stable - ext[234]: Avoid printk floods in the face of directory corruption (CVE-2008-3528)

PATCH In review Eric Sandeen 3 participants 10 messages Oct 22, 2008 – Oct 23, 2008

Subsystems (2)

ext4 file system ext2 file system

lore

Share & tools

lore

Eric Sandeen

author

2008-10-22 15:11 UTC #0 lore raw

PATCH 1/1 stable - ext[234]: Avoid printk floods in the face of directory corruption (CVE-2008-3528)

This is a trivial backport of the following upstream commits:

- bd39597cbd42a784105a04010100e27267481c67 (ext2)
- cdbf6dba28e8e6268c8420857696309470009fd9 (ext3)
- 9d9f177572d9e4eba0f2e18523b44f90dd51fe74 (ext4)

This addresses CVE-2008-3528

ext[234]: Avoid printk floods in the face of directory corruption

Note: some people thinks this represents a security bug, since it might make the system go away while it is printing a large number of console messages, especially if a serial console is involved. Hence, it has been assigned CVE-2008-3528, but it requires that the attacker either has physical access to your machine to insert a USB disk with a corrupted filesystem image (at which point why not just hit the power button), or is otherwise able to convince the system administrator to mount an arbitrary filesystem image (at which point why not just include a setuid shell or world-writable hard disk device file or some such). Me, I think they're just being silly. --tytso

Signed-off-by Eric Sandeen <[email protected]>

Signed-off-by "Theodore Ts'o" <[email protected]>

Cc [email protected]

Cc Eugene Teo <[email protected]>

---

fs/ext2/dir.c +35 ~~-25~~

Index: linux-2.6/fs/ext2/dir.c
===================================================================
@@ -103,7 +103,7 @@ static int ext2_commit_chunk(struct page
 	return err;
 }
 
-static void ext2_check_page(struct page *page)
+static void ext2_check_page(struct page *page, int quiet)
 {
 	struct inode *dir = page->mapping->host;
 	struct super_block *sb = dir->i_sb;

@@ -146,10 +146,10 @@ out:
 	/* Too bad, we had an error */
 
 Ebadsize:
-	ext2_error(sb, "ext2_check_page",
-		"size of directory #%lu is not a multiple of chunk size",
-		dir->i_ino
-	);
+	if (!quiet)
+		ext2_error(sb, __func__,
+			"size of directory #%lu is not a multiple "
+			"of chunk size", dir->i_ino);
 	goto fail;
 Eshort:
 	error = "rec_len is smaller than minimal";

@@ -166,32 +166,36 @@ Espan:
 Einumber:
 	error = "inode out of bounds";
 bad_entry:
-	ext2_error (sb, "ext2_check_page", "bad entry in directory #%lu: %s - "
-		"offset=%lu, inode=%lu, rec_len=%d, name_len=%d",
-		dir->i_ino, error, (page->index<<PAGE_CACHE_SHIFT)+offs,
-		(unsigned long) le32_to_cpu(p->inode),
-		rec_len, p->name_len);
+	if (!quiet)
+		ext2_error(sb, __func__, "bad entry in directory #%lu: : %s - "
+			"offset=%lu, inode=%lu, rec_len=%d, name_len=%d",
+			dir->i_ino, error, (page->index<<PAGE_CACHE_SHIFT)+offs,
+			(unsigned long) le32_to_cpu(p->inode),
+			rec_len, p->name_len);
 	goto fail;
 Eend:
-	p = (ext2_dirent *)(kaddr + offs);
-	ext2_error (sb, "ext2_check_page",
-		"entry in directory #%lu spans the page boundary"
-		"offset=%lu, inode=%lu",
-		dir->i_ino, (page->index<<PAGE_CACHE_SHIFT)+offs,
-		(unsigned long) le32_to_cpu(p->inode));
+	if (!quiet) {
+		p = (ext2_dirent *)(kaddr + offs);
+		ext2_error(sb, "ext2_check_page",
+			"entry in directory #%lu spans the page boundary"
+			"offset=%lu, inode=%lu",
+			dir->i_ino, (page->index<<PAGE_CACHE_SHIFT)+offs,
+			(unsigned long) le32_to_cpu(p->inode));
+	}
 fail:
 	SetPageChecked(page);
 	SetPageError(page);
 }
 
-static struct page * ext2_get_page(struct inode *dir, unsigned long n)
+static struct page * ext2_get_page(struct inode *dir, unsigned long n,
+				   int quiet)
 {
 	struct address_space *mapping = dir->i_mapping;
 	struct page *page = read_mapping_page(mapping, n, NULL);
 	if (!IS_ERR(page)) {
 		kmap(page);
 		if (!PageChecked(page))
-			ext2_check_page(page);
+			ext2_check_page(page, quiet);
 		if (PageError(page))
 			goto fail;
 	}

@@ -292,7 +296,7 @@ ext2_readdir (struct file * filp, void *
 	for ( ; n < npages; n++, offset = 0) {
 		char *kaddr, *limit;
 		ext2_dirent *de;
-		struct page *page = ext2_get_page(inode, n);
+		struct page *page = ext2_get_page(inode, n, 0);
 
 		if (IS_ERR(page)) {
 			ext2_error(sb, __func__,

@@ -361,6 +365,7 @@ struct ext2_dir_entry_2 * ext2_find_entr
 	struct page *page = NULL;
 	struct ext2_inode_info *ei = EXT2_I(dir);
 	ext2_dirent * de;
+	int dir_has_error = 0;
 
 	if (npages == 0)
 		goto out;

@@ -374,7 +379,7 @@ struct ext2_dir_entry_2 * ext2_find_entr
 	n = start;
 	do {
 		char *kaddr;
-		page = ext2_get_page(dir, n);
+		page = ext2_get_page(dir, n, dir_has_error);
 		if (!IS_ERR(page)) {
 			kaddr = page_address(page);
 			de = (ext2_dirent *) kaddr;

