What causes "%s: can't read ICC profile from %s " in DrKLO/Telegram?

Use a stable, complete, local copy of the ICC profile and ensure nothing writes to it during encoding.

%s: can't read ICC profile from %s

Error message

%s: can't read ICC profile from %s

What it means

After allocating the ICC buffer, cjpeg reads icc_len bytes with fread(icc_profile, icc_len, 1, icc_file). If fread returns < 1 (read error or premature EOF where fewer than icc_len bytes could be read), it prints this message, frees the buffer, closes the file, and exits EXIT_FAILURE.

Source

Thrown at TMessagesProj/jni/mozjpeg/cjpeg.c:779

  if (icc_filename != NULL) {
    if ((icc_file = fopen(icc_filename, READ_BINARY)) == NULL) {
      fprintf(stderr, "%s: can't open %s\n", progname, icc_filename);
      exit(EXIT_FAILURE);
    }
    if (fseek(icc_file, 0, SEEK_END) < 0 ||
        (icc_len = ftell(icc_file)) < 1 ||
        fseek(icc_file, 0, SEEK_SET) < 0) {
      fprintf(stderr, "%s: can't determine size of %s\n", progname,
              icc_filename);
      exit(EXIT_FAILURE);
    }
    if ((icc_profile = (JOCTET *)malloc(icc_len)) == NULL) {
      fprintf(stderr, "%s: can't allocate memory for ICC profile\n", progname);
      fclose(icc_file);
      exit(EXIT_FAILURE);
    }
    if (fread(icc_profile, icc_len, 1, icc_file) < 1) {
      fprintf(stderr, "%s: can't read ICC profile from %s\n", progname,
              icc_filename);
      free(icc_profile);
      fclose(icc_file);
      exit(EXIT_FAILURE);
    }
    fclose(icc_file);
  }

#ifdef PROGRESS_REPORT
  start_progress_monitor((j_common_ptr)&cinfo, &progress);
#endif

  /* Figure out the input file format, and set up to read it. */
  src_mgr = select_file_type(&cinfo, input_file);
  src_mgr->input_file = input_file;

  /* Read the input file header to obtain file size & colorspace. */
  (*src_mgr->start_input) (&cinfo, src_mgr);

View on GitHub (pinned to 45ab8f4308)

Solutions

Use a stable, complete, local copy of the ICC profile and ensure nothing writes to it during encoding.
Open files in binary mode to avoid translation issues; verify integrity with a checksum (e.g. sha256) before encoding.
If storage is unreliable, copy the profile to local tmp storage first and pass that path.

Example fix

# before: file truncated concurrently / unreliable read
cjpeg -icc /netmount/profile.icc in.ppm out.jpg
# after: copy to stable local path
install -m 0644 /netmount/profile.icc /tmp/profile.icc
cjpeg -icc /tmp/profile.icc in.ppm out.jpg

Defensive patterns

Strategy: validation

Validate before calling

#!/bin/sh
ICC="$1"
# Ensure file is stable and fully readable: copy to local tmp and checksum
TMP="$(mktemp)"; cp -- "$ICC" "$TMP" || { echo 'cannot stage ICC file' >&2; exit 1; }
[ "$(stat -c%s "$TMP")" -ge 1 ] || { echo 'staged ICC empty' >&2; rm -f "$TMP"; exit 1; }
cjpeg -icc "$TMP" in.ppm out.jpg; rc=$?; rm -f "$TMP"; exit $rc

Type guard

// n/a: filesystem integrity check in the caller.

Try / catch

if ! cjpeg -icc "$ICC" in.ppm out.jpg 2>/tmp/e; then
  grep -q "can't read ICC profile" /tmp/e && { echo "ICC read failed (truncated/I/O error): $ICC" >&2; exit 1; }
fi

Prevention

Stage the ICC profile to reliable local storage before encoding.
Verify a checksum (sha256) of the profile to detect truncation/corruption.
Avoid network mounts or concurrent writers on the ICC file during read.

When it happens

Trigger: The file shrank between the ftell size probe and the read (TOCTOU), a read I/O error occurred, or the reported size did not match actual readable bytes (e.g. text-mode translation on some platforms, or a file on an unreliable mount).

Common situations: The file being modified/truncated concurrently; flaky storage (SD card, network mount); platform text-mode CR/LF translation shrinking effective bytes (on systems where READ_BINARY is not truly binary); corrupted download.

Related errors

AI-assisted analysis of DrKLO/Telegram@45ab8f4308 (2026-08-14). Data as JSON: /api/errors/0d8175f4503ce9b5. Report an issue: GitHub.