From 3fcd52706b6818e785a104ed6c4f2b46e5d1ab2f Mon Sep 17 00:00:00 2001

From: Karel Zak <kzak@redhat.com>

Date: Fri, 12 Jan 2018 11:01:26 +0100

Subject: [PATCH] include/debug: don't print pointer address for SUID programs

* introduce new flag __UL_DEBUG_FL_NOADDR to suppress pointer address printing

  (and MNT_DEBUG_FL_NOADDR for libmount)

* use __UL_DEBUG_FL_NOADDR when SUID

* move ul_debugobj() to debugobj.h, and require UL_DEBUG_CURRENT_MASK

  to provide access to the current mask from ul_debugobj(). It's better

  than modify all ul_debugobj() calls and use the global mask as

  argument.

* remove never used UL_DEBUG_DEFINE_FLAG

* remove %p from another libmount and libblkid debug messages

Upstream: http://github.com/karelzak/util-linux/commit/6d00cfb2330cb47d00d350eedfbffbbf5991a743

Addresses: https://bugzilla.redhat.com/show_bug.cgi?id=1534893

Reported-by: halfdog <me@halfdog.net>

Signed-off-by: Karel Zak <kzak@redhat.com>

---

 include/Makemodule.am                |  2 ++

 include/debug.h                      | 29 +++++++++++------------------

 include/debugobj.h                   | 22 ++++++++++++++++++++++

 lib/loopdev.c                        |  2 +-

 libblkid/src/partitions/partitions.c | 20 ++++++++++----------

 libblkid/src/probe.c                 | 21 ++++++++++-----------

 libmount/src/fs.c                    |  2 +-

 libmount/src/init.c                  |  5 +++++

 libmount/src/mountP.h                |  4 +++-

 libmount/src/tab_diff.c              |  6 +++---

 libmount/src/tab_update.c            |  4 ++--

 libsmartcols/src/smartcolsP.h        |  3 +++

 sys-utils/lsns.c                     |  3 +++

 13 files changed, 76 insertions(+), 47 deletions(-)

 create mode 100644 include/debugobj.h

diff --git a/include/Makemodule.am b/include/Makemodule.am

index 168029683..bd4aa8cea 100644

--- a/include/Makemodule.am

+++ b/include/Makemodule.am

@@ -11,6 +11,8 @@ dist_noinst_HEADERS += \

 	include/colors.h \

 	include/cpuset.h \

 	include/crc32.h \

+	include/debug.h \

+	include/debugobj.h \

 	include/env.h \

 	include/exec_shell.h \

 	include/exitcodes.h \

diff --git a/include/debug.h b/include/debug.h

index 848e47456..1c7ed8037 100644

--- a/include/debug.h

+++ b/include/debug.h

@@ -13,12 +13,15 @@

 struct dbg_mask { char *mname; int val; };

 #define UL_DEBUG_EMPTY_MASKNAMES {{ NULL, 0 }}

-#define UL_DEBUG_DEFINE_MASK(m) int m ## _debug_mask

+#define UL_DEBUG_MASK(m)         m ## _debug_mask

+#define UL_DEBUG_DEFINE_MASK(m)  int UL_DEBUG_MASK(m)

 #define UL_DEBUG_DECLARE_MASK(m) extern UL_DEBUG_DEFINE_MASK(m)

 #define UL_DEBUG_DEFINE_MASKNAMES(m) static const struct dbg_mask m ## _masknames[]

-/* p - flag prefix, m - flag postfix */

-#define UL_DEBUG_DEFINE_FLAG(p, m) p ## m

+/*

+ * Internal mask flags (above 0xffffff)

+ */

+#define __UL_DEBUG_FL_NOADDR   (1 << 24)       /* Don't print object address */

 /* l - library name, p - flag prefix, m - flag postfix, x - function */

 #define __UL_DBG(l, p, m, x) \

@@ -55,6 +58,10 @@ struct dbg_mask { char *mname; int val; };

 				lib ## _debug_mask = parse_envmask(lib ## _masknames, str); \

 		} else \

 			lib ## _debug_mask = mask; \

+		if (lib ## _debug_mask) { \

+			if (getuid() != geteuid() || getgid() != getegid()) \

+				lib ## _debug_mask |= __UL_DEBUG_FL_NOADDR; \

+		} \

 		lib ## _debug_mask |= pref ## INIT; \

 		if (lib ## _debug_mask != pref ## INIT) { \

 			__UL_DBG(lib, pref, INIT, ul_debug("library debug mask: 0x%04x", \

@@ -72,21 +79,7 @@ ul_debug(const char *mesg, ...)

 	va_end(ap);

 	fputc('\n', stderr);

 }

-

-static inline void __attribute__ ((__format__ (__printf__, 2, 3)))

-ul_debugobj(void *handler, const char *mesg, ...)