@@ -391,7 +396,9 @@ struct ext2_dir_entry_2 * ext2_find_entr
 				de = ext2_next_entry(de);
 			}
 			ext2_put_page(page);
-		}
+		} else
+			dir_has_error = 1;
+
 		if (++n >= npages)
 			n = 0;
 		/* next page is past the blocks we've got */

@@ -414,7 +421,7 @@ found:
 
 struct ext2_dir_entry_2 * ext2_dotdot (struct inode *dir, struct page **p)
 {
-	struct page *page = ext2_get_page(dir, 0);
+	struct page *page = ext2_get_page(dir, 0, 0);
 	ext2_dirent *de = NULL;
 
 	if (!IS_ERR(page)) {

@@ -487,7 +494,7 @@ int ext2_add_link (struct dentry *dentry
 	for (n = 0; n <= npages; n++) {
 		char *dir_end;
 
-		page = ext2_get_page(dir, n);
+		page = ext2_get_page(dir, n, 0);
 		err = PTR_ERR(page);
 		if (IS_ERR(page))
 			goto out;

@@ -655,14 +662,17 @@ int ext2_empty_dir (struct inode * inode
 {
 	struct page *page = NULL;
 	unsigned long i, npages = dir_pages(inode);
+	int dir_has_error = 0;
 
 	for (i = 0; i < npages; i++) {
 		char *kaddr;
 		ext2_dirent * de;
-		page = ext2_get_page(inode, i);
+		page = ext2_get_page(inode, i, dir_has_error);
 
-		if (IS_ERR(page))
+		if (IS_ERR(page)) {
+			dir_has_error = 1;
 			continue;
+		}
 
 		kaddr = page_address(page);
 		de = (ext2_dirent *)kaddr;

fs/ext3/dir.c +7 -3

Index: linux-2.6/fs/ext3/dir.c
===================================================================
@@ -102,6 +102,7 @@ static int ext3_readdir(struct file * fi
 	int err;
 	struct inode *inode = filp->f_path.dentry->d_inode;
 	int ret = 0;
+	int dir_has_error = 0;
 
 	sb = inode->i_sb;

@@ -148,9 +149,12 @@ static int ext3_readdir(struct file * fi
 		 * of recovering data when there's a bad sector
 		 */
 		if (!bh) {
-			ext3_error (sb, "ext3_readdir",
-				"directory #%lu contains a hole at offset %lu",
-				inode->i_ino, (unsigned long)filp->f_pos);
+			if (!dir_has_error) {
+				ext3_error(sb, __func__, "directory #%lu "
+					"contains a hole at offset %lld",
+					inode->i_ino, filp->f_pos);
+				dir_has_error = 1;
+			}
 			/* corrupt size?  Maybe no more blocks to read */
 			if (filp->f_pos > inode->i_blocks << 9)
 				break;

fs/ext4/dir.c +8 -3

Index: linux-2.6/fs/ext4/dir.c
===================================================================
@@ -102,6 +102,7 @@ static int ext4_readdir(struct file * fi
 	int err;
 	struct inode *inode = filp->f_path.dentry->d_inode;
 	int ret = 0;
+	int dir_has_error = 0;
 
 	sb = inode->i_sb;

@@ -148,9 +149,13 @@ static int ext4_readdir(struct file * fi
 		 * of recovering data when there's a bad sector
 		 */
 		if (!bh) {
-			ext4_error (sb, "ext4_readdir",
-				"directory #%lu contains a hole at offset %lu",
-				inode->i_ino, (unsigned long)filp->f_pos);
+			if (!dir_has_error) {
+				ext4_error(sb, __func__, "directory #%lu "
+					   "contains a hole at offset %Lu",
+					   inode->i_ino,
+					   (unsigned long long) filp->f_pos);
+				dir_has_error = 1;
+			}
 			/* corrupt size?  Maybe no more blocks to read */
 			if (filp->f_pos > inode->i_blocks << 9)
 				break;

Greg KH

2008-10-22 16:17 UTC #1 lore raw

Quoted 9 lines · Eric Sandeen

This is a trivial backport of the following upstream commits:
- bd39597cbd42a784105a04010100e27267481c67 (ext2)
- cdbf6dba28e8e6268c8420857696309470009fd9 (ext3)
- 9d9f177572d9e4eba0f2e18523b44f90dd51fe74 (ext4)
This addresses CVE-2008-3528
ext[234]: Avoid printk floods in the face of directory corruption

For what kernel releases is this applicable? .27? .26? .25? Earlier?

thanks,

greg k-h

Eric Sandeen

author

2008-10-22 16:21 UTC #2 lore raw

Quoted 7 lines · Greg KH

Quoted 6 lines · Eric Sandeen
This is a trivial backport of the following upstream commits:
- bd39597cbd42a784105a04010100e27267481c67 (ext2)
- cdbf6dba28e8e6268c8420857696309470009fd9 (ext3)
- 9d9f177572d9e4eba0f2e18523b44f90dd51fe74 (ext4)

Quoted 5 lines

Quoted 3 lines
This addresses CVE-2008-3528
ext[234]: Avoid printk floods in the face of directory corruption
For what kernel releases is this applicable? .27? .26? .25? Earlier?

Sorry.. it is applicable to pretty much any kernel in the past :) .27 certainly (that's what the patch is against), .26, .25.... yes.

It's not a particularly dangerous condition - you have to somehow get the administrator to mount the filesystem before you can trigger the "exploit" (which is a DoS, essentially) - so, I don't know if it's worth porting back to the dawn of time...

