ci: cancel stuck runs; cap ASan wall time; silence path snprintf warning

The sanitizers job wedged the only runner by printing AddressSanitizer
DEADLYSIGNAL forever (Docker without SYS_PTRACE). Concurrency now cancels
in-progress jobs on a new push, and make asan is wrapped in timeout -s KILL
480 with shallow ASAN_OPTIONS.

Also copy the path with memcpy after the length check so -O1 asan builds
do not warn about snprintf truncation into OS_PATH_MAX.

.gitea/workflows/ci.yml

@@ -4,9 +4,16 @@ on:
   push:
   pull_request:
 
+# One runner: cancel the previous push's jobs (avoids a stuck ASan job
+# blocking every later commit).
+concurrency:
+  group: ci-${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
   linux:
     runs-on: ubuntu-latest
+    timeout-minutes: 30
     strategy:
       fail-fast: false
       matrix:
@@ -38,6 +45,7 @@ jobs:
 
   sanitizers:
     runs-on: ubuntu-latest
+    timeout-minutes: 15
     steps:
       - uses: actions/checkout@v4
       - name: Install dependencies
@@ -48,10 +56,22 @@ jobs:
           $SUDO apt-get install -y --no-install-recommends \
             build-essential pkg-config libcurl4-openssl-dev libncurses-dev
       - name: ASan + UBSan
-        run: make asan
+        timeout-minutes: 10
+        env:
+          # Docker runners without SYS_PTRACE can spin forever on
+          # AddressSanitizer:DEADLYSIGNAL; keep the handler shallow and
+          # hard-cap wall time so the single runner is not wedged.
+          ASAN_OPTIONS: abort_on_error=1:halt_on_error=1:detect_leaks=0:use_sigaltstack=0
+          UBSAN_OPTIONS: halt_on_error=1:print_stacktrace=1
+        run: |
+          if ! timeout -s KILL 480 make asan; then
+            echo "::error::make asan failed or timed out after 8m (if the log is only DEADLYSIGNAL, give the runner SYS_PTRACE / seccomp=unconfined)"
+            exit 1
+          fi
 
   musl:
     runs-on: ubuntu-latest
+    timeout-minutes: 30
     container: alpine:3.20
     steps:
       - name: Install dependencies
@@ -71,6 +91,7 @@ jobs:
   macos:
     if: ${{ vars.HAVE_MACOS_RUNNER == 'true' }}
     runs-on: macos-latest
+    timeout-minutes: 30
     steps:
       - uses: actions/checkout@v4
       - name: Install dependencies

src/sandbox_exec.c

@@ -566,9 +566,10 @@ static void sc_rewrite(int pid, const char *in, char *out, size_t n) {
 static int sc_abs_ok(const sc_state_t *s, const char *full, int follow,
                      int strict) {
   char path[OS_PATH_MAX], real[OS_PATH_MAX], loc[2 * OS_PATH_MAX + 2];
-  if (strlen(full) >= sizeof(path))
+  size_t flen = strlen(full);
+  if (flen >= sizeof(path))
     return 0;
-  snprintf(path, sizeof(path), "%s", full);
+  memcpy(path, full, flen + 1);
   size_t n = strlen(path);
   while (n > 1 && path[n - 1] == '/')
     path[--n] = 0;