path: root/http-backend.c
diff options
authorShawn O. Pearce <>2010-03-22 14:22:04 (GMT)
committerJunio C Hamano <>2010-03-24 21:40:56 (GMT)
commit5856b5f568ba957a0ea094fa676641ab246021fc (patch)
treeef078b3d6bbf301f26f2f3517180eb8dcb145b51 /http-backend.c
parent0b3dcfe721dc8734e2688f936afad055d8541d97 (diff)
http-backend: Don't infinite loop during die()
If stdout has already been closed by the CGI and die() gets called, the CGI will fail to write the "Status: 500 Internal Server Error" to the pipe, which results in die() being called again (via safe_write). This goes on in an infinite loop until the stack overflows and the process is killed by SIGSEGV. Instead set a flag on the first die() invocation and if we came back to the handler, just die silently, as it only means we failed to report the failure---we cannot report anything anyway in such a case. This way failures to write the error messages to the stdout pipe do not result in an infinite loop. We also now report on the death to stderr before we report to stdout, to increase the chances that the cause of the die() invocation will appear in the server's error log. Signed-off-by: Shawn O. Pearce <> Signed-off-by: Junio C Hamano <> fixup! http-backend.c: Don't infinite loop Now die_webcgi() actually can return during a recursive call into it, causing http-backend.c:554: error: 'noreturn' function does return The only reason we would come back to the die handler is because we failed during it, so we cannot report anything anyway. Signed-off-by: Junio C Hamano <>
Diffstat (limited to 'http-backend.c')
1 files changed, 11 insertions, 7 deletions
diff --git a/http-backend.c b/http-backend.c
index 345c12b..d1e83d0 100644
--- a/http-backend.c
+++ b/http-backend.c
@@ -538,15 +538,19 @@ static void service_rpc(char *service_name)
static NORETURN void die_webcgi(const char *err, va_list params)
- char buffer[1000];
+ static int dead;
- http_status(500, "Internal Server Error");
- hdr_nocache();
- end_headers();
+ if (!dead) {
+ char buffer[1000];
+ dead = 1;
- vsnprintf(buffer, sizeof(buffer), err, params);
- fprintf(stderr, "fatal: %s\n", buffer);
- exit(0);
+ vsnprintf(buffer, sizeof(buffer), err, params);
+ fprintf(stderr, "fatal: %s\n", buffer);
+ http_status(500, "Internal Server Error");
+ hdr_nocache();
+ end_headers();
+ }
+ exit(0); /* we successfully reported a failure ;-) */
static char* getdir(void)