Thanks,
-Eric

Quoted 3 lines

thanks,
greg k-h

Greg KH

2008-10-22 17:03 UTC #3 lore raw

Quoted 14 lines · Eric Sandeen

Quoted 7 lines · Greg KH
Quoted 6 lines · Eric Sandeen
This is a trivial backport of the following upstream commits:
- bd39597cbd42a784105a04010100e27267481c67 (ext2)
- cdbf6dba28e8e6268c8420857696309470009fd9 (ext3)
- 9d9f177572d9e4eba0f2e18523b44f90dd51fe74 (ext4)
Quoted 5 lines
Quoted 3 lines
This addresses CVE-2008-3528
ext[234]: Avoid printk floods in the face of directory corruption
For what kernel releases is this applicable? .27? .26? .25? Earlier?

Quoted 7 lines

Sorry.. it is applicable to pretty much any kernel in the past :) .27 certainly (that's what the patch is against), .26, .25.... yes.
It's not a particularly dangerous condition - you have to somehow get the administrator to mount the filesystem before you can trigger the "exploit" (which is a DoS, essentially) - so, I don't know if it's worth porting back to the dawn of time...

Well, I will not port it back to older kernels than .25, so that's not a big deal.

As for the "admin mount a filesystem", you could put an ext2/3 fs on a usb stick and plug it into a box. It will be mounted automatically, no admin rights required, and the DoS would happen, right?

thanks,

greg k-h

Eric Sandeen

author

2008-10-22 17:35 UTC #4 lore raw

Quoted 21 lines · Greg KH

Quoted 11 lines · Eric Sandeen
Quoted 10 lines · Greg KH
Quoted 9 lines · Eric Sandeen
This is a trivial backport of the following upstream commits:
- bd39597cbd42a784105a04010100e27267481c67 (ext2)
- cdbf6dba28e8e6268c8420857696309470009fd9 (ext3)
- 9d9f177572d9e4eba0f2e18523b44f90dd51fe74 (ext4)
This addresses CVE-2008-3528
ext[234]: Avoid printk floods in the face of directory corruption
Quoted 8 lines
Quoted 1 line
For what kernel releases is this applicable? .27? .26? .25? Earlier?
Sorry.. it is applicable to pretty much any kernel in the past :) .27 certainly (that's what the patch is against), .26, .25.... yes.
It's not a particularly dangerous condition - you have to somehow get the administrator to mount the filesystem before you can trigger the "exploit" (which is a DoS, essentially) - so, I don't know if it's worth porting back to the dawn of time...

Quoted 6 lines

Well, I will not port it back to older kernels than .25, so that's not a big deal.
As for the "admin mount a filesystem", you could put an ext2/3 fs on a usb stick and plug it into a box. It will be mounted automatically, no admin rights required, and the DoS would happen, right?

If I wanted to DoS a box sitting in front of me, I'd just pull the plug.

-Eric

Greg KH

2008-10-22 17:43 UTC #5 lore raw

Quoted 22 lines · Eric Sandeen

Quoted 21 lines · Greg KH
Quoted 19 lines · Eric Sandeen
Quoted 11 lines · Greg KH
Quoted 9 lines · Eric Sandeen
This is a trivial backport of the following upstream commits:
- bd39597cbd42a784105a04010100e27267481c67 (ext2)
- cdbf6dba28e8e6268c8420857696309470009fd9 (ext3)
- 9d9f177572d9e4eba0f2e18523b44f90dd51fe74 (ext4)
This addresses CVE-2008-3528
ext[234]: Avoid printk floods in the face of directory corruption
For what kernel releases is this applicable? .27? .26? .25? Earlier?
Sorry.. it is applicable to pretty much any kernel in the past :) .27 certainly (that's what the patch is against), .26, .25.... yes.
It's not a particularly dangerous condition - you have to somehow get the administrator to mount the filesystem before you can trigger the "exploit" (which is a DoS, essentially) - so, I don't know if it's worth porting back to the dawn of time...

Quoted 8 lines

Quoted 6 lines
Well, I will not port it back to older kernels than .25, so that's not a big deal.
As for the "admin mount a filesystem", you could put an ext2/3 fs on a usb stick and plug it into a box. It will be mounted automatically, no admin rights required, and the DoS would happen, right?
If I wanted to DoS a box sitting in front of me, I'd just pull the plug.

Yes, the fun "physical access" issue, right?

But for some, who run Linux in a "kiosk" mode, or in semi-secured places like university labs, something like this would matter, so you might want to notify the distros of this issue through vendor-sec and let them make up their minds if they wish to backport the fixes to their supported releases.

thanks,

greg k-h

Eric Sandeen

author

2008-10-22 19:34 UTC #6 lore raw

Quoted 7 lines · Greg KH

Yes, the fun "physical access" issue, right?
But for some, who run Linux in a "kiosk" mode, or in semi-secured places like university labs, something like this would matter, so you might want to notify the distros of this issue through vendor-sec and let them make up their minds if they wish to backport the fixes to their supported releases.

Well, the CVE should do that, right... distro security teams should be looking at the CVEs.

