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authorEric Sandeen <sandeen@redhat.com>2008-10-09 11:15:52 -0400
committerTheodore Ts'o <tytso@mit.edu>2008-10-09 11:15:52 -0400
commit9d9f177572d9e4eba0f2e18523b44f90dd51fe74 (patch)
tree91104778c9f4bc15fc483e44314733818865b264
parentcf17fea6575cb1739552e1d0cb2b446305ee3d0c (diff)
ext4: 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 <sandeen@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: linux-ext4@vger.kernel.org Cc: Eugene Teo <eugeneteo@kernel.sg>
-rw-r--r--fs/ext4/dir.c11
1 files changed, 8 insertions, 3 deletions
diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
index d40da316921d..3ca6a2b7632d 100644
--- a/fs/ext4/dir.c
+++ b/fs/ext4/dir.c
@@ -102,6 +102,7 @@ static int ext4_readdir(struct file *filp,
102 int err; 102 int err;
103 struct inode *inode = filp->f_path.dentry->d_inode; 103 struct inode *inode = filp->f_path.dentry->d_inode;
104 int ret = 0; 104 int ret = 0;
105 int dir_has_error = 0;
105 106
106 sb = inode->i_sb; 107 sb = inode->i_sb;
107 108
@@ -148,9 +149,13 @@ static int ext4_readdir(struct file *filp,
148 * of recovering data when there's a bad sector 149 * of recovering data when there's a bad sector
149 */ 150 */
150 if (!bh) { 151 if (!bh) {
151 ext4_error(sb, "ext4_readdir", 152 if (!dir_has_error) {
152 "directory #%lu contains a hole at offset %lu", 153 ext4_error(sb, __func__, "directory #%lu "
153 inode->i_ino, (unsigned long)filp->f_pos); 154 "contains a hole at offset %Lu",
155 inode->i_ino,
156 (unsigned long long) filp->f_pos);
157 dir_has_error = 1;
158 }
154 /* corrupt size? Maybe no more blocks to read */ 159 /* corrupt size? Maybe no more blocks to read */
155 if (filp->f_pos > inode->i_blocks << 9) 160 if (filp->f_pos > inode->i_blocks << 9)
156 break; 161 break;