-{

-	va_list ap;

-

-	if (handler)

-		fprintf(stderr, "[%p]: ", handler);

-	va_start(ap, mesg);

-	vfprintf(stderr, mesg, ap);

-	va_end(ap);

-	fputc('\n', stderr);

-}

-

-static inline int parse_envmask(const struct dbg_mask const flagnames[],

+static inline int parse_envmask(const struct dbg_mask flagnames[],

 				const char *mask)

 {

 	int res;

diff --git a/include/debugobj.h b/include/debugobj.h

new file mode 100644

index 000000000..73b70b8df

--- /dev/null

+++ b/include/debugobj.h

@@ -0,0 +1,22 @@

+#ifndef UTIL_LINUX_DEBUGOBJ_H

+#define UTIL_LINUX_DEBUGOBJ_H

+

+/*

+ * Include *after* debug.h and after UL_DEBUG_CURRENT_MASK define.

+ */

+

+static inline void __attribute__ ((__format__ (__printf__, 2, 3)))

+ul_debugobj(const void *handler, const char *mesg, ...)

+{

+	va_list ap;

+

+	if (handler && !(UL_DEBUG_CURRENT_MASK & __UL_DEBUG_FL_NOADDR))

+		fprintf(stderr, "[%p]: ", handler);

+

+	va_start(ap, mesg);

+	vfprintf(stderr, mesg, ap);

+	va_end(ap);

+	fputc('\n', stderr);

+}

+

+#endif /* UTIL_LINUX_DEBUGOBJ_H */

diff --git a/lib/loopdev.c b/lib/loopdev.c

index db5463698..daf0a81e8 100644

--- a/lib/loopdev.c

+++ b/lib/loopdev.c

@@ -50,7 +50,7 @@

 # define DBG(l,x)	do { \

 				if ((l)->debug) {\

-					fprintf(stderr, "loopdev:  [%p]: ", (l)); \

+					fprintf(stderr, "loopdev: "); \

 					x; \

 				} \

 			} while(0)

diff --git a/libblkid/src/partitions/partitions.c b/libblkid/src/partitions/partitions.c

index 9d846ff85..2d0d70d81 100644

--- a/libblkid/src/partitions/partitions.c

+++ b/libblkid/src/partitions/partitions.c

@@ -381,8 +381,8 @@ static blkid_partlist partitions_init_data(struct blkid_chain *chn)

 	reset_partlist(ls);

-	DBG(LOWPROBE, blkid_debug("parts: initialized partitions list (%p, size=%d)",

-		ls, ls->nparts_max));

+	DBG(LOWPROBE, blkid_debug("parts: initialized partitions list (size=%d)",

+		ls->nparts_max));

 	return ls;

 }

@@ -417,7 +417,7 @@ blkid_parttable blkid_partlist_new_parttable(blkid_partlist ls,

 	list_add_tail(&tab->t_tabs, &ls->l_tabs);

 	DBG(LOWPROBE, blkid_debug("parts: create a new partition table "

-		       "(%p, type=%s, offset=%"PRId64")", tab, type, offset));

+		       "(type=%s, offset=%"PRId64")", type, offset));

 	return tab;

 }

@@ -458,9 +458,9 @@ blkid_partition blkid_partlist_add_partition(blkid_partlist ls,

 	par->start = start;

 	par->size = size;

-	DBG(LOWPROBE, blkid_debug("parts: add partition (%p start=%"

-		PRId64 ", size=%" PRId64 ", table=%p)",

-		par, par->start, par->size, tab));

+	DBG(LOWPROBE, blkid_debug("parts: add partition (start=%"

+		PRId64 ", size=%" PRId64 ")",

+		par->start, par->size));

 	return par;

 }

@@ -662,8 +662,8 @@ int blkid_partitions_do_subprobe(blkid_probe pr, blkid_partition parent,

 	blkid_loff_t sz, off;

 	DBG(LOWPROBE, blkid_debug(

-		"parts: ----> %s subprobe requested (parent=%p)",

-		id->name, parent));

+		"parts: ----> %s subprobe requested)",

+		id->name));

 	if (!pr || !parent || !parent->size)

 		return -EINVAL;

@@ -709,8 +709,8 @@ int blkid_partitions_do_subprobe(blkid_probe pr, blkid_partition parent,

 	blkid_free_probe(prc);	/* free cloned prober */

 	DBG(LOWPROBE, blkid_debug(

-		"parts: <---- %s subprobe done (parent=%p, rc=%d)",

-		id->name, parent, rc));

+		"parts: <---- %s subprobe done (rc=%d)",

+		id->name, rc));

 	return rc;

 }

diff --git a/libblkid/src/probe.c b/libblkid/src/probe.c

index 9cf099ae4..07b08441f 100644

--- a/libblkid/src/probe.c

+++ b/libblkid/src/probe.c

@@ -145,7 +145,7 @@ blkid_probe blkid_new_probe(void)

 	if (!pr)

 		return NULL;