-Eric

[email protected]

2008-10-23 21:02 UTC #7 lore raw

patch ext-avoid-printk-floods-in-the-face-of-directory-corruption.patch added to 2.6.27-stable tree

In reply to Eric Sandeen

This is a note to let you know that we have just queued up the patch titled

Subject: ext[234]: Avoid printk floods in the face of directory corruption (CVE-2008-3528)

to the 2.6.27-stable tree. Its filename is

ext-avoid-printk-floods-in-the-face-of-directory-corruption.patch

A git repo of this tree can be found at
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

Quoted 1 line

From [email protected] Thu Oct 23 13:13:44 2008

From: Eric Sandeen <[email protected]>
Date: Wed, 22 Oct 2008 10:11:52 -0500
Subject: ext[234]: Avoid printk floods in the face of directory corruption (CVE-2008-3528)
To: [email protected]
Cc: ext4 development <[email protected]>
Message-ID: <[email protected]>

From: Eric Sandeen <[email protected]>

This is a trivial backport of the following upstream commits:

- bd39597cbd42a784105a04010100e27267481c67 (ext2)
- cdbf6dba28e8e6268c8420857696309470009fd9 (ext3)
- 9d9f177572d9e4eba0f2e18523b44f90dd51fe74 (ext4)

This addresses CVE-2008-3528

ext[234]: Avoid printk floods in the face of directory corruption

Signed-off-by Eric Sandeen <[email protected]>

Signed-off-by "Theodore Ts'o" <[email protected]>

Cc [email protected]

Cc Eugene Teo <[email protected]>

Signed-off-by Greg Kroah-Hartman <[email protected]>

---
 fs/ext2/dir.c |   60 +++++++++++++++++++++++++++++++++-------------------------
 fs/ext3/dir.c |   10 ++++++---
 fs/ext4/dir.c |   11 +++++++---
 3 files changed, 50 insertions(+), 31 deletions(-)

fs/ext2/dir.c +35 ~~-25~~

@@ -103,7 +103,7 @@ static int ext2_commit_chunk(struct page
 	return err;
 }
 
-static void ext2_check_page(struct page *page)
+static void ext2_check_page(struct page *page, int quiet)
 {
 	struct inode *dir = page->mapping->host;
 	struct super_block *sb = dir->i_sb;

@@ -146,10 +146,10 @@ out:
 	/* Too bad, we had an error */
 
 Ebadsize:
-	ext2_error(sb, "ext2_check_page",
-		"size of directory #%lu is not a multiple of chunk size",
-		dir->i_ino
-	);
+	if (!quiet)
+		ext2_error(sb, __func__,
+			"size of directory #%lu is not a multiple "
+			"of chunk size", dir->i_ino);
 	goto fail;
 Eshort:
 	error = "rec_len is smaller than minimal";

@@ -166,32 +166,36 @@ Espan:
 Einumber:
 	error = "inode out of bounds";
 bad_entry:
-	ext2_error (sb, "ext2_check_page", "bad entry in directory #%lu: %s - "
-		"offset=%lu, inode=%lu, rec_len=%d, name_len=%d",
-		dir->i_ino, error, (page->index<<PAGE_CACHE_SHIFT)+offs,
-		(unsigned long) le32_to_cpu(p->inode),
-		rec_len, p->name_len);
+	if (!quiet)
+		ext2_error(sb, __func__, "bad entry in directory #%lu: : %s - "
+			"offset=%lu, inode=%lu, rec_len=%d, name_len=%d",
+			dir->i_ino, error, (page->index<<PAGE_CACHE_SHIFT)+offs,
+			(unsigned long) le32_to_cpu(p->inode),
+			rec_len, p->name_len);
 	goto fail;
 Eend:
-	p = (ext2_dirent *)(kaddr + offs);
-	ext2_error (sb, "ext2_check_page",
-		"entry in directory #%lu spans the page boundary"
-		"offset=%lu, inode=%lu",
-		dir->i_ino, (page->index<<PAGE_CACHE_SHIFT)+offs,
-		(unsigned long) le32_to_cpu(p->inode));
+	if (!quiet) {
+		p = (ext2_dirent *)(kaddr + offs);
+		ext2_error(sb, "ext2_check_page",
+			"entry in directory #%lu spans the page boundary"
+			"offset=%lu, inode=%lu",
+			dir->i_ino, (page->index<<PAGE_CACHE_SHIFT)+offs,
+			(unsigned long) le32_to_cpu(p->inode));
+	}
 fail:
 	SetPageChecked(page);
 	SetPageError(page);
 }
 
-static struct page * ext2_get_page(struct inode *dir, unsigned long n)
+static struct page * ext2_get_page(struct inode *dir, unsigned long n,
+				   int quiet)
 {
 	struct address_space *mapping = dir->i_mapping;
 	struct page *page = read_mapping_page(mapping, n, NULL);
 	if (!IS_ERR(page)) {
 		kmap(page);
 		if (!PageChecked(page))
-			ext2_check_page(page);
+			ext2_check_page(page, quiet);
 		if (PageError(page))
 			goto fail;
 	}

@@ -292,7 +296,7 @@ ext2_readdir (struct file * filp, void *
 	for ( ; n < npages; n++, offset = 0) {
 		char *kaddr, *limit;
 		ext2_dirent *de;
-		struct page *page = ext2_get_page(inode, n);
+		struct page *page = ext2_get_page(inode, n, 0);
 
 		if (IS_ERR(page)) {
 			ext2_error(sb, __func__,

@@ -361,6 +365,7 @@ struct ext2_dir_entry_2 * ext2_find_entr
 	struct page *page = NULL;
 	struct ext2_inode_info *ei = EXT2_I(dir);
 	ext2_dirent * de;
+	int dir_has_error = 0;
 
 	if (npages == 0)
 		goto out;

@@ -374,7 +379,7 @@ struct ext2_dir_entry_2 * ext2_find_entr
 	n = start;
 	do {
 		char *kaddr;
-		page = ext2_get_page(dir, n);
+		page = ext2_get_page(dir, n, dir_has_error);
 		if (!IS_ERR(page)) {
 			kaddr = page_address(page);
 			de = (ext2_dirent *) kaddr;

@@ -391,7 +396,9 @@ struct ext2_dir_entry_2 * ext2_find_entr
 				de = ext2_next_entry(de);
 			}
 			ext2_put_page(page);
-		}
+		} else
+			dir_has_error = 1;
+
 		if (++n >= npages)
 			n = 0;
 		/* next page is past the blocks we've got */

