean")
.env("CARGO_TARGET_DIR", "bar")
.with_stderr_data(str![[r#"
[REMOVED] [FILE_NUM] files, [FILE_SIZE]B total

"#]])
.run();
}

#[cargo_test]
fn env_target_dir_tag_invalid_signature() {
let p = project()
.file("Cargo.toml", &basic_bin_manifest("foo"))
.file("src/foo.rs", &main_file(r#""i am foo""#, &[]))
.file("bar/CACHEDIR.TAG", "Signature: 1234")
.build();

p.cargo("clean")
.env("CARGO_TARGET_DIR", "bar")
.with_stderr_data(str![[r#"
[REMOVED] [FILE_NUM] files, [FILE_SIZE]B total

"#]])
.run();
}

#[cargo_test]
fn env_target_dir_tag_symlink() {
let p = project()
.file("Cargo.toml", &basic_bin_manifest("foo"))
.file("src/foo.rs", &main_file(r#""i am foo""#, &[]))
.file(
"src/CACHEDIR.TAG",
"Signature: 8a477f597d28d172789f06886806bc55",
)
.symlink("src/CACHEDIR.TAG", "bar/CACHEDIR.TAG")
.build();

p.cargo("clean")
.env("CARGO_TARGET_DIR", "bar")
.with_stderr_data(str![[r#"
[REMOVED] [FILE_NUM] files, [FILE_SIZE]B total

"#]])
.run();
}

#[cargo_test]
fn env_target_dir_tag_valid() {
let p = project()
.file("Cargo.toml", &basic_bin_manifest("foo"))
.file("src/foo.rs", &main_file(r#""i am foo""#, &[]))
.file(
"bar/CACHEDIR.TAG",
"Signature: 8a477f597d28d172789f06886806bc55",
)
.build();

p.cargo("clean").env("CARGO_TARGET_DIR", "bar").run();
}

#[cargo_test]
fn config_target_dir_tag_not_present() {
// invalid target dir specified via build config

let p = project()
.file("Cargo.toml", &basic_bin_manifest("foo"))
.file("bar/.keep", "")
.file("src/foo.rs", "")
.file(
".cargo/config.toml",
"[build]
target-dir = 'bar'",
)
.build();

p.cargo("clean")
.with_stderr_data(str![[r#"
[REMOVED] [FILE_NUM] files, [FILE_SIZE]B total

"#]])
.run();
}

#[cargo_test]
fn config_target_dir_tag_invalid_signature() {
let p = project()
.file("Cargo.toml", &basic_bin_manifest("foo"))
.file("src/foo.rs", &main_file(r#""i am foo""#, &[]))
.file("bar/CACHEDIR.TAG", "Signature: 1234")
.file(
".cargo/config.toml",
"[build]
target-dir = 'bar'",
)
.build();

p.cargo("clean")
.with_stderr_data(str![[r#"
[REMOVED] [FILE_NUM] files, [FILE_SIZE]B total

"#]])
.run();
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@weihanglo weihanglo Mar 27, 2026

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nit: This formatting change should be in the first commit

}

#[cargo_test]
fn config_target_dir_tag_symlink() {
let p = project()
.file("Cargo.toml", &basic_bin_manifest("foo"))
.file("src/foo.rs", &main_file(r#""i am foo""#, &[]))
.file(
"src/CACHEDIR.TAG",
"Signature: 8a477f597d28d172789f06886806bc55",
)
.symlink("src/CACHEDIR.TAG", "bar/CACHEDIR.TAG")
.file(
".cargo/config.toml",
"[build]
target-dir = 'bar'",
)
.build();

p.cargo("clean")
.with_stderr_data(str![[r#"
[REMOVED] [FILE_NUM] files, [FILE_SIZE]B total

"#]])
.run();
}

#[cargo_test]
fn config_target_dir_tag_valid() {
let p = project()
.file("Cargo.toml", &basic_bin_manifest("foo"))
.file("src/foo.rs", &main_file(r#""i am foo""#, &[]))
.file(
"bar/CACHEDIR.TAG",
"Signature: 8a477f597d28d172789f06886806bc55",
)
.file(
".cargo/config.toml",
"[build]
target-dir = 'bar'",
)
.build();

p.cargo("clean").run();
}