-	DBG(LOWPROBE, blkid_debug("allocate a new probe %p", pr));

+	DBG(LOWPROBE, blkid_debug("allocate a new probe"));

 	/* initialize chains */

 	for (i = 0; i < BLKID_NCHAINS; i++) {

@@ -260,7 +260,7 @@ void blkid_free_probe(blkid_probe pr)

 	blkid_probe_reset_buffer(pr);

 	blkid_free_probe(pr->disk_probe);

-	DBG(LOWPROBE, blkid_debug("free probe %p", pr));

+	DBG(LOWPROBE, blkid_debug("free probe"));

 	free(pr);

 }

@@ -552,8 +552,8 @@ unsigned char *blkid_probe_get_buffer(blkid_probe pr,

 				list_entry(p, struct blkid_bufinfo, bufs);

 		if (x->off <= off && off + len <= x->off + x->len) {

-			DBG(LOWPROBE, blkid_debug("\treuse buffer: off=%jd len=%jd pr=%p",

-							x->off, x->len, pr));

+			DBG(LOWPROBE, blkid_debug("\treuse buffer: off=%jd len=%jd",

+							x->off, x->len));

 			bf = x;

 			break;

 		}

@@ -584,8 +584,8 @@ unsigned char *blkid_probe_get_buffer(blkid_probe pr,

 		bf->off = off;

 		INIT_LIST_HEAD(&bf->bufs);

-		DBG(LOWPROBE, blkid_debug("\tbuffer read: off=%jd len=%jd pr=%p",

-				off, len, pr));

+		DBG(LOWPROBE, blkid_debug("\tbuffer read: off=%jd len=%jd",

+				off, len));

 		ret = read(pr->fd, bf->data, len);

 		if (ret != (ssize_t) len) {

@@ -609,7 +609,7 @@ static void blkid_probe_reset_buffer(blkid_probe pr)

 	if (!pr || list_empty(&pr->buffers))

 		return;

-	DBG(LOWPROBE, blkid_debug("reseting probing buffers pr=%p", pr));

+	DBG(LOWPROBE, blkid_debug("reseting probing buffers"));

 	while (!list_empty(&pr->buffers)) {

 		struct blkid_bufinfo *bf = list_entry(pr->buffers.next,

@@ -766,9 +766,8 @@ int blkid_probe_set_dimension(blkid_probe pr,

 		return -1;

 	DBG(LOWPROBE, blkid_debug(

-		"changing probing area pr=%p: size=%llu, off=%llu "

+		"changing probing area: size=%llu, off=%llu "

 		"-to-> size=%llu, off=%llu",

-		pr,

 		(unsigned long long) pr->size,

 		(unsigned long long) pr->off,

 		(unsigned long long) size,

@@ -840,7 +839,7 @@ int blkid_probe_get_idmag(blkid_probe pr, const struct blkid_idinfo *id,

 static inline void blkid_probe_start(blkid_probe pr)

 {

 	if (pr) {

-		DBG(LOWPROBE, blkid_debug("%p: start probe", pr));

+		DBG(LOWPROBE, blkid_debug("start probe"));

 		pr->cur_chain = NULL;

 		pr->prob_flags = 0;

 		blkid_probe_set_wiper(pr, 0, 0);

@@ -850,7 +849,7 @@ static inline void blkid_probe_start(blkid_probe pr)

 static inline void blkid_probe_end(blkid_probe pr)

 {

 	if (pr) {

-		DBG(LOWPROBE, blkid_debug("%p: end probe", pr));

+		DBG(LOWPROBE, blkid_debug("end probe"));

 		pr->cur_chain = NULL;

 		pr->prob_flags = 0;

 		blkid_probe_set_wiper(pr, 0, 0);

diff --git a/libmount/src/fs.c b/libmount/src/fs.c

index 75e3bbb26..e46ee0c0e 100644

--- a/libmount/src/fs.c

+++ b/libmount/src/fs.c

@@ -1451,7 +1451,7 @@ int mnt_fs_print_debug(struct libmnt_fs *fs, FILE *file)

 {

 	if (!fs || !file)

 		return -EINVAL;

-	fprintf(file, "------ fs: %p\n", fs);

+	fprintf(file, "------ fs\n");

 	fprintf(file, "source: %s\n", mnt_fs_get_source(fs));

 	fprintf(file, "target: %s\n", mnt_fs_get_target(fs));

 	fprintf(file, "fstype: %s\n", mnt_fs_get_fstype(fs));

diff --git a/libmount/src/init.c b/libmount/src/init.c

index 4e5f489c4..e5e6925f5 100644

--- a/libmount/src/init.c

+++ b/libmount/src/init.c

@@ -38,6 +38,11 @@ void mnt_init_debug(int mask)