@@ -414,7 +421,7 @@ found:
 
 struct ext2_dir_entry_2 * ext2_dotdot (struct inode *dir, struct page **p)
 {
-	struct page *page = ext2_get_page(dir, 0);
+	struct page *page = ext2_get_page(dir, 0, 0);
 	ext2_dirent *de = NULL;
 
 	if (!IS_ERR(page)) {

@@ -487,7 +494,7 @@ int ext2_add_link (struct dentry *dentry
 	for (n = 0; n <= npages; n++) {
 		char *dir_end;
 
-		page = ext2_get_page(dir, n);
+		page = ext2_get_page(dir, n, 0);
 		err = PTR_ERR(page);
 		if (IS_ERR(page))
 			goto out;

@@ -655,14 +662,17 @@ int ext2_empty_dir (struct inode * inode
 {
 	struct page *page = NULL;
 	unsigned long i, npages = dir_pages(inode);
+	int dir_has_error = 0;
 
 	for (i = 0; i < npages; i++) {
 		char *kaddr;
 		ext2_dirent * de;
-		page = ext2_get_page(inode, i);
+		page = ext2_get_page(inode, i, dir_has_error);
 
-		if (IS_ERR(page))
+		if (IS_ERR(page)) {
+			dir_has_error = 1;
 			continue;
+		}
 
 		kaddr = page_address(page);
 		de = (ext2_dirent *)kaddr;

fs/ext3/dir.c +7 -3

@@ -102,6 +102,7 @@ static int ext3_readdir(struct file * fi
 	int err;
 	struct inode *inode = filp->f_path.dentry->d_inode;
 	int ret = 0;
+	int dir_has_error = 0;
 
 	sb = inode->i_sb;

@@ -148,9 +149,12 @@ static int ext3_readdir(struct file * fi
 		 * of recovering data when there's a bad sector
 		 */
 		if (!bh) {
-			ext3_error (sb, "ext3_readdir",
-				"directory #%lu contains a hole at offset %lu",
-				inode->i_ino, (unsigned long)filp->f_pos);
+			if (!dir_has_error) {
+				ext3_error(sb, __func__, "directory #%lu "
+					"contains a hole at offset %lld",
+					inode->i_ino, filp->f_pos);
+				dir_has_error = 1;
+			}
 			/* corrupt size?  Maybe no more blocks to read */
 			if (filp->f_pos > inode->i_blocks << 9)
 				break;

fs/ext4/dir.c +8 -3

@@ -102,6 +102,7 @@ static int ext4_readdir(struct file * fi
 	int err;
 	struct inode *inode = filp->f_path.dentry->d_inode;
 	int ret = 0;
+	int dir_has_error = 0;
 
 	sb = inode->i_sb;

@@ -148,9 +149,13 @@ static int ext4_readdir(struct file * fi
 		 * of recovering data when there's a bad sector
 		 */
 		if (!bh) {
-			ext4_error (sb, "ext4_readdir",
-				"directory #%lu contains a hole at offset %lu",
-				inode->i_ino, (unsigned long)filp->f_pos);
+			if (!dir_has_error) {
+				ext4_error(sb, __func__, "directory #%lu "
+					   "contains a hole at offset %Lu",
+					   inode->i_ino,
+					   (unsigned long long) filp->f_pos);
+				dir_has_error = 1;
+			}
 			/* corrupt size?  Maybe no more blocks to read */
 			if (filp->f_pos > inode->i_blocks << 9)
 				break;

Patches currently in stable-queue which might be from [email protected] are

queue-2.6.27/ext-avoid-printk-floods-in-the-face-of-directory-corruption.patch

[email protected]

2008-10-23 21:15 UTC #8 lore raw

patch ext-avoid-printk-floods-in-the-face-of-directory-corruption.patch added to 2.6.25-stable tree

In reply to Eric Sandeen

This is a note to let you know that we have just queued up the patch titled

Subject: ext[234]: Avoid printk floods in the face of directory corruption (CVE-2008-3528)

to the 2.6.25-stable tree. Its filename is

ext-avoid-printk-floods-in-the-face-of-directory-corruption.patch

A git repo of this tree can be found at
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

Quoted 1 line

From [email protected] Thu Oct 23 13:13:44 2008

From: Eric Sandeen <[email protected]>

This is a trivial backport of the following upstream commits:

- bd39597cbd42a784105a04010100e27267481c67 (ext2)
- cdbf6dba28e8e6268c8420857696309470009fd9 (ext3)
- 9d9f177572d9e4eba0f2e18523b44f90dd51fe74 (ext4)

This addresses CVE-2008-3528

ext[234]: Avoid printk floods in the face of directory corruption

Signed-off-by Eric Sandeen <[email protected]>

Signed-off-by "Theodore Ts'o" <[email protected]>

Cc [email protected]

Cc Eugene Teo <[email protected]>

Signed-off-by Greg Kroah-Hartman <[email protected]>

---
 fs/ext2/dir.c |   60 +++++++++++++++++++++++++++++++++-------------------------
 fs/ext3/dir.c |   10 ++++++---
 fs/ext4/dir.c |   11 +++++++---
 3 files changed, 50 insertions(+), 31 deletions(-)

fs/ext2/dir.c +35 ~~-25~~

@@ -103,7 +103,7 @@ static int ext2_commit_chunk(struct page
 	return err;
 }
 
-static void ext2_check_page(struct page *page)
+static void ext2_check_page(struct page *page, int quiet)
 {
 	struct inode *dir = page->mapping->host;
 	struct super_block *sb = dir->i_sb;

@@ -146,10 +146,10 @@ out:
 	/* Too bad, we had an error */
 
 Ebadsize:
-	ext2_error(sb, "ext2_check_page",
-		"size of directory #%lu is not a multiple of chunk size",
-		dir->i_ino
-	);
+	if (!quiet)
+		ext2_error(sb, __func__,
+			"size of directory #%lu is not a multiple "
+			"of chunk size", dir->i_ino);
 	goto fail;
 Eshort:
 	error = "rec_len is smaller than minimal";

