Attachment 923019 Details for Bug 1119662 – 03-netlbl-catmap_walk_fix.patch

[patch] 03-netlbl-catmap_walk_fix.patch

03-netlbl-catmap_walk_fix.patch (text/plain), 6.04 KB, created by Paul Moore on 2014-07-31 18:26:41 UTC

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Creator: Paul Moore

Created: 2014-07-31 18:26:41 UTC

Size: 6.04 KB

patch

obsolete

>netlabel: fix the catmap walking functions
>
>From: Paul Moore <pmoore@redhat.com>
>
>The two NetLabel LSM secattr catmap walk functions didn't handle
>certain edge conditions correctly, causing incorrect security labels
>to be generated in some cases.  This patch corrects these problems and
>converts the functions to use the new _netlbl_secattr_catmap_getnode()
>function in order to reduce the amount of repeated code.
>
>Cc: stable@vger.kernel.org
>Signed-off-by: Paul Moore <pmoore@redhat.com>
>---
> net/netlabel/netlabel_kapi.c |  102 ++++++++++++++++++++++--------------------
> 1 file changed, 54 insertions(+), 48 deletions(-)
>
>diff --git a/net/netlabel/netlabel_kapi.c b/net/netlabel/netlabel_kapi.c
>index d9e1046..bc38838 100644
>--- a/net/netlabel/netlabel_kapi.c
>+++ b/net/netlabel/netlabel_kapi.c
>@@ -407,6 +407,7 @@ out_entry:
> 
> #define _CM_F_NONE	0x00000000
> #define _CM_F_ALLOC	0x00000001
>+#define _CM_F_WALK	0x00000002
> 
> /**
>  * _netlbl_secattr_catmap_getnode - Get a individual node from a catmap
>@@ -416,10 +417,11 @@ out_entry:
>  * @gfp_flags: memory allocation flags
>  *
>  * Description:
>- * Iterate through the catmap looking for the node associated with @offset; if
>- * the _CM_F_ALLOC flag is set in @cm_flags and there is no associated node,
>- * one will be created and inserted into the catmap.  Returns a pointer to the
>- * node on success, NULL on failure.
>+ * Iterate through the catmap looking for the node associated with @offset.
>+ * If the _CM_F_ALLOC flag is set in @cm_flags and there is no associated node,
>+ * one will be created and inserted into the catmap.  If the _CM_F_WALK flag is
>+ * set in @cm_flags and there is no associated node, the next highest node will
>+ * be returned.  Returns a pointer to the node on success, NULL on failure.
>  *
>  */
> static struct netlbl_lsm_secattr_catmap *_netlbl_secattr_catmap_getnode(
>@@ -431,17 +433,22 @@ static struct netlbl_lsm_secattr_catmap *_netlbl_secattr_catmap_getnode(
> 	struct netlbl_lsm_secattr_catmap *iter = *catmap;
> 	struct netlbl_lsm_secattr_catmap *prev = NULL;
> 
>-	if (iter == NULL || offset < iter->startbit)
>+	if (iter == NULL)
> 		goto secattr_catmap_getnode_alloc;
>+	if (offset < iter->startbit)
>+		goto secattr_catmap_getnode_walk;
> 	while (iter && offset >= (iter->startbit + NETLBL_CATMAP_SIZE)) {
> 		prev = iter;
> 		iter = iter->next;
> 	}
> 	if (iter == NULL || offset < iter->startbit)
>-		goto secattr_catmap_getnode_alloc;
>+		goto secattr_catmap_getnode_walk;
> 
> 	return iter;
> 
>+secattr_catmap_getnode_walk:
>+	if (cm_flags & _CM_F_WALK)
>+		return iter;
> secattr_catmap_getnode_alloc:
> 	if (!(cm_flags & _CM_F_ALLOC))
> 		return NULL;
>@@ -476,43 +483,41 @@ int netlbl_secattr_catmap_walk(struct netlbl_lsm_secattr_catmap *catmap,
> 			       u32 offset)
> {
> 	struct netlbl_lsm_secattr_catmap *iter = catmap;
>-	u32 node_idx;
>-	u32 node_bit;
>+	u32 idx;
>+	u32 bit;
> 	NETLBL_CATMAP_MAPTYPE bitmap;
> 
>+	iter = _netlbl_secattr_catmap_getnode(&catmap, offset, _CM_F_WALK, 0);
>+	if (iter == NULL)