 	} else

 		libmount_debug_mask = mask;

+	if (libmount_debug_mask) {

+		if (getuid() != geteuid() || getgid() != getegid())

+			libmount_debug_mask |= MNT_DEBUG_FL_NOADDR;

+	}

+

 	libmount_debug_mask |= MNT_DEBUG_INIT;

 	if (libmount_debug_mask && libmount_debug_mask != MNT_DEBUG_INIT) {

diff --git a/libmount/src/mountP.h b/libmount/src/mountP.h

index 8b3f92e17..dc3ed3f49 100644

--- a/libmount/src/mountP.h

+++ b/libmount/src/mountP.h

@@ -51,6 +51,8 @@

 #define MNT_DEBUG_DIFF		(1 << 11)

 #define MNT_DEBUG_ALL		0xFFFF

+#define MNT_DEBUG_FL_NOADDR	(1 << 24)

+

 #ifdef CONFIG_LIBMOUNT_DEBUG

 # include <stdio.h>

 # include <stdarg.h>

@@ -91,7 +93,7 @@ mnt_debug_h(void *handler, const char *mesg, ...)

 {

 	va_list ap;

-	if (handler)

+	if (handler && !(libmount_debug_mask & MNT_DEBUG_FL_NOADDR))

 		fprintf(stderr, "[%p]: ", handler);

 	va_start(ap, mesg);

 	vfprintf(stderr, mesg, ap);

diff --git a/libmount/src/tab_diff.c b/libmount/src/tab_diff.c

index f01f889f8..0a69f402c 100644

--- a/libmount/src/tab_diff.c

+++ b/libmount/src/tab_diff.c

@@ -229,9 +229,9 @@ int mnt_diff_tables(struct libmnt_tabdiff *df, struct libmnt_table *old_tab,

 	if (!no && !nn)			/* both tables are empty */

 		return 0;

-	DBG(DIFF, mnt_debug_h(df, "analyze new=%p (%d entries), "

-				          "old=%p (%d entries)",

-				new_tab, nn, old_tab, no));

+	DBG(DIFF, mnt_debug_h(df, "analyze new (%d entries), "

+				          "old (%d entries)",

+				nn, no));

 	mnt_reset_iter(&itr, MNT_ITER_FORWARD);

diff --git a/libmount/src/tab_update.c b/libmount/src/tab_update.c

index 5f503cad7..b45c4a92c 100644

--- a/libmount/src/tab_update.c

+++ b/libmount/src/tab_update.c

@@ -173,8 +173,8 @@ int mnt_update_set_fs(struct libmnt_update *upd, unsigned long mountflags,

 		return -EINVAL;

 	DBG(UPDATE, mnt_debug_h(upd,

-			"resetting FS [fs=0x%p, target=%s, flags=0x%08lx]",

-			fs, target, mountflags));

+			"resetting FS [target=%s, flags=0x%08lx]",

+			target, mountflags));

 	if (fs) {

 		DBG(UPDATE, mnt_debug_h(upd, "FS template:"));

 		DBG(UPDATE, mnt_fs_print_debug(fs, stderr));

diff --git a/libsmartcols/src/smartcolsP.h b/libsmartcols/src/smartcolsP.h

index 28246c14f..cea4f3101 100644

--- a/libsmartcols/src/smartcolsP.h

+++ b/libsmartcols/src/smartcolsP.h

@@ -43,6 +43,9 @@ UL_DEBUG_DECLARE_MASK(libsmartcols);

 #define ON_DBG(m, x)	__UL_DBG_CALL(libsmartcols, SCOLS_DEBUG_, m, x)

 #define DBG_FLUSH	__UL_DBG_FLUSH(libsmartcols, SCOLS_DEBUG_)

+#define UL_DEBUG_CURRENT_MASK  UL_DEBUG_MASK(libsmartcols)

+#include "debugobj.h"

+

 /*

  * Generic iterator

  */

diff --git a/sys-utils/lsns.c b/sys-utils/lsns.c

index 5ee298172..fb53a16a4 100644

--- a/sys-utils/lsns.c

+++ b/sys-utils/lsns.c

@@ -55,6 +55,9 @@ UL_DEBUG_DEFINE_MASKNAMES(lsns) = UL_DEBUG_EMPTY_MASKNAMES;

 #define DBG(m, x)       __UL_DBG(lsns, LSNS_DEBUG_, m, x)

 #define ON_DBG(m, x)    __UL_DBG_CALL(lsns, LSNS_DEBUG_, m, x)

+#define UL_DEBUG_CURRENT_MASK  UL_DEBUG_MASK(lsns)

+#include "debugobj.h"

+

 struct idcache *uid_cache = NULL;

 /* column IDs */

-- 

2.13.6