@@ -166,32 +166,36 @@ Espan:
 Einumber:
 	error = "inode out of bounds";
 bad_entry:
-	ext2_error (sb, "ext2_check_page", "bad entry in directory #%lu: %s - "
-		"offset=%lu, inode=%lu, rec_len=%d, name_len=%d",
-		dir->i_ino, error, (page->index<<PAGE_CACHE_SHIFT)+offs,
-		(unsigned long) le32_to_cpu(p->inode),
-		rec_len, p->name_len);
+	if (!quiet)
+		ext2_error(sb, __func__, "bad entry in directory #%lu: : %s - "
+			"offset=%lu, inode=%lu, rec_len=%d, name_len=%d",
+			dir->i_ino, error, (page->index<<PAGE_CACHE_SHIFT)+offs,
+			(unsigned long) le32_to_cpu(p->inode),
+			rec_len, p->name_len);
 	goto fail;
 Eend:
-	p = (ext2_dirent *)(kaddr + offs);
-	ext2_error (sb, "ext2_check_page",
-		"entry in directory #%lu spans the page boundary"
-		"offset=%lu, inode=%lu",
-		dir->i_ino, (page->index<<PAGE_CACHE_SHIFT)+offs,
-		(unsigned long) le32_to_cpu(p->inode));
+	if (!quiet) {
+		p = (ext2_dirent *)(kaddr + offs);
+		ext2_error(sb, "ext2_check_page",
+			"entry in directory #%lu spans the page boundary"
+			"offset=%lu, inode=%lu",
+			dir->i_ino, (page->index<<PAGE_CACHE_SHIFT)+offs,
+			(unsigned long) le32_to_cpu(p->inode));
+	}
 fail:
 	SetPageChecked(page);
 	SetPageError(page);
 }
 
-static struct page * ext2_get_page(struct inode *dir, unsigned long n)
+static struct page * ext2_get_page(struct inode *dir, unsigned long n,
+				   int quiet)
 {
 	struct address_space *mapping = dir->i_mapping;
 	struct page *page = read_mapping_page(mapping, n, NULL);
 	if (!IS_ERR(page)) {
 		kmap(page);
 		if (!PageChecked(page))
-			ext2_check_page(page);
+			ext2_check_page(page, quiet);
 		if (PageError(page))
 			goto fail;
 	}

@@ -292,7 +296,7 @@ ext2_readdir (struct file * filp, void *
 	for ( ; n < npages; n++, offset = 0) {
 		char *kaddr, *limit;
 		ext2_dirent *de;
-		struct page *page = ext2_get_page(inode, n);
+		struct page *page = ext2_get_page(inode, n, 0);
 
 		if (IS_ERR(page)) {
 			ext2_error(sb, __FUNCTION__,

@@ -361,6 +365,7 @@ struct ext2_dir_entry_2 * ext2_find_entr
 	struct page *page = NULL;
 	struct ext2_inode_info *ei = EXT2_I(dir);
 	ext2_dirent * de;
+	int dir_has_error = 0;
 
 	if (npages == 0)
 		goto out;

@@ -374,7 +379,7 @@ struct ext2_dir_entry_2 * ext2_find_entr
 	n = start;
 	do {
 		char *kaddr;
-		page = ext2_get_page(dir, n);
+		page = ext2_get_page(dir, n, dir_has_error);
 		if (!IS_ERR(page)) {
 			kaddr = page_address(page);
 			de = (ext2_dirent *) kaddr;

@@ -391,7 +396,9 @@ struct ext2_dir_entry_2 * ext2_find_entr
 				de = ext2_next_entry(de);
 			}
 			ext2_put_page(page);
-		}
+		} else
+			dir_has_error = 1;
+
 		if (++n >= npages)
 			n = 0;
 		/* next page is past the blocks we've got */

@@ -414,7 +421,7 @@ found:
 
 struct ext2_dir_entry_2 * ext2_dotdot (struct inode *dir, struct page **p)
 {
-	struct page *page = ext2_get_page(dir, 0);
+	struct page *page = ext2_get_page(dir, 0, 0);
 	ext2_dirent *de = NULL;
 
 	if (!IS_ERR(page)) {

@@ -487,7 +494,7 @@ int ext2_add_link (struct dentry *dentry
 	for (n = 0; n <= npages; n++) {
 		char *dir_end;
 
-		page = ext2_get_page(dir, n);
+		page = ext2_get_page(dir, n, 0);
 		err = PTR_ERR(page);
 		if (IS_ERR(page))
 			goto out;

@@ -655,14 +662,17 @@ int ext2_empty_dir (struct inode * inode
 {
 	struct page *page = NULL;
 	unsigned long i, npages = dir_pages(inode);
+	int dir_has_error = 0;
 
 	for (i = 0; i < npages; i++) {
 		char *kaddr;
 		ext2_dirent * de;
-		page = ext2_get_page(inode, i);
+		page = ext2_get_page(inode, i, dir_has_error);
 
-		if (IS_ERR(page))
+		if (IS_ERR(page)) {
+			dir_has_error = 1;
 			continue;
+		}
 
 		kaddr = page_address(page);
 		de = (ext2_dirent *)kaddr;

fs/ext3/dir.c +7 -3

@@ -102,6 +102,7 @@ static int ext3_readdir(struct file * fi
 	int err;
 	struct inode *inode = filp->f_path.dentry->d_inode;
 	int ret = 0;
+	int dir_has_error = 0;
 
 	sb = inode->i_sb;

