use HOST_NAME_MAX to size buffers for gethostname(2)
POSIX limits the length of host names to HOST_NAME_MAX. Export the fallback definition from daemon.c and use this constant to make all buffers used with gethostname(2) big enough for any possible result and a terminating NUL. Inspired-by: David Turner <dturner@twosigma.com> Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: David Turner <dturner@twosigma.com> Reviewed-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
René Scharfe committed
Apr 18, 2017 at 17:57 UTC
da25bdb7766c01665500cf7c7b75e76ea1f28b49
6 files changed
+14
-10
builtin/gc.c
+7
-3
@@ -220,7 +220,7 @@ static int need_to_gc(void)
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static const char *lock_repo_for_gc(int force, pid_t* ret_pid)
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{
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static struct lock_file lock;
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- char my_host[128];
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+ char my_host[HOST_NAME_MAX + 1];
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struct strbuf sb = STRBUF_INIT;
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struct stat st;
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uintmax_t pid;
@@ -239,8 +239,12 @@ static const char *lock_repo_for_gc(int force, pid_t* ret_pid)
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fd = hold_lock_file_for_update(&lock, pidfile_path,
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LOCK_DIE_ON_ERROR);
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if (!force) {
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- static char locking_host[128];
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+ static char locking_host[HOST_NAME_MAX + 1];
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+ static char *scan_fmt;
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int should_exit;
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+
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+ if (!scan_fmt)
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+ scan_fmt = xstrfmt("%s %%%dc", "%"SCNuMAX, HOST_NAME_MAX);
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fp = fopen(pidfile_path, "r");
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memset(locking_host, 0, sizeof(locking_host));
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should_exit =
@@ -256,7 +260,7 @@ static const char *lock_repo_for_gc(int force, pid_t* ret_pid)
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* running.
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*/
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time(NULL) - st.st_mtime <= 12 * 3600 &&
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- fscanf(fp, "%"SCNuMAX" %127c", &pid, locking_host) == 2 &&
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+ fscanf(fp, scan_fmt, &pid, locking_host) == 2 &&
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/* be gentle to concurrent "gc" on remote hosts */
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(strcmp(locking_host, my_host) || !kill(pid, 0) || errno == EPERM);
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if (fp != NULL)
builtin/receive-pack.c
+1
-1
@@ -1655,7 +1655,7 @@ static const char *unpack(int err_fd, struct shallow_info *si)
1655
if (status)
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return "unpack-objects abnormal exit";
1657
} else {
1658
- char hostname[256];
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+ char hostname[HOST_NAME_MAX + 1];
1659
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argv_array_pushl(&child.args, "index-pack",
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"--stdin", hdr_arg, NULL);
daemon.c
-4
@@ -4,10 +4,6 @@
4
#include "strbuf.h"
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#include "string-list.h"
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-#ifndef HOST_NAME_MAX
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-#define HOST_NAME_MAX 256
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-#endif
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-
7
#ifdef NO_INITGROUPS
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#define initgroups(x, y) (0) /* nothing */
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#endif
fetch-pack.c
+1
-1
@@ -745,7 +745,7 @@ static int get_pack(struct fetch_pack_args *args,
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if (args->use_thin_pack)
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argv_array_push(&cmd.args, "--fix-thin");
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if (args->lock_pack || unpack_limit) {
748
- char hostname[256];
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+ char hostname[HOST_NAME_MAX + 1];
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if (gethostname(hostname, sizeof(hostname)))
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xsnprintf(hostname, sizeof(hostname), "localhost");
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argv_array_pushf(&cmd.args,
git-compat-util.h
+4
@@ -878,6 +878,10 @@ static inline size_t xsize_t(off_t len)
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__attribute__((format (printf, 3, 4)))
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extern int xsnprintf(char *dst, size_t max, const char *fmt, ...);
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+#ifndef HOST_NAME_MAX
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+#define HOST_NAME_MAX 256
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+#endif
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+
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/* in ctype.c, for kwset users */
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extern const unsigned char tolower_trans_tbl[256];
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ident.c
+1
-1
@@ -120,7 +120,7 @@ static int canonical_name(const char *host, struct strbuf *out)
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static void add_domainname(struct strbuf *out, int *is_bogus)
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{
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- char buf[1024];
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+ char buf[HOST_NAME_MAX + 1];
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if (gethostname(buf, sizeof(buf))) {
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warning_errno("cannot get host name");