>+		return -ENOENT;
> 	if (offset > iter->startbit) {
>-		while (offset >= (iter->startbit + NETLBL_CATMAP_SIZE)) {
>-			iter = iter->next;
>-			if (iter == NULL)
>-				return -ENOENT;
>-		}
>-		node_idx = (offset - iter->startbit) / NETLBL_CATMAP_MAPSIZE;
>-		node_bit = offset - iter->startbit -
>-			   (NETLBL_CATMAP_MAPSIZE * node_idx);
>+		offset -= iter->startbit;
>+		idx = offset / NETLBL_CATMAP_MAPSIZE;
>+		bit = offset % NETLBL_CATMAP_MAPSIZE;
> 	} else {
>-		node_idx = 0;
>-		node_bit = 0;
>+		idx = 0;
>+		bit = 0;
> 	}
>-	bitmap = iter->bitmap[node_idx] >> node_bit;
>+	bitmap = iter->bitmap[idx] >> bit;
> 
> 	for (;;) {
> 		if (bitmap != 0) {
> 			while ((bitmap & NETLBL_CATMAP_BIT) == 0) {
> 				bitmap >>= 1;
>-				node_bit++;
>+				bit++;
> 			}
> 			return iter->startbit +
>-				(NETLBL_CATMAP_MAPSIZE * node_idx) + node_bit;
>+			       (NETLBL_CATMAP_MAPSIZE * idx) + bit;
> 		}
>-		if (++node_idx >= NETLBL_CATMAP_MAPCNT) {
>+		if (++idx >= NETLBL_CATMAP_MAPCNT) {
> 			if (iter->next != NULL) {
> 				iter = iter->next;
>-				node_idx = 0;
>+				idx = 0;
> 			} else
> 				return -ENOENT;
> 		}
>-		bitmap = iter->bitmap[node_idx];
>-		node_bit = 0;
>+		bitmap = iter->bitmap[idx];
>+		bit = 0;
> 	}
> 
> 	return -ENOENT;
>@@ -532,46 +537,47 @@ int netlbl_secattr_catmap_walk(struct netlbl_lsm_secattr_catmap *catmap,
> int netlbl_secattr_catmap_walk_rng(struct netlbl_lsm_secattr_catmap *catmap,
> 				   u32 offset)
> {
>-	struct netlbl_lsm_secattr_catmap *iter = catmap;
>-	u32 node_idx;
>-	u32 node_bit;
>+	struct netlbl_lsm_secattr_catmap *iter;
>+	struct netlbl_lsm_secattr_catmap *prev = NULL;
>+	u32 idx;
>+	u32 bit;
> 	NETLBL_CATMAP_MAPTYPE bitmask;
> 	NETLBL_CATMAP_MAPTYPE bitmap;
> 
>+	iter = _netlbl_secattr_catmap_getnode(&catmap, offset, _CM_F_WALK, 0);
>+	if (iter == NULL)
>+		return -ENOENT;
> 	if (offset > iter->startbit) {
>-		while (offset >= (iter->startbit + NETLBL_CATMAP_SIZE)) {
>-			iter = iter->next;
>-			if (iter == NULL)
>-				return -ENOENT;
>-		}
>-		node_idx = (offset - iter->startbit) / NETLBL_CATMAP_MAPSIZE;
>-		node_bit = offset - iter->startbit -
>-			   (NETLBL_CATMAP_MAPSIZE * node_idx);
>+		offset -= iter->startbit;
>+		idx = offset / NETLBL_CATMAP_MAPSIZE;
>+		bit = offset % NETLBL_CATMAP_MAPSIZE;
> 	} else {
>-		node_idx = 0;
>-		node_bit = 0;
>+		idx = 0;
>+		bit = 0;
> 	}
>-	bitmask = NETLBL_CATMAP_BIT << node_bit;
>+	bitmask = NETLBL_CATMAP_BIT << bit;
> 
> 	for (;;) {
>-		bitmap = iter->bitmap[node_idx];
>+		bitmap = iter->bitmap[idx];
> 		while (bitmask != 0 && (bitmap & bitmask) != 0) {
> 			bitmask <<= 1;
>-			node_bit++;
>+			bit++;
> 		}
> 
>-		if (bitmask != 0)
>+		if (prev && idx == 0 && bit == 0)
>+			return prev->startbit + NETLBL_CATMAP_SIZE - 1;
>+		else if (bitmask != 0)
> 			return iter->startbit +
>-				(NETLBL_CATMAP_MAPSIZE * node_idx) +
>-				node_bit - 1;
>-		else if (++node_idx >= NETLBL_CATMAP_MAPCNT) {
>+				(NETLBL_CATMAP_MAPSIZE * idx) + bit - 1;
>+		else if (++idx >= NETLBL_CATMAP_MAPCNT) {
> 			if (iter->next == NULL)
>-				return iter->startbit +	NETLBL_CATMAP_SIZE - 1;
>+				return iter->startbit + NETLBL_CATMAP_SIZE - 1;
>+			prev = iter;
> 			iter = iter->next;
>-			node_idx = 0;
>+			idx = 0;
> 		}
> 		bitmask = NETLBL_CATMAP_BIT;
>-		node_bit = 0;
>+		bit = 0;
> 	}
> 
> 	return -ENOENT;

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Attachments on bug 1119662: 918084 | 923017 | 923018 | 923019 | 923020