@@ -148,9 +149,12 @@ static int ext3_readdir(struct file * fi
 		 * of recovering data when there's a bad sector
 		 */
 		if (!bh) {
-			ext3_error (sb, "ext3_readdir",
-				"directory #%lu contains a hole at offset %lu",
-				inode->i_ino, (unsigned long)filp->f_pos);
+			if (!dir_has_error) {
+				ext3_error(sb, __func__, "directory #%lu "
+					"contains a hole at offset %lld",
+					inode->i_ino, filp->f_pos);
+				dir_has_error = 1;
+			}
 			/* corrupt size?  Maybe no more blocks to read */
 			if (filp->f_pos > inode->i_blocks << 9)
 				break;

fs/ext4/dir.c +8 -3

@@ -102,6 +102,7 @@ static int ext4_readdir(struct file * fi
 	int err;
 	struct inode *inode = filp->f_path.dentry->d_inode;
 	int ret = 0;
+	int dir_has_error = 0;
 
 	sb = inode->i_sb;

@@ -147,9 +148,13 @@ static int ext4_readdir(struct file * fi
 		 * of recovering data when there's a bad sector
 		 */
 		if (!bh) {
-			ext4_error (sb, "ext4_readdir",
-				"directory #%lu contains a hole at offset %lu",
-				inode->i_ino, (unsigned long)filp->f_pos);
+			if (!dir_has_error) {
+				ext4_error(sb, __func__, "directory #%lu "
+					   "contains a hole at offset %Lu",
+					   inode->i_ino,
+					   (unsigned long long) filp->f_pos);
+				dir_has_error = 1;
+			}
 			/* corrupt size?  Maybe no more blocks to read */
 			if (filp->f_pos > inode->i_blocks << 9)
 				break;

Patches currently in stable-queue which might be from [email protected] are

queue-2.6.25/ext-avoid-printk-floods-in-the-face-of-directory-corruption.patch

[email protected]

2008-10-23 21:16 UTC #9 lore raw

patch ext-avoid-printk-floods-in-the-face-of-directory-corruption.patch added to 2.6.26-stable tree

In reply to Eric Sandeen

This is a note to let you know that we have just queued up the patch titled

Subject: ext[234]: Avoid printk floods in the face of directory corruption (CVE-2008-3528)

to the 2.6.26-stable tree. Its filename is

ext-avoid-printk-floods-in-the-face-of-directory-corruption.patch

A git repo of this tree can be found at
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

Quoted 1 line

From [email protected] Thu Oct 23 13:13:44 2008

From: Eric Sandeen <[email protected]>

This is a trivial backport of the following upstream commits:

- bd39597cbd42a784105a04010100e27267481c67 (ext2)
- cdbf6dba28e8e6268c8420857696309470009fd9 (ext3)
- 9d9f177572d9e4eba0f2e18523b44f90dd51fe74 (ext4)

This addresses CVE-2008-3528

ext[234]: Avoid printk floods in the face of directory corruption

Signed-off-by Eric Sandeen <[email protected]>

Signed-off-by "Theodore Ts'o" <[email protected]>

Cc [email protected]

Cc Eugene Teo <[email protected]>

Signed-off-by Greg Kroah-Hartman <[email protected]>

---
 fs/ext2/dir.c |   60 +++++++++++++++++++++++++++++++++-------------------------
 fs/ext3/dir.c |   10 ++++++---
 fs/ext4/dir.c |   11 +++++++---
 3 files changed, 50 insertions(+), 31 deletions(-)

fs/ext2/dir.c +35 ~~-25~~

@@ -103,7 +103,7 @@ static int ext2_commit_chunk(struct page
 	return err;
 }
 
-static void ext2_check_page(struct page *page)
+static void ext2_check_page(struct page *page, int quiet)
 {
 	struct inode *dir = page->mapping->host;
 	struct super_block *sb = dir->i_sb;

@@ -146,10 +146,10 @@ out:
 	/* Too bad, we had an error */
 
 Ebadsize:
-	ext2_error(sb, "ext2_check_page",
-		"size of directory #%lu is not a multiple of chunk size",
-		dir->i_ino
-	);
+	if (!quiet)
+		ext2_error(sb, __func__,
+			"size of directory #%lu is not a multiple "
+			"of chunk size", dir->i_ino);
 	goto fail;
 Eshort:
 	error = "rec_len is smaller than minimal";

@@ -166,32 +166,36 @@ Espan:
 Einumber:
 	error = "inode out of bounds";
 bad_entry:
-	ext2_error (sb, "ext2_check_page", "bad entry in directory #%lu: %s - "
-		"offset=%lu, inode=%lu, rec_len=%d, name_len=%d",
-		dir->i_ino, error, (page->index<<PAGE_CACHE_SHIFT)+offs,
-		(unsigned long) le32_to_cpu(p->inode),
-		rec_len, p->name_len);
+	if (!quiet)
+		ext2_error(sb, __func__, "bad entry in directory #%lu: : %s - "
+			"offset=%lu, inode=%lu, rec_len=%d, name_len=%d",
+			dir->i_ino, error, (page->index<<PAGE_CACHE_SHIFT)+offs,
+			(unsigned long) le32_to_cpu(p->inode),
+			rec_len, p->name_len);
 	goto fail;
 Eend:
-	p = (ext2_dirent *)(kaddr + offs);
-	ext2_error (sb, "ext2_check_page",
-		"entry in directory #%lu spans the page boundary"
-		"offset=%lu, inode=%lu",
-		dir->i_ino, (page->index<<PAGE_CACHE_SHIFT)+offs,
-		(unsigned long) le32_to_cpu(p->inode));
+	if (!quiet) {
+		p = (ext2_dirent *)(kaddr + offs);
+		ext2_error(sb, "ext2_check_page",
+			"entry in directory #%lu spans the page boundary"
+			"offset=%lu, inode=%lu",
+			dir->i_ino, (page->index<<PAGE_CACHE_SHIFT)+offs,
+			(unsigned long) le32_to_cpu(p->inode));
+	}
 fail:
 	SetPageChecked(page);
 	SetPageError(page);
 }
 
-static struct page * ext2_get_page(struct inode *dir, unsigned long n)
+static struct page * ext2_get_page(struct inode *dir, unsigned long n,
+				   int quiet)
 {
 	struct address_space *mapping = dir->i_mapping;
 	struct page *page = read_mapping_page(mapping, n, NULL);
 	if (!IS_ERR(page)) {
 		kmap(page);
 		if (!PageChecked(page))
-			ext2_check_page(page);
+			ext2_check_page(page, quiet);
 		if (PageError(page))
 			goto fail;
 	}

@@ -292,7 +296,7 @@ ext2_readdir (struct file * filp, void *
 	for ( ; n < npages; n++, offset = 0) {
 		char *kaddr, *limit;
 		ext2_dirent *de;
-		struct page *page = ext2_get_page(inode, n);
+		struct page *page = ext2_get_page(inode, n, 0);
 
 		if (IS_ERR(page)) {
 			ext2_error(sb, __func__,

@@ -361,6 +365,7 @@ struct ext2_dir_entry_2 * ext2_find_entr
 	struct page *page = NULL;
 	struct ext2_inode_info *ei = EXT2_I(dir);
 	ext2_dirent * de;
+	int dir_has_error = 0;
 
 	if (npages == 0)
 		goto out;

@@ -374,7 +379,7 @@ struct ext2_dir_entry_2 * ext2_find_entr
 	n = start;
 	do {
 		char *kaddr;
-		page = ext2_get_page(dir, n);
+		page = ext2_get_page(dir, n, dir_has_error);
 		if (!IS_ERR(page)) {
 			kaddr = page_address(page);
 			de = (ext2_dirent *) kaddr;

@@ -391,7 +396,9 @@ struct ext2_dir_entry_2 * ext2_find_entr
 				de = ext2_next_entry(de);
 			}
 			ext2_put_page(page);
-		}
+		} else
+			dir_has_error = 1;
+
 		if (++n >= npages)
 			n = 0;
 		/* next page is past the blocks we've got */

@@ -414,7 +421,7 @@ found:
 
 struct ext2_dir_entry_2 * ext2_dotdot (struct inode *dir, struct page **p)
 {
-	struct page *page = ext2_get_page(dir, 0);
+	struct page *page = ext2_get_page(dir, 0, 0);
 	ext2_dirent *de = NULL;
 
 	if (!IS_ERR(page)) {

@@ -487,7 +494,7 @@ int ext2_add_link (struct dentry *dentry
 	for (n = 0; n <= npages; n++) {
 		char *dir_end;
 
-		page = ext2_get_page(dir, n);
+		page = ext2_get_page(dir, n, 0);
 		err = PTR_ERR(page);
 		if (IS_ERR(page))
 			goto out;

@@ -655,14 +662,17 @@ int ext2_empty_dir (struct inode * inode
 {
 	struct page *page = NULL;
 	unsigned long i, npages = dir_pages(inode);
+	int dir_has_error = 0;
 
 	for (i = 0; i < npages; i++) {
 		char *kaddr;
 		ext2_dirent * de;
-		page = ext2_get_page(inode, i);
+		page = ext2_get_page(inode, i, dir_has_error);
 
-		if (IS_ERR(page))
+		if (IS_ERR(page)) {
+			dir_has_error = 1;
 			continue;
+		}
 
 		kaddr = page_address(page);
 		de = (ext2_dirent *)kaddr;

fs/ext3/dir.c +7 -3

@@ -102,6 +102,7 @@ static int ext3_readdir(struct file * fi
 	int err;
 	struct inode *inode = filp->f_path.dentry->d_inode;
 	int ret = 0;
+	int dir_has_error = 0;
 
 	sb = inode->i_sb;

@@ -148,9 +149,12 @@ static int ext3_readdir(struct file * fi
 		 * of recovering data when there's a bad sector
 		 */
 		if (!bh) {
-			ext3_error (sb, "ext3_readdir",
-				"directory #%lu contains a hole at offset %lu",
-				inode->i_ino, (unsigned long)filp->f_pos);
+			if (!dir_has_error) {
+				ext3_error(sb, __func__, "directory #%lu "
+					"contains a hole at offset %lld",
+					inode->i_ino, filp->f_pos);
+				dir_has_error = 1;
+			}
 			/* corrupt size?  Maybe no more blocks to read */
 			if (filp->f_pos > inode->i_blocks << 9)
 				break;

fs/ext4/dir.c +8 -3

@@ -102,6 +102,7 @@ static int ext4_readdir(struct file * fi
 	int err;
 	struct inode *inode = filp->f_path.dentry->d_inode;
 	int ret = 0;
+	int dir_has_error = 0;
 
 	sb = inode->i_sb;

@@ -147,9 +148,13 @@ static int ext4_readdir(struct file * fi
 		 * of recovering data when there's a bad sector
 		 */
 		if (!bh) {
-			ext4_error (sb, "ext4_readdir",
-				"directory #%lu contains a hole at offset %lu",
-				inode->i_ino, (unsigned long)filp->f_pos);
+			if (!dir_has_error) {
+				ext4_error(sb, __func__, "directory #%lu "
+					   "contains a hole at offset %Lu",
+					   inode->i_ino,
+					   (unsigned long long) filp->f_pos);
+				dir_has_error = 1;
+			}
 			/* corrupt size?  Maybe no more blocks to read */
 			if (filp->f_pos > inode->i_blocks << 9)
 				break;

Patches currently in stable-queue which might be from [email protected] are

queue-2.6.26/ext-avoid-printk-floods-in-the-face-of-directory-